Term
|
Definition
| Fluorescence in situ hybridization |
|
|
Term
| What two things mark the centromere? |
|
Definition
| Fluorescence in situ hybridization (FISH) and the localization of satellite DNA |
|
|
Term
|
Definition
|
|
Term
| What color does satellite DNA stained with fluorescently labeled avidin which binds biotin yield? |
|
Definition
|
|
Term
| Red is the color that what stained with what yields? |
|
Definition
| DNA stained with Propidium iodide |
|
|
Term
| Mutations are typically, but not always... |
|
Definition
|
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Term
|
Definition
| sequences and human disease |
|
|
Term
| How does the trinucleotide repeats expand? |
|
Definition
| Through DNA replication from one generation to another |
|
|
Term
|
Definition
|
|
Term
|
Definition
| study of all the proteins |
|
|
Term
| How can protein interactions be analyzed globally? |
|
Definition
| Via the High-throughput format |
|
|
Term
| Are protein interactions uniform? |
|
Definition
| Absolutely not. there are hubs. the average number of protein interactions is 8. |
|
|
Term
| What is an example of something that non muscle motility depends on? |
|
Definition
| actin filaments and members of the myosin family |
|
|
Term
| A variety of what dictat the organization and behavior of actin filaments inside cells? |
|
Definition
|
|
Term
| what categories are acting binding proteins broken into? |
|
Definition
- Nucleating Proteins
- Monomer-sequestering protein
- End Blocking (capping) proteins
- Monomer-polymerizing proteins
- actin filament-depolymerizing proteins
- Cross-linking proteins
- Filament Serving Proteins
- Membrane-binding proteins
|
|
|
Term
| Explain: Nucleating Proteins |
|
Definition
Essential for nucleation, where two or three actin monomers come together in the proper orientation to form the polymer.
Example: Arp2/3 complex
Function: formation of actin filament |
|
|
Term
| Explain: Monomer-sequestering Protein |
|
Definition
Bind to actin-ATP (G-actin) monomers prevent them from forming polymers
Example: thymosins
Function: REgulation of depolymerization and polymerization |
|
|
Term
| Explain: End-blocking (capping) proteins |
|
Definition
Regulate the length of the actin filament by binding to one or the other end of the filament, forming a cap.
Example: Tropomodulin
Function: Regulation of the length of actin filaments |
|
|
Term
| Explain: Monomer-polymerizing Proteins |
|
Definition
Promotes the growth of actin filaments
Example: Profilin
Function: Growth of filaments |
|
|
Term
| Explain: Actin filament-depolymerizing Proteins |
|
Definition
Play a role in the rapid turnover os actin filaments
Example: Cofilin
Function:Essential for cell locomotion, phagocytosis, and cytokinesis |
|
|
Term
| Explain: Cross-linking proteins |
|
Definition
These alter the 3D organization of a population of actin filaments. these prtoeins have two or more actin binding sites and can cross-link two or more separate actin filaments.
Example: filamin
Function: rigidity and support |
|
|
Term
| Explain: Filament-severing Proteins |
|
Definition
They bind to the side of a filament and breaks it in two
Example: Gelsolin
Function: Promotes the incorporation of monomers |
|
|
Term
| Explain: Membrane-binding Proteins |
|
Definition
They link actin filaments to the plasma membrane.
Example: Spectrin
Function: For the contraction of non-muscle cells, cell locomotion, phagocytosis, or cytokinesis. |
|
|
Term
| Actin filaments work together with what type of motor? |
|
Definition
|
|
Term
| Non muscle motility and contraction |
|
Definition
- Cell locomotion is required for many activities: tissue and organ development, formation of blood vessels, development of the axon, wound healing and protection against infection, and the spread of cancerous
- axonal outgrowth: tip of the axon, growth cone is highly motile and elongates the axon by directed movement.
- changesin cell shape during embryonic development: formation of parts of the body.
|
|
|
Term
| How does cell movement by lamellipodia extensions work? |
|
Definition
Lamellipodia: leading edge, extended out from the cell, broad, flattened, veil like protrusion.
1. Lemellipodia extend by myosin 1
2. Adheres to the surface
3. Pulled by myosin
4. Release and reset |
|
|
Term
| what is the rate at which cell movement occurs |
|
Definition
|
|
Term
| What doesn't the body of the lamellipodium contain? |
|
Definition
| It does not contain myosin, but it does contain actin |
|
|
Term
| Where is the myosin located? |
|
Definition
| It is concentrated in a band behind the lamellipodium |
|
|
Term
|
Definition
- Rod-like microspikes (arrows) within the veil of the lamellipodium
- Filopodia (arrowheads0 project out ahead of the leading edge of the lamellipodium
|
|
|
Term
| How is the neural plate formed? |
|
Definition
| During embryonic development, microtubules help elongate neural ectoderm cells to help form the neural plate |
|
|
Term
| what could cause the nervous system not to form? |
|
Definition
| Later in embryonic development Microfilaments and myosin 1 help to role up the neural tube. If this doesn't happen the nervous system will not form |
|
|
Term
| Give some information about the nucleus |
|
Definition
- It is also referred to as the "control center". Its a membrane-enclosed organelle
- It contains most of the cells genetic material organized in the form of chromosomes
|
|
|
Term
| what is the function of the nucleus |
|
Definition
| Its function is to maintain the integrity of its genetic material, and to control the activities of the cell by regulating gene expression |
|
|
Term
|
Definition
- Nuclear envelope
- Nuclear Lamina
- Nucleoplasm
- Nucleolus
- Nuclear Matrix
- Chromosomes
|
|
|
Term
|
Definition
| a double membrane that encloses the entire organelle and separates its contents from the cellular cytoplasm. It is continuous with the Endoplasmic Reticulum |
|
|
Term
|
Definition
| A meshwork within the nucleus that adds mechanical support, allow movement of molecules across the envelope. It can interact with chromatin |
|
|
Term
|
Definition
| This is the fluid substance in which the solutes of the nucleus are dissolved. Analogous to cytoplasm. |
|
|
Term
|
Definition
| Electron dense structure surrounded by a membrane. Function in the synthesis of ribosomal RNA and the assembly of ribosomes. |
|
|
Term
|
Definition
| Its the protein containing fibrillar network |
|
|
Term
|
Definition
| The cells genetic material in the form of multiple linear DNA molecules is organized into structures called Chromosomes. |
|
|
Term
|
Definition
Besides the nucleolus, the nucleus contains a number of other non-membrane delineated bodies.
Examples include: Cajal bodies, Gemini of coiled bodies, polymorphic interphase karysomal association (PIKA), promyelocytic leukemia (PML) bodies, praspeckles and splicing speckles.
