Term
| Four characteristics of a Gene |
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Definition
Characteristics of a Gene (PARC)
Correlation with a trait/phenotype
Able to replicate itself or copy itself
3) Relatively Stable
4) Mutation is possible to allow for variation —-> Alleles (Different forms of the same gene) |
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Term
What are the purines and how many sugars do they have?
What are the pyrimidines and how many sugars do they have? |
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Definition
Pyrimidines (CandT and CandU) (1 sugar)
Purines (AandG) (2 sugars) |
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Term
Which Oxygen is missing on deoxyribose.
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Definition
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Term
| 3 predictions of Watson and Crick |
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Definition
DNA could be genetic material.
a) Turns to the right. (partially correct) (Right handed helix) Base pairs are perpendicular to the back bone and there are 36 degrees between base pairs. Thus, 10 base pairs per turn. Called B-DNA. A, C, D DNA are all right handed but differ in the other criteria. Not all types of DNA are right handed though.
How might replication occur? We can open up strand without breaking covalent bonds. Can break hydrogen bonds. Each strand can serve as a template for making it’s complement. MOST IMPORTANT PREDICTION |
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Term
| Promoter in Prokaryotes consists of what? |
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Definition
| Binding Region -35 (TTGACA) and Pribnow Box -10 (TATAAT) |
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Term
| Promoter in Eukaryotes consists of what? |
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Definition
| GC Box -110, CAAT Box -70-80 TATA BOX -25 |
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Term
| Is the 1st rNTP synthesized a purine or pyrimidine? |
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Definition
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Term
| What joins amino acids and tRNA? |
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Definition
| aminoacyl tRNA synthetases |
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Term
| allows for ribosome binding to mRNA. |
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Definition
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Term
| put a formyl group onto the methionine that binds to AUG. |
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Definition
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Term
| Where growing strand of amino acids are. |
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Definition
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Term
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Definition
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Term
| start codon position in eukaryotes. Certain set of conserved nucleotides surrounding the AUG that signal it is actually a start codon and not methionine. |
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Definition
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Term
| _________ won’t translate additional genes after a stop codon has been reached, even if they are ok. ________ have the ability to translate more than one gene on mRNA. |
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Definition
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Term
| What were the conclusions of each experiment performed in this unit? |
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Definition
Meselson and Stahl- proved semiconservative model via N14 and N15
Boveri, Boveri, and Sutton- drosophila determined chromosomes are the genetic materials.
Grffith- streptococcus pneumoniae, proved genetic transformation via heat killed S3
Avery, McCleod, Mccarty- showed that nucleic acid is the genetic material (nucleases)
Hershey and Chase- DNA is genetic material for prokaryotes
TMV- showed that RNA is the primary genetic material for viruses and virus like organisms. |
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Term
| What were the 3 conclusions Watson and Crick reached? How did they reach them? |
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Definition
Double Stranded Helix- X Ray crystallography
Strands base pair- chargroffs rule of molar ratios of nucleotides and pH and temperature experiments.
Antiparallel Strands- 5' nearest neighbor (Ball and Stick Model) |
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Term
| What does spleen phosphodiesterase do? |
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Definition
| cleaves bond between a nucleotide and the 5’ radioactive phosphate. |
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Term
| What are the things that DNA replication requires? |
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Definition
1) Place to start
2) Way to separate two strands
3) Way to keep the strands apart
4) Appropriate cell conditions (stuff)
5) Something to do replication |
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Term
| How are the requirements for DNA replication met? |
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Definition
1) Origin of replication (dependent on DNA molecule, thus is unique. Or could be multiple origins)
2) Helicases- unwind the strands
3) Single strand binding proteins (SSB’s)
4) Nucleotides,
5) DNA polymerase(s) |
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Term
| Draw each model of DNA replication |
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Definition
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Term
| Where does DNA polymerase catalyze the reaction for adding nucleotides? |
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Definition
| at the 3’ end containing OH. |
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Term
| Why is primase necessary, what process is it necessary in? |
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Definition
| DNA Polymerase catalyzes the reaction at the 3’ end containing OH. No area exists originally in available replicable DNA. Thus, you need an enzyme to make that area. Primase does this (Which is an RNA polymerase). Does not require a preexisting chain to covalently bond to. |
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Term
| What are plasmids? How do they replicate? |
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Definition
| a replicon that exists separate from the chromosome. (Never a part of another chromosome). Uses rolling circle replication to replicate itself. Nick is made on one strand opening the 3’ and 5’ ends. The 3’ OH is the origin of replication for DNA polymerase to come in and add nucleotides using the inner circle as the template strand. The 5’ growing strand must be displaced by DNA polymerase. The 3’ end (1st step) does not require a primer, the 5’ end does require a primer (2nd step). Primer is eventually removed and nucleotides are sealed with ligase. |
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Term
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Definition
| a replicon that can exist as a plasmid or as part of another replicon (such as a chromosome) |
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Term
| What are the steps of the RecA Homologous Chromsome Recombination |
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Definition
Brings outside DNA in
Degrades it while leaving one of the strands intact
Uses present DNA to find match with foreign DNA.