A lot of information is not known about these but they are significant becaise they show that the nucleoplasm is not uniform but rather is functional and organized |
|
|
Term
| What is the function of the nucleus? |
|
Definition
| The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during the cell cycle. |
|
|
Term
| What does the nucleus do that allows levels of gene regulation? |
|
Definition
| It provides a site for genetic transcription that is segregated from the location of translation in the cytoplasm. |
|
|
Term
|
Definition
- Two cellular membranes arranged parallel to one another and are separated by 10-50 nm
- It serves as a barrier for ions, solutes and macromolecules from passing freely between the nucleus and cytoplasm except through the nuclear pore complex
- The average cell contains several thousand nuclear pores
- Outer membrane is generally studded with ribosomes and is continuous with the ER
|
|
|
Term
|
Definition
- Filamentous meshwork
- Provides mechanical support to the nuclear envelope, serves as a site of attachment for chromatin fibers at the nuclear periphery, and some role in DNA replication and transcription
- Filaments are composed of polypeptides called lamins, family of the intermediate filaments
|
|
|
Term
| What about lamina are responsible for human diseases? |
|
Definition
Mutations
A rare form of muscular dystrophy, Hutchinson-Gilford progeria syndrome (HGPS), characterized by premature aging and death during teenage years |
|
|
Term
| what are the three primary structures in the nuclear pore complex? |
|
Definition
- The cytoplasmic filaments: towards the cytoplasm
- A central eight-fold symmetrical ring: in the nuclear envelope.
- A nuclear basket: Towards the nucleoplasm
|
|
|
Term
| Each nuclear pore is composed of apporxiamtely how many proteins, and what are they known as? |
|
Definition
| approx. 30 proteins which are known as nucleoporins (nup) |
|
|
Term
| nuclear pores allow the transport of what type of molecules across the nuclear envelope? |
|
Definition
| Water-soluble molecules. This transport includes RNA (both mRNA and tRNA) and ribosomes moving from nucleus to cytoplasm and proteins (such as DNA polymerase, lamins, carbohydrates) signal molecules and lipids to move into the nucleus from the cytoplasm |
|
|
Term
| what size molecules are able to pass through the nuclear pore complex by passive diffusion? |
|
Definition
|
|
Term
| efficient transport through the complex requires what? |
|
Definition
|
|
Term
|
Definition
| move macromolecules from the cytoplasm into the nucleus |
|
|
Term
|
Definition
| move macromolecules from the nucleus to the cytoplasm |
|
|
Term
| Import of proteins from the cytoplasm to the nucleus |
|
Definition
- Need a NLS nuclear localization signal
- Enables the protein to pass through the nuclear pore and enter the nucleus
- any protein with a NLS will be taken up by importins to the nucleus
- importin first binds to NLS acts as a brindge for importin-beta to attach
- Importin beta, importin alpha-cargo complex is inside the nucleus, Ran GTP binds to importin beta and displaces complex
- Once the complex is in the nucleus, Ran GTP binds to importin-beta and displaces complex
|
|
|
Term
| Is Translocation through the pore energy dependent? |
|
Definition
| NO, but the importin cycle needs the hydrolysis of 2 GTPs and IS enegry depepndent |
|
|
Term
| Importin Joins with a protein that has what? |
|
Definition
| One that has a Nuclear Localization Signal (NLS Proterin) |
|
|
Term
| A brief description of the import of proteins from the cytoplasm to the nucleus |
|
Definition
- Import joins with a protein that has a nuclear Localization Signal (NLS Protein)
- This complex then binds to pore cytoplasmic filaments
- Then the complex moves into the nuclear pore and then into the nucleus
|
|
|
Term
| during the import of proteins from the cytoplasm to the nuleus what displaces the complex |
|
Definition
| The binding of Ran-GTP to importin, the importin with tt Ran-GTP is transported back to the cytoplasm |
|
|
Term
| Export of Proteins/RNA from the nucleus to the cytoplasm |
|
Definition
- Some nuclear proteins need to be exported from the nucleus to the cytoplasm, as do ribosomal subunits and mRNA
- Need a nuclear export sequence (NES) that are recognized by exportin
- Exportin-Ran GTP complex moves through the pore into the cytoplasm
- GTP is hydrolyzed and NES protein is released
|
|
|
Term
| Is translocation through the pore energy dependent? |
|
Definition
| NO it is not, but dissociation of exportin-NES protein complex IS energy dependent |
|
|
Term
| Where are ribosomal subunits assembled? |
|
Definition
|
|
Term
| What do ribosomal subunits contain? |
|
Definition
|
|
Term
Ribosomal subunits move from the nucleus to where?
|
|
Definition
|
|
Term
|
Definition
- Insoluble fibrillar network
- when isolated from nuclei treated with nonionic detergents and high salt (2M NaCl) which removes lipids and all of the chromosomal proteins (histones) the DNA is seen as a halo surrounding a residual nuclear core
- when DNA is digested with DNAse, the structure that remains process the same shape as the nucleus, but is composed of a network of thin protein-coating fibrils crisscrossing through nuclear space
|
|
|
Term
| What is the function of the nuclear matrix? |
|
Definition
| It is a skeleton to maintain shape, scaffold on which to organize chromatin, maybe be involved in DNA replication and transcription |
|
|
Term
| How to get nuclear matrix: |
|
Definition
- Purify nuclei
- detergent extract with triton to ermove membranes
- Add DNAse and RNAse to remove DNA and RNA
- Add high salt to remove ionically bound material
- What remains is the nuclear matrix
|
|
|
Term
| How do you isolate nuclei? |
|
Definition
| Homogenize cells, centrifuge at low speeds. Nuclei are what is left in the pellet |
|
|
Term
| What does the detergent do? |
|
Definition
|
|
Term
|
Definition
| There are many different physical states of chromatin |
|
|
Term
| What can Chromatin be broken down into? |
|
Definition
|
|
Term
| What plays a role in directing heterochromatization? |
|
Definition
|
|
Term
| RNA recruits the enzyme which is guided where? |
|
Definition
| to a portion of chromatin that is in the euchromatic state |
|
|
Term
| HMTase which catalyzes ht e addition of methyl groups to H3 core histones serve as |
|
Definition
| binding sites for the HP1 protein |
|
|
Term
| Once HP1 is bound to the histone tails what can happen? |
|
Definition
| THe chromatin can be packaged into higher order |
|
|
Term
Flow of information in a eukaryotic cell
Steps 1&2 |
|
Definition
- Selected sites (genes) on the DNA are transcribed into pre-mRNA
- these are processed into messenger RNA's (mRNA)
|
|
|
Term
Flow of information in a eukaryotic cell
Steps 3-5 |
|
Definition
3. mRNA's are transported out pf the nucleus into the cytoplasm through nuclear pores
4. In the cytoplasm mRNA is translated into polypeptides by ribosomes that move along the mRNA
5. Following translation, the polypeptide folds to assume its native conformation. |
|
|
Term
| mRNA is the intermediate between what two things? |
|
Definition
| the gene and the polypeptide |
|
|
Term
| transcription to translation is assembled as a complementary copy of what? |
|
Definition
| of one of yhr to DNA strands that make-up a gene |
|
|
Term
|
Definition
| the synthesis of an RNA from a DNA template |
|
|
Term
| Why does the mRNA retain the same information as the gene itself? |
|
Definition
| because its nucleotide sequence is complementary to that of the gene from which it is transcribed. |
|
|
Term
| Once in the cytoplasm, the mRNA serves as a template to do what? |
|
Definition
| to transcribe into protein |
|
|
Term
| Proteins are synthesized in the cytoplasm by a complex process called what? |
|
Definition
|
|
Term
| In mRNA as in DNa, genetic information is encoded in the sequence of what? |
|
Definition
| Nucleotides arranged into codons consisting of 3 bases each. |
|
|
Term
| Each codon encodes for a soecific amino acid except for what? |
|
Definition
| The stop codon which terminates protein synthesis |
|
|
Term
| What are the two types of RNA that protein synthesis uses? |
|
Definition
| Transfer RNA (tRNA) and rRNA Ribosomal RNA |
|
|
Term
| What is Ribosomal RNA (rRNA)? |
|
Definition
| It is the central component of the ribosomes protein manufactoring mchinery. |
|
|
Term
| What is transfer RNA (tRNA)? |
|
Definition
| it mediates recognition of the codon and provides the corresponding amino acid. |
|
|
Term
| Transcription is also known as |
|
Definition
|
|
Term
| What is the process of creating an equivalent RNA copy of a sequence of DNA called? |
|
Definition
|
|
Term
| What is the first step leading to gene expression called? |
|
Definition
|
|
Term
| How is DNA read during transcription? |
|
Definition
|
|
Term
| How many of the 2 DNA strands is used during transcription? And what is it, are they called? |
|
Definition
| Only one of the two are used and it is called the template strand |
|
|
Term
| Why is only one strand of DNA used in transcription? |
|
Definition
| Because RNA is single stranded |
|
|
Term
| What is the name of the other DNA strand that is not used and why? |
|
Definition
| The coding stran becasue its sequence is the same as the newly created RNA transcript |
|
|
Term
| How many distinct enzymes do eukaryotes have for transcribing RNA in the nucleus? |
|
Definition
|
|
Term
| What is each distinct enzyme used for? |
|
Definition
| Each is responsible for synthesizing a different group of RNA |
|
|
Term
| What is a transcriptional unit? |
|
Definition
| a stretch of DNA that is being synthesized into RNa |
|
|
Term
What is the primary transcript?
aka pre-RNA |
|
Definition
| The initial precursor RNA that is equivalent inlength to the full length of the DNA transcribed |
|
|
Term
| What are the four stages of transcription? |
|
Definition
- Pre-initiation
- Initiation
- Promoter clearance
- Elongation and Termination
|
|
|
Term
|
Definition
| The RNA polymerase, requires the presence of a core promoter, which is the region of DNA that promotes transcription, sequence in the DNA. This location is found at -30, -75, and -90 bps which is upstream from the start site of transcription. These sequences are essential for transcriptional initiation. The most common core promoter is the TATA box at -30 bps. |
|
|
Term
|
Definition
| this is the binding site for a transcriptional factor. Five other transcriptional factors and RNA polymerase come together around the box to form the pre-initiation complex. |
|
|
Term
|
Definition
| (of transcription) occurs only after the binding of transcriptional factors and RNA polymerase binds to the promoter |
|
|
Term
| During promoter clearance what must clear the promoter? |
|
Definition
| The first bond must be synthesized the RNA polymerase must clear the promoter |
|
|
Term
| Once the transcript reaches 23 nucleotides what no longer happens? |
|
Definition
| it no longer slips and elongation can occur |
|
|
Term
| Is promoter clearance an energy-dependent process? |
|
Definition
|
|
Term
What is used as a template for RNA synthesis? |
|
Definition
| One strand of DNA, the template strand (or noncoding strand) |
|
|
Term
| As transcritption proceeds, RNA polymerase traverses the template strand and uses base pairing complementary with what? |
|
Definition
| With the DNA template to create and RNA copy |
|
|
Term
| Can many mRNA be produced from a single copy of a gene? |
|
Definition
| Yes because transcription can involve multiple RNa polymerases on a single DNa template and multiple rounds of transcrition |
|
|
Term
| Elongation also includes a proofreading mechanism that does what? |
|
Definition
| can replace incorrectly incorporated bases. |
|
|
Term
| Is termination in eukaryotes in well understood? |
|
Definition
|
|
Term
| What does termination in eukaryotes involve? |
|
Definition
| the cleavage of the new transcript followed by template-dependent addition of AAA's at its 3' end in a process called polyadenylation |
|
|
Term
| What does initiation of transcription require? |
|
Definition
| that nucleosomes change their structure, becoming less compact. This makes DNA accessible to the transcription complex |
|
|
Term
| What happens to nucleosomes during elongation of RNA? |
|
Definition
| Nothing they remain intact |
|
|
Term
| What does a mRNA molecule begin and end with? |
|
Definition
| begins with transcription and ends in degredation |
|
|
Term
| During its life what can happen toan mRNA molecule prior to translation? |
|
Definition
| the molecule may be processed, edited, and transported |
|
|
Term
| Eukaryotic mRNA require what? |
|
Definition
| extensive processing and transport. prokaryotic molecules do not. |
|
|
Term
| 5' end capping involves what? |
|
Definition
| the addition of 7-methylguanosine to the 5'end |
|
|
Term
| When does 5' capping occur? |
|
Definition
| immediately after initiation |
|
|
Term
| What does 5' capping ensure? |
|
Definition
| the messenger RNA's stability while it undergoes translation |
|
|
Term
|
Definition
| the addtion of a poly (A) tail to an RNA molecule |
|
|
Term
| Why is the Poly(A) tail important? |
|
Definition
| because it is important for the nuclear export, tanslation, and stability of mRNA |
|
|
Term
| What is polyadenylation combined with? |
|
Definition
|
|
Term
| What is the poly (A) tail? |
|
Definition
| a stretch of RNA which only has a stretch of adenines. |