Base pairing occurs but some parts of each strand will be left unpaired.
The two recently paired strands are not complementary and don’t pair properly leading to mismatches.
Corrects possible mutations by examining differences between homologous chromosomes.
Without any mismatch repair, you will get 50% R2 and 50% S3 offspring.
With mismatch repair, you can:
If S3 strand is corrected and replaced, will get 100% R2
IF R2 strand is corrected and replaced, will get 100% S3. |
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Term
| What are the steps of initiation of transcription in prokaryotes? |
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Definition
1) Pribnow box is recognized by Sigma.
2) Holoenzyme binds -35
3) DNA gets unwound by RNA Polymerase
4) RNA polymerase keeps the strands unwound.
5) 1st rNTP is a purine
6) Form a covalent bond—> dinucleotide
7)Several aborted attempts leading to short RNAs
8) Sigma leaves and core enzyme can proceed at its regular speed. |
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Term
| Describe the components of RNA polymerase. |
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Definition
| Is holoenzyme that is composed of core enzyme and sigma factor. Alpha2BetaBeta is core and sigma factor is simply sigma. |
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Term
| Where does RNA polymerase bind in prokaryotes? |
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Definition
| (Recognizes promoter, called Pribnow box found at -10) RNA polymerase binds further upstream at the TTGACA sequence (-35) |
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Term
| Differentiate between rho dependent and rho independent. |
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Definition
Rho Dependent- NusA catches stem and loop structure and stops it momentarily. Rho , at the 5’ end catches up to RNA polymerase and stop its movement.
Rho independent- Stem and Loop Made up of G’s and C that are triple H bonded, but RNA polymerase is attached at weaker basic pairs of U to A. Nus A catches G and C stem and loop and won’t release, causing the RNA polymerase to detach. |
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Term
| What did Niremberg and Matthei do? |
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Definition
Niremberg and Matthei made use of synthetic RNA. Couldn’t specify order of nucleotides but could determine what went into making the RNA.
Steps Taken to Figure Out code
RNAs made only of A’s, then asked what protein’s would they get. RNAs made only of G’s, C’s, U’s as well and asked what proteins would they get.
2) RNA’s with 5 times as many A’s as Cs. (5:1). Then asked what would be the most common codon. (AAA is most common, CCC is lease common, two As and a C, and Two C’s and one A. Two As and C was then next most common and Two C’s and one A was next.
3) Asked if the code was overlapping or not. |
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Term
| What are the amino acids we need to know? |
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Definition
AUG= Methionine (Start)
UAG= no amino acid, (STOP)
UAA= no amino acid, (STOP)
UGA= no amino acid, (STOP) |
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Term
| What are problems with an overlapping code? |
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Definition
1) Technically Difficult
2) There is only 3 possible amino acids that can come after Methionine and one is a stop.
3) Mistakes in nonoverlapping messes up three amino acids in a complete overlapping code.
4) Amino acid order is independent of previous amino acid. With overlapping, only certain amino acids can follow another amino acid. |
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Term
| What is the function of each type of RNA? |
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Definition
mRNA- messenger RNA- direct correlation between order of codons in mRNA and order of amino acids in proteins.
ribosomal RNA (rRNA)- provides structure to the ribosome (like human skeleton but for ribosome). Some catalytic properties
tRNA (transfer RNA)- adaptor for protein synthesis. |
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Term
| What are the three main elongation factors? |
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Definition
| Elongation Factors- 1) check match in A-site. 2) Covalent bond has to be formed between fMet. Peptidyl synthetase RXN. 3) G factor + GtP hydrolysis that allows ribosome to move one codon along the mRNA. |
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