|
|
Term
|
Definition
| the process by which introns are removed from the pre-mRNA and the ramining exons which are connected to reform a single continuous molecule |
|
|
Term
|
Definition
| regions of the RNA that do not code for protein |
|
|
Term
| What must be present in nucleotide sequences athe the splice sites of pre-mRNA? |
|
Definition
| breaks in the strand must be introduced at 5' and 3' ends (splice sites of each intron) and the exons must be covalently joined. |
|
|
Term
| what type of sequences act in splicing? |
|
Definition
|
|
Term
| What is alternative splicing? |
|
Definition
| Many pre-mRNA s can be spliced in multiple ways to produce different mature mRNAs that encode different protein sequences |
|
|
Term
| What is the 5' cap critical for? |
|
Definition
| recognition and proper attachment of mRNA to the ribosome as well as protection from exonnucleases. It may also be important for other essential processes such as aplicing and transport |
|
|
Term
|
Definition
| composed of codons which are decoded and translated to protein. Begin with a start codon and end with a stop codon. |
|
|
Term
| Untranslated Regions (UTRs) |
|
Definition
| sections of the mRNA before the start codon and after the stop codon are not translated. May function for mRNA stability, mRNA stabilization, and translational efficiency. |
|
|
Term
|
Definition
| promotes export from the nucleus and translation, and protects the mRNA from degredation |
|
|
Term
|
Definition
|
|
Term
|
Definition
| large protein complex that catalyzes the splicing reaction |
|
|
Term
| What is the central component of the ribosome? |
|
Definition
| Ribosomal ribonucleic acid (rRNA) |
|
|
Term
| What is the function of rRNA? |
|
Definition
| to decode mRNA into amino acid |
|
|
Term
| What is the ribosome composed of? |
|
Definition
| two subunits named for how rapidly they sediment during centrifugation |
|
|
Term
| What type of subunits make up the ribosome? |
|
Definition
| Large and small subunits and many ribosomal proteins |
|
|
Term
|
Definition
|
|
Term
| What do svedburg units represent? |
|
Definition
| measures of sedimentation rate rather than mass. Sedimentation rate of each subunit is affected by its shape as well as its mass |
|
|
Term
| More than 80% of the RNA in most cells consists of what? |
|
Definition
|
|
Term
| Where is the DNA called rDNA and what is the function? |
|
Definition
| It is clustered around in the nucleolus which function in producing ribosomes |
|
|
Term
What is the bulk of the nucleolus composed of? |
|
Definition
| nescent ribosomal subunits that give the nucleolus a granular appearance. |
|
|
Term
| In synthesizing the rRNA precursor how are the rRNA genes arranged? |
|
Definition
| in tandem. They are separated by non transcribed spacer regions |
|
|
Term
| How many distinct ribosomal RNAs do eukaryotic ribosomses? |
|
Definition
4
3 in the large subunit and 1 in the small subunit
|
|
|
Term
| What is the transfer ribonucleic acid (tRNA)? |
|
Definition
| A small RNA molecule that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site during translation |
|
|
Term
|
Definition
| a three base codon region that can base pair to the corresponding 3 base codon region on mRNA |
|
|
Term
| How many types of amino acids can each type of tRNA molecule be attached to? |
|
Definition
|
|
Term
| How many tRNA genes are found in the small clusters around the genome in humans? |
|
Definition
|
|
Term
| What type of sturctures does tRNA have? |
|
Definition
| primary, secondary, and tertiary |
|
|
Term
| Tertiary structure of tRNA |
|
Definition
tRNA is folded into two double helices arranged in the shape of an L
All tRNA have similar structure but unique anticodon |
|
|
Term
|
Definition
| a unit made up of three nucletides that correspond to the three bases of the codon on the mRNA |
|
|
Term
| What is another name for the anticdon |
|
Definition
|
|
Term
| What is the phenomenom that allows some anticodons to pair with more than one codon? |
|
Definition
|
|
Term
| What is the wobble hypothesis? |
|
Definition
| the interchangability of the base of the 3rd position lead francis crick to propose that the same tRNA may be able to recognize more than one codon |
|
|
Term
| example of wobble hypothesis |
|
Definition
U of the anticodon can pair with A or G of the mRNA
G of the anticodon can be paired with U or C of the mRNa |
|
|
Term
| When is amino acid activation important? |
|
Definition
| duing polypeptide synthesis that each tRNA molecule be attached to the correct amino acid |
|
|
Term
| Amino acids are covalently linked to the 3' ends of tRNA by an enzyme called what? |
|
Definition
| aminoacyl-tRNA synthetases |
|
|
Term
| After energy is used to from ATP to activate amino acid, it is transferred to what |
|
Definition
|
|
Term
| Codons of the mRNA are interpreted according to what? |
|
Definition
| the recognition abilities of the aaRS |
|
|
Term
| What is a non-coding RNA (ncRNA)? |
|
Definition
| A functional RNA molecule that is not translated into a protein |
|
|
Term
| RNA molecules can directly regulate what? |
|
Definition
|
|
Term
| Small interfering RNA (siRNA) |
|
Definition
also known as short interfering RNA or SIlencing RNA
- a class of double stranded RNA molecules
- 20-25 nucleotides in length
- involved in RNA interference (RNAi) pathway, where it interferes with the expression of a specific gene
|
|
|
Term
| What type of structure does siRNA have? |
|
Definition
| a well defined structure: short, usually 21 nucleotides) double strand of RNA (dsRNa) with a 3' overhand on either end |
|
|
Term
| Each end has what type of group? |
|
Definition
| 5' phosphate group and 3' hydroxyl group |
|
|
Term
| siRNA structure is the result of what? |
|
Definition
| processing by an enzyme (dicer) which converts either long dsRNA or small hairpin RNA into siRNa |
|
|
Term
| RNA as an interference tool |
|
Definition
| siRNA can be introduced into cells by various transfection methods to bring about the specific knockdown of a gene of interest. |
|
|
Term
| RNA as an interference results in |
|
Definition
| the destruction of mRNA's thus interfering with gene expression. |
|
|
Term
| Mechanism of RNA interference (RNAi) |
|
Definition
| It is part of a greater phenomona of RNA silencing, in which small RNAs inhibit gene expression in various ways |
|
|
Term
| The steps of RNAi include |
|
Definition
- dsRNa is cleaved into small interfering RNAs (siRNA) by an enzyme called dicer
- The small dsRNAs are loaded into a complex named RISC that bind siRNA to a target RNA
- mRNA is degraded
|
|
|
Term
|
Definition
small RNAs that suppress the movement of transposable elements in the germline, therefore function in the germ cells..
they lack primary sequence conservation and increased complexity. |
|
|
Term
| Each ribosome has how many RNA binding sites? |
|
Definition
|
|
Term
| What does the A site bind? |
|
Definition
| a tRNA bound to an amino acid (aminoacyl-tRNA) |
|
|
Term
| What does the P site bind? |
|
Definition
| a tRNA bound to the peptide being synthesized (peptidyl-tRNA) |
|
|
Term
| What does the E site bind? |
|
Definition
| a free tRNA before it exits the ribosome |
|
|
Term
| Where does protein synthesis begin? |
|
Definition
| at a start codon AUG near the 5' end of the mRNA |
|
|
Term
| Where does mRNA bind first? |
|
Definition
| the P site of the ribosome |
|
|
Term
| How is the ribosome able to identify the start codon |
|
Definition
| via the use of the Shine-Dalgarno sequence of the mRNA in prokaryotes and Kozak box in eukaryotes |
|
|
Term
| What is Shine-Dalgarno sequence? |
|
Definition
a ribosomal binding site in the mRNA generally located 3-10 bps upstream of the start codon AUG
It is only in prokaryotes and includes AUG start codon in eukaryotes ACCAUGG |
|
|
Term
| Where does translation occur? |
|
Definition
| in the cytoplasm where the ribosomes are located |
|
|
Term
What are the ingredients for the assembly of a protein? |
|
Definition
| various tRNAa with their attached amino acids, a messenger RNA, numerous proteins having different functions, cations and GTP |
|
|
Term
| What are the three distinct activities of Protein Synthesis? |
|
Definition
Initiation
Elongation
Translation |
|
|
Term
|
Definition
| the ribosome attaches to the mRNA at a precise site, intiation (start) codon, AUG. Binding to the start codon puts the ribosome on the proper froam so it can be read correctly, the entire message. |
|
|
Term
| What are the 3 steps of Initiation? |
|
Definition
- Bringing the small ribosomal subunit to the initiation codon
- Bringing the first aa-tRNA into the ribosome
- Assembling the complete initiation complex
|
|
|
Term
| What are Initiation factors? |
|
Definition
|
|
Term
| How many initiation factors are needed for initiation in Eukaryotes? |
|
Definition
| at least 12 different ones. called eIFs |
|
|
Term
|
Definition
- Aminoacyl-tRNA selection
- Peptide Bond Formation
- Translocation
- Releasing the deacylated tRNA
|
|
|
Term
| Is the formation of a peptide bond energy dependent? |
|
Definition
| No, but it uses an enzyme called peptidyl transferase, a component of the large subunit of the ribosome |
|
|
Term
| What is translocation driven by? |
|
Definition
| conformational changes in another elongation factor which is attached to GTP |
|
|
Term
| What is hydrolyzed for each cycle of elongation? |
|
Definition
|
|
Term
| how long does each cycle of longation take? |
|
Definition
|
|
Term
| What are frame shift mutations? |
|
Definition
| they shift the reading frame and occur when a single bp is either added or deleted from the DNA . It can lead to the assembly of an entirely abnormal sequence of aa from the point of the mutation or will result in a truncated polypeptide |
|
|
Term
|
Definition
There are 3 stop codons: UAA, UAG, UGA
when the ribosome reaches a stop codon the signal is read to stop further elongation and release the polypeptide associated with the last tRNA |
|
|
Term
|
Definition
| Many ribosomes caan transcribe the same piece of mRNA creating many copies of the same protein. It is this complex of ribosomes and mRNA that are called polyribosomes. |
|
|
Term
| REgulation of gene expression in eukaryotic cells occur primarily at three distinct levels |
|
Definition
- Transcriptional level control
- Processing-level control
- Translation level control
- Post-translation level control
|
|
|
Term
| TRanscriptional level control |
|
Definition
determines whether a particular gene can be transcribed, if so how often
|
|
|
Term
|
Definition
| determines path by which the primary mRNA transcript is processed into a mRNA that can be translated into a polypeptide |
|
|
Term
| Translation level control |
|
Definition
| determines whether a particular mRNA is actually translated and is so, how often and for how long a period |
|
|
Term
| Post-translation level control |
|
Definition
| determines the survival of proteins |
|
|
Term
| Transcriptional level control subdivision |
|
Definition
- Specificity Factors (sequence-specific transcriptional factors)
- General transcription factors: form the pre-initiation factors
- Enhancers
|
|
|
Term
|
Definition
| binds to various regulatory sites of particular genes and can act as either transcriptional activators that stimulate transcription of the adjacent gene or transcritpional repressors that inhibit transcription |
|
|
Term
|
Definition
| DNA binding protein that regulates one or more genes by increasing the rate of transcription. and can bind to enhancers. |
|
|
Term
|
Definition
| bind DNA binding activators to enhance transcription and are large complexes that consists of numerous subunits |
|
|
Term
| What are they two types of activators? |
|
Definition
- Those that interact with components of general TFs and RNA polymeraseII
- those that act on chromatin to convert it to a more transcriptional friendly form
|
|
|
Term
| Structure of translation Factors |
|
Definition
| The contain different domains that mediate different functions |
|
|
Term
| Three parts of the structure of TF's |
|
Definition
1. DNA binding domain that binds to a specific sequence in the DNA
2. Activation Domain that regulates transcription by interacting with other proteins
3. Signal sensing domain (a ligand binding domain) which senses external signals and in response transmit these signals to the rest of the transcription complex resulting in up or down regulation of gene expression |
|
|
Term
| Where are general transcription factors from? |
|
Definition
| the pre-initiation complex |
|
|
Term
|
Definition
| A short region of DNA that can be bound with proteins to enhance transcription |
|
|
Term
| Where are enhancers located? |
|
Definition
| within 100 bps upstream of the TATA box |
|
|
Term
| What are two regulatory sequences found in many eukaryotic genes? |
|
Definition
| CCAAT and GGGCGG also known as GC box |
|
|
Term
| How do enhancers function? |
|
Definition
| like promoters, by binding transcription factors that then regulate RNA polymerase |
|
|
Term
| With regard to enhancers, what does DNA looping allow? |
|
Definition
| a transcription factor bound to a distant enhancer to interact with RNA polymerase or general transcription factors at the promoter |
|
|
Term
| What is the order in Processing level control? |
|
Definition
| First is Alternative splicing and then comes RNA editing in which specific nucleotides are converted to other nucleotides after the RNA has been transcribed and can create new splice sites, generate stop codons, or lead to amino acid substitiutions. IT is important in the nervous system |
|
|
Term
| How does translation level control go? |
|
Definition
| Through interactions between specific mRNAs various proteins and micro RNAs |
|
|
Term
| What are the three steps of translation level control? |
|
Definition
1. cytoplasmic localization of mRNAs
2. control of RNA translation
3. control of RNA stability |
|
|
Term
| Cytoplasmic klocalization of mRNAs |
|
Definition
| the mRNAs are translated at the site os localization where the newly synthesized protein accumulates |
|
|
Term
| Control of mRNA translation |
|
Definition
| mRNA can be synthesized and stored, in an unfertilized egg, in the cytoplasm in an inactive state. |
|
|
Term
| Control of mRNA stability |
|
Definition
| their is regulation in the survival of the mRNA, most eukaryotic mRNa are long lived. And stability is controlled by length of 3' poly (A) tail. Those that lack a poly(A) tail are quickly degraded |
|
|
Term
| How does degradation occur? |
|
Definition
| by two pathways beginning at the 5' and ending at 3' |
|
|
Term
| Posttranslational control |
|
Definition
has to do with:
stability of the protein and the length of time that specific proteins survive also provide a level of control. |
|
|
Term
|
Definition
| hollow, cylindrical, protein degrading machines that carry out the degradation of cellular proteins. they are found in the nucleus and the cytoplasm, and digest proteins that have been marked for destruction. |
|
|
Term
| Steps in the degradation of proteins by proteosome |
|
Definition
1. The protein to be degraded is covalently linked to a string of ubiquitin,
2. polyubiquitated protein bind to cap of proteosome
3.Ubiquitin chain is removed and unfolded protein is threaded into the centra chamber of proteosome
4&5. Inside the proteosome the protein is degraded by catalytic activity. |
|
|
Term
|
Definition
| The purpose is to copy the DNA and each strand of the original double stranded DNA serves as a template for the reproduction of the complementary strand |
|
|
Term
| What is produced from DNA replication? |
|
Definition
| two identical DNA molecules |
|
|
Term
| What ensures that replicated DNA is correct? |
|
Definition
| proof reading and error checking mechanism |
|
|
Term
| What did the Watson-Crick proposal make certain predictions about? |
|
Definition
| the behavior of DNA during replication |
|
|
Term
| In DNA replication each of the daughter duplexes should consist of what? |
|
Definition
| one complete strand inherited from the parental duplex and one complete strand that has been newly synthesized |
|
|
Term
| Why are the daughter duplexes called semi conservative? |
|
Definition
| Because each daughter duplex contains one strand from the parent structure |
|
|
Term
| Semi conservative replication |
|
Definition
| each daughter duplex contains one strand from the parent structure |
|
|
Term
|
Definition
| Two original strands would remain together after serving as a template as would two newly synthesized strands. One of the daughter duplexes would contain only newly synthesized DNA there is no mixing of old and new |
|
|
Term
|
Definition
| The prental strand would be broken into fragments and the new strand would be synthesized in short segments. The old and new fragments will join to for ma complete strand. and the daughter duplexes would contain strands that are composed of old and new DNA |
|
|
Term
| How can you determine between the three schemes of replication in bacteria? |
|
Definition
| Messelson-Stahl Expirements |
|
|
Term
| Messelson Stahl Expirements |
|
Definition
1. Grow bacteria on "heavy" nitrogen(15N) to metabolically label all DNA
2. Then switch to regular "light"nitrogen (14N) All newly replicated DNA will be "light" but the old parental DNa will be "heavy" |
|
|
Term
| How can you separate heavy DNA from light DNA? |
|
Definition
| Use the density gradient centrifugation to separate heavy and light DNA. They actually use cesium density gradients instead of sucrose. |
|
|
Term
| what is the result after dispersive replication after the first round of replication? |
|
Definition
|
|
Term
| What is the result after Conservative replication the first round of replication? |
|
Definition
| One is light the other is heavy |
|
|
Term
| What does it mean to be a hybrid? |
|
Definition
| EAch strand is half heavy half light |
|
|
Term
| What is the result after the first round of replication in semi conservative replication? |
|
Definition
| Both are hybrids. Outer makes the new inner on one and inner makes the new outer on the other. |
|
|
Term
| What are the second round products in dispersive replication? |
|
Definition
| All second round products are the same as the first. You will have 4 hybrids |
|
|
Term
| What are the second round products of conservative replication? |
|
Definition
| Two sets of DNA either all heavy or all light. |
|
|
Term
| WHat are the second round products of semi-conservative replication? |
|
Definition
| Two sets of DNA, one hybrid and the other all light. Outer makes new inner, inner makes new outer |
|
|
Term
| What are the real results of the Messelsohn STahl Expirement? |
|
Definition
1. In the beginning all of the DNA was heavy (15N)
2. After the first generation, all of the DNa was hybrid becasue each double stranded piece has one heavy (old parent) and one light new strand
3. In the second generation there are hybrid and light bands and there is so little of the original DNA left that it cant be seen |
|
|
Term
| How does the sucrose gradient separate? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| How can you tell that DNa replicates by DNA and not by transcription? |
|
Definition
| In replication A is paired with T in transcription A is paired with U |
|
|
Term
| What is the original strand called in DNA? |
|
Definition
| The template or Parental strand |
|
|
Term
| In DNA replication what is the newly synthesized strand called? |
|
Definition
|
|
Term
| Can gradient density centrifugation be used in DNA replication of Eukaryotes to separate chromatids or DNA from EUkaryotes? |
|
Definition
|
|
Term
| Mitotic cells must be used to see what? |
|
Definition
|
|
Term
| What does BrdU substitute for? |
|
Definition
|
|
Term
| What stains dark: BrdU or thymidine? |
|
Definition
| Thymidine BrdU stains light |
|
|
Term
| Is a hybrid of thymidine and BrdU dark or light? |
|
Definition
|
|
Term
| What does a dark color denote in the second generation? |
|
Definition
|
|
Term
| WHere does DNA replication begin? |
|
Definition
| specific locations in the genome called origins |
|
|
Term
| What forms a replication fork? |
|
Definition
| Unwinding of the DNA at origins and synthesis of new strands |
|
|
Term
| What is used to form a replication fork? |
|
Definition
|
|
Term
| What are origins also called? |
|
Definition
|
|
Term
| What are Eukaryotic origins called? |
|
Definition
| autonomous replicating sequences |
|
|
Term
| What is the ORC Origin Recognition Complex composed of? |
|
Definition
| six proteins that attach to the ARS (autonomous replicating sequence) |
|
|
Term
| What does DNA polymerase require the presence of? |
|
Definition
| DNA and all four deoxyribonucleotide trphosphates (dTTP, dATP, dCTP, and dGTP) |
|
|
Term
| What are the template requirements of DNA polymerase? |
|
Definition
| can only add nucleotides to the 3' hydroxyl terminus of an existing strand and the strand that provides the 3' OH terminus is called the primer |
|
|
Term
| In what direction can DNA polymerase synthesize new DNA in? |
|
Definition
| 5' to 3' direction but DNA polymerase moves 3' to 5' |
|
|
Term
| What is the result of two strands being synthesized by a different sequence of events? |
|
Definition
| they grow in opposite directions, one growing towards the replication fork an the other growing away from the fork. |
|
|
Term
| How are the 2 strands assembled? |
|
Definition
| One strand is assembled in a continuous fashion while the other is as fragments that are joined together enzymatically. |
|
|
Term
| What is the leading strand? |
|
Definition
| the strand that is synthesized continuously |
|
|
Term
| What is the lagging strand? |
|
Definition
| the strand that is synthesized discontinually. |
|
|
Term
| What are okazaki fragments? |
|
Definition
| relatively short fragments of DNA created on the lagging strand during DNA replication |
|
|
Term
| What is the length of Okazaki fragments in bacteria? |
|
Definition
| 1000-2000 nucleotides in length |
|
|
Term
| What is the length of the Okazaki fragments in eukaryotes? |
|
Definition
| less than 200 nucleotides |
|
|
Term
| What joins the Okazaki fragments into a continuous strand? |
|
Definition
|
|
Term
| Unwinding and separation of strands require two types of proteins that bind to DNA, what are they? |
|
Definition
1. Helicase, a DNA unwinding enzyme
2. single-stranded DNA binding protein. (SSB) |
|
|
Term
| How do DNA polymerase travel? |
|
Definition
| together even though they are moving towards opposite ends of their respective templates |
|
|
Term
| What is the enzyme that synthesizes DNA in E. coli? |
|
Definition
|
|
Term
|
Definition
| contains 10 different subunits organized into several distinct compartments. |
|
|
Term
| What is DNA polymerase I involved in? |
|
Definition
| DNA repaair where damaged sections of the DNa are corrected. |
|
|
Term
| What is the Klenow Fragment? |
|
Definition
|
|
Term
| In Eukaryotes where does replication begin? |
|
Definition
| In many locations, however in E. Coli it begins in only one place |
|
|
Term
| WHat is a major component of the Eukaryotic replication fork? |
|
Definition
| activities that occur at the replication forks are similar |
|
|
Term
| What are the proteins in the tool kit? |
|
Definition
| helicases, single-stranded DNA binding proteins, DNA polymerasr and DNA ligase |
|
|
Term
| What is the nuclear lamina? |
|
Definition
| a meshwork within the nucleus that adds mechanical supprt , allows movement of molecules across the envelope and can interact with chromatin |
|
|
Term
| What is the nuclear matrix? |
|
Definition
| it is the protein containing fibrillar network |
|
|
Term
| Replication occurs at specific sites called what? |
|
Definition
| replication foci. There are 50-250 sires in the cell nucleus |
|
|
Term
| DNA Repair refers to what |
|
Definition
| a collection od processes by which a cell identifies and corrects damage to the DNA molecule |
|
|
Term
| What is the DNA rate of repair dependent upon? |
|
Definition
| cell type, age of the cell, extracelluar environment |
|
|
Term
| What are the three states that a cell that has incurred a great deal of damage enter? |
|
Definition
1. an irreversable state of dormancy known as senescence
2. cell suicide, also known as apoptosis or programmed cell death
3. unregulated cell division which can lead to the formation of a tumor that is cancerous |
|
|
Term
| Some case damamges can be repaired directly but most require that .. |
|
Definition
| a damaged section of the DNA be excised , selectively removed |
|
|
Term
| What are the DNA repair mechanisms |
|
Definition
Nucleotide excision repair
Base excision repair
mismatch repair
Double stranded breakage repair |
|
|
Term
| Nucleotide excision repair |
|
Definition
| cut and patch mechanism that removes a variety of lesions |
|
|
Term
|
Definition
| remove altered nucleotides |
|
|
Term
|
Definition
| remove mismatched bases incorporated by DNA polymerase and escaped by proofreading mechanisms |
|
|
Term
| Double-strand breakage repair |
|
Definition
| DNA breaks due to radiation |
|
|
Term
|
Definition
| a slower less efficient pathway that corrects DNA strands in the remainder of the genome |
|
|
Term
| Base excition repair function |
|
Definition
| removes altered nucloetides generated by reactive chemicals present in the diet or produced by metabolism |
|
|
Term
|
Definition
| a number of DNA glycosylasees have been identified each more or less specific to a particular type of altered base. |
|
|
Term
| What does a mismatch base pair cause? |
|
Definition
| a distortion in the geometry of the double helix that can be recognized by a repair enzyme. |
|
|
Term
| What is the repair of damaged DNA due to? |
|
Definition
| X-rays, gamma rays, and other radiation |
|
|
Term
| What can radiation break? |
|
Definition
| both strands of the double helix |
|
|
Term
| What are the two pathways of double stranded breakage repair? |
|
Definition
| nonhomologous end joining and homologous recombination |
|
|
Term
| the cell cycle or cell division cycle is what? |
|
Definition
| the series of events that takes place in a cell leading to its division and duplication |
|
|
Term
| How does the cell cycle occur with cells that do not have a nucleus? |
|
Definition
|
|
Term
| What is the cell division cycle referred to as in cells that do have a nucleus? |
|
Definition
|
|
Term
|
Definition
| Another type of cell division where a cell is permanently transformed into a gamete and cannot divide again until fertilization |
|
|
Term
| What are the two major phases into which the eukaryotis cell cylcle can be divided into? |
|
Definition
| M phase and Interphase which is the largest phase. |
|
|
Term
|
Definition
| includes mitosis during which duplicated chromosomes are separated into two nuclei and cytokinesis during which the entire cell divides into two daughter cells |
|
|
Term
|
Definition
| the period between cell divisions. It is the time when the cell grows and engages in diverse metabolic activities. |
|
|
Term
|
Definition
| the first phase within interphase, the growth phase |
|
|
Term
|
Definition
| second phase within Interphase. Begins when DNA synthesis begins and is completed when all of the chromosomes have been replicated |
|
|
Term
|
Definition
| third phase in interphase, significant protein synthesis ocurs in this phaseand it lasts until the cell enters mitosis. |
|
|
Term
| What during the G2 phase can prevent the cell from undergoing mitosis |
|
Definition
| inhibition of protein synthesis |
|
|
Term
| What is the cell cycle focused on? |
|
Definition
| initiation of DNA replication and initialtion of mitosis |
|
|
Term
| The cytoplasm contains factors that regulate what? |
|
Definition
|
|
Term
| What is a Maturation Promoting Factor (MPF)? |
|
Definition
| the activation of a protein kinase which triggers entry into the M phase. stimulates entry inyo mitosis as seen by compaction of DNA |
|
|
Term
|
Definition
| Part of the MPF complex which regulates its activity |
|
|
Term
|
Definition
| are not only involved in M phase and orchestrate activities throughout the cell cycle |
|
|
Term
| What are the brakes and accelerators that operate in combination with one another? |
|
Definition
| are cyclin bonding, Cdk phosphorylation/dephosphorylation, Cdk inhibitors, and controlled proteolysis, and subcellular |
|
|
Term
| What accumulates in the nucleus at the start of mitosis? |
|
Definition
|
|
Term
| Chromatin is dispersed in interphase for what |
|
Definition
| transcription and replication |
|
|
Term
| DNa replication only happens in S phase. What else is replicated in S phase |
|
Definition
| histones and centrioles in preparation for mitosis |
|
|
Term
| Chromatin condenses into chromatids and forms mitotic chromosomes in mitosis and what does this result in? |
|
Definition
| Since it is condensed ranscription and replication stop. There is also little or no translation |
|
|
Term
|
Definition
"sensors" detect DNA damage or cellular abnormalities
the cell cycle is arrested, stalling progresion to the next step
During this delay , DNA is repaired or the cell defect is corrected |
|
|
Term
| Cdk inhibitor proteins can act as what to stop the cell from progressing to the next step |
|
Definition
|
|
Term
|
Definition
| Number of complete sets of chromosomes in a biological cell |
|
|
Term
|
Definition
| number of chromosomes in a gamete of an individual |
|
|
Term
|
Definition
| the number of chromosomes in a single non-homolgous set |
|
|
Term
|
Definition
| single set og genetic information. Single genome |
|
|
Term
|
Definition
| two full sets of genetic information. Two copies of the genome |
|
|
Term
|
Definition
| Many sets of genetic information. MAny genomic sopies |
|
|
Term
| Chromosomes vary throughout |
|
Definition
|
|
Term
| In G1 (in humans) there are 22 autosomes and 1 sex chromosome but how many pieces of disperse chromatin are there |
|
Definition
| 46 pieces because we are diploid and they are all linear and double stranded DNA |
|
|
Term
| In S Each piece of disperse chromatin does what? |
|
Definition
| doubles to 92 pieces of disperse chromatin in S phase/ The nuclues is still diploid |
|
|
Term
|
Definition
| the 92 pieces of disperse G2 chromatin condense in mitosis to form 92 chromatids |
|
|
Term
| In metaphase all pairs are aligned where |
|
Definition
| at the middle of the cell |
|
|
Term
|
Definition
|
|
Term
|
Definition
| the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei |
|
|
Term
| Mitosis is immediately followed by what? |
|
Definition
|
|
Term
| Mitosis and cytokinesis together form what |
|
Definition
|
|
Term
|
Definition
| the nuclei, cytoplasm, organelles and cell membrane into 2 cells |
|
|
Term
| What are the 5 stages of mitosis |
|
Definition
| prophase, prometaphase, metaphase, anaphase, and telophase |
|
|
Term
| What are the three important things that happen in prophase? |
|
Definition
1. Chromosomes condense
2. Mitotic spindle forms
3. Nuclear envelope breaks down. This occurs at the end of prophase |
|
|
Term
|
Definition
| helps keep the two pieces of chromatin together after S-phase, through G2 and into the beginning of prophase |
|
|
Term
|
Definition
| condensin, its involved in the formation of mitotic chromosomes |
|
|
Term
| Sister chromatids are held together by |
|
Definition
|
|
Term
|
Definition
| supercoil DNA and organize the supercoiled loops into larger coils |
|
|
Term
| What helps to hold the DNA in the mitotic chromosomes? |
|
Definition
| A scaffold of cohesin, condensin, and other proteins |
|
|
Term
| Where do centromeres occur? |
|
Definition
| at a primary constriction on chromosomes and serve as the binding sight for proteins |
|
|
Term
|
Definition
| the sight where chromosomes to the microtubules of the mitotic spindle |
|
|
Term
| when does the kinetochore assemble on the centromere |
|
Definition
|
|
Term
|
Definition
| contains a variety of proteins attached to the centromeric heterochromatin |
|
|
Term
|
Definition
| binds motor proteins involved in chromosome movement |
|
|
Term
| In what direction does dynein move in the kinetochore |
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Definition
| toward the minus end of the microtubule |
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Term
| What serves as the nuceation site (MTOC) for cytoplasmic microtubules |
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Definition
| pericentriolar material surrounding centrioles |
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Term
| How are the microtubules arranged around each centromere? |
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Definition
|
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Term
| What promotes the dissassembly of the nuclear lamina |
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Definition
| phosphorylation of lamins by miotic Cdk |
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Term
| How can you tell you're in prophase? |
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Definition
1. Mitotic chromosomes are seen but they arent clustered near the middle.
2. Microtubules form the mitotic spindle have not made contact with any chromosomes |
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Term
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Definition
1. Plus ends of Chromosomal MTs start to capture mitotic chromosomes at their kinetochors
2. Mitotic chromosomes begin to oscillate and end up near the spindle equator at the end of prometaphase
3. Sister chromatids end up in amphitellic orientation Each faces opposite poles |
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Term
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Definition
| holds sisters chromatids together at the centromere |
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Term
|
Definition
| is a protein complex that is attached to the centromere |
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Term
|
Definition
| Eminate from centrosome into cytoplasm to anchor and position the aster |
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Term
|
Definition
| Connect form pericentriolar material of centrosome to kinetochores |
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Term
|
Definition
| Extend from centrosome to equator but interact with other polar Microtubules instead of chromosomes |
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Term
| Three main forces for movement in premetaphase |
|
Definition
1. Dynein and kinesin-like motors on the kinetochore corona fibers grab th MT and position it
2. Polymerization and depolymerization of tubulin to lengthen and shorten MTs
3. "cargo and rail" action of motor proteins on MTs to postioin chromosomes and poles |
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|
Term
| The kinetochore is atached to the |
|
Definition
| centromere and corona fibers stick out from it |
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Term
|
Definition
| movement of MT to the poles |
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Term
|
Definition
| each one of the two sister chromatids face oppostie poles |
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Term
|
Definition
| equator of the mitotis spoindle |
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Term
| Colchicine and colcemid produce what |
|
Definition
| metaphase chromosomes because it stops them from being pulled a[arat in anaphase |
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Term
| How can you tell you are in metaphase |
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Definition
| Chromosomes are aligned along the metaphase plte attached by chromosomal MT to both poles |
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Term
|
Definition
1. centromeres split and chromatids separate
2. Chromosomes move to oppposite spindle poles
3. Spindle poles move farther apart |
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Term
| How do you know you're in Anaphase |
|
Definition
| Sister chromatids have com apart but they aren't very close to the poles yet |
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Term
| What happens in Anaphase A |
|
Definition
| Chromatids move towards the poles by mitotic shortening |
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Term
|
Definition
|
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Term
|
Definition
| assures that all chromosomes reach the spindle equator before anaphase begins |
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Term
| During telophase the daughter cells return to interpahse |
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Definition
| Nuclear envelopes of the two nuclei are reassembled and chromosomes become dispersed |
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Term
|
Definition
separated daughter chromosomes arrive at the poles and the chromosomal MTs disappear
a new nuclear envelope reforms around each group of daughter chromosomes |
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Term
| How do you know that you are in telophase |
|
Definition
| Chromatin becomes disperse and clustered near the poles. No mitotic chromosomes vcan be seen |
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