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Definition
| atoms of an element that have different numbers of neutrons. Some isotopes with extra neutrons are radioactive because the extra neutrons make the nucleus unstable. Isotopes are useful in tracing chemical reactions in plants and animals. |
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Definition
| of two or more atoms joined by chemical bonds |
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| contain two or more elements |
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Definition
| Form between atoms that share electrons; stronger than ionic bonds. |
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| Carbon why is it special? |
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Definition
| has 4 electrons to share; sometimes it shares two electrons with an oxygen atom or another carbon atom; other times each of its electrons is shared with a different atom. Carbon can form many different compounds. |
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Definition
| The partial negative charge on one molecule is attracted to the partial positive charge on another molecule. DIFFERENT CHARGES DUE TO SIZES OF ATOMS |
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| Consequences of polarity of water molecules and hydrogen bonding |
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Definition
| Highly effective solvent; Cohesion going up the trunk of trees; high specific heat, evaporates leaves & cools down; Highest density at 4ºC, ice expands and allows water to stay fairly constant underneath |
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Definition
| Carbohydrates, Lipids, Protiens, Nucelic acids |
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Term
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Definition
| cellulose, starch. 1C:2H:1O, Starch-energy, bonds are broken easily so energy can be obtained. cellulose are resistant to breakdown because alternate glucose subunits are flipped over, so cellulose is used for structural support. both made by glucose. |
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| fats, oils, waxes, phospholipds. Carbon, Hydrogen, Oxygen, phorphorus in phospholipds. Fats and oils= made from glycerol and fatty acids that are long chains of CH2 groups. Energy storage in seeds and animals. fats=solid at room temperture, saturated, oils=unsaturated (double bonds btw c atoms) Phospholipids= similar structure to fats but one fatty acid is replaced by a phosphate group. fatty acids are nonpolar and hydrophobic; phosphate groups are polar and hydrophilic= lipid bilayer. Waxes – contain saturated fatty acids and another long chain molecule with OH groups; provide waterproof coating on stems and leaves. |
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Definition
| large molecules composed of 20 different amino acids; carbon, hydrogen, oxygen, nitrogen and sulfur with a central carbon group bonded to a carboxylic acid group (COOH), an amino group (NH2), and a side chain (R); in water, proteins tend to fold so as to expose hydrophilic groups and enclose hydrophobic groups in the interior. joined by peptide bonds. |
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Term
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Definition
| Primary – sequence of amino acids; Secondary – helical or pleated sheet structures maintained by hydrogen bonds; Tertiary – folding of protein with shape maintained by covalent bonds between sulfur atoms; Quaternary – two or more polypeptide chains held together by hydrogen bonds. |
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Definition
| enzyme catalysts, Storage – protein stored in seeds helps new plants to start growth; animals consume these proteins and specifically require certain essential amino acids that they cannot make themselves; |
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Definition
| large molecules composed of many nucleotide subunits. |
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Term
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Definition
| phosphate group; ribose (RNA) or deoxyribose (DNA); and bases – uracil (only RNA), thymine (only DNA), adenine, guanine, cytosine (both RNA and DNA). |
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Term
| how are nucleotides bonded? |
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Definition
| nucleotides in nucleic acids are attached to each other by covalent bonds through their phosphate groups. |
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Term
| G+C=how many bonds? a+t=how many bonds? what type of bonds? |
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Definition
| hydrogen bonds between bases: three bonds between guanine and cytosine and two bonds between adenine and thymine (uracil). |
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Term
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Definition
DNA forms the genetic material in cells and codes for certain amino acids to be put into proteins; a change in DNA (mutation) may cause different amino acids to be put into a protein chain and thereby affect the way the protein folds and how it functions.
b. RNA copies the information in DNA and does the work of protein synthesis.
c. ATP (adenosine triphosphate) is an important nucleotide that functions as an energy carrier; when its phosphate groups are broken, energy is released for cellular activities. |
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Term
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Definition
| all cells come from pre-existing cells Robert hooke=cork |
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Term
| Compound light microscopes |
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Definition
| Light passes through thin specimens that may be alive or stained with dyes to highlight certain features. |
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| Stereo dissecting microscopes |
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Definition
| large thick specimens that light cannot pass through. |
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Definition
| plant cells because chlorophyll and other plant structures are naturally fluorescent. |
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Definition
Scanning – A beam of electrons passes over the surface of a specimen that has been coated with a thin layer of gold, platinum, or palladium; electrons bounce off the specimen and form an image of surface features.
and
Transmission – Specimens are preserved in plastic and extremely thin slices are cut and stained with lead (for lipids and proteins) and/or uranium (for DNA and RNA); electrons pass through the slice but are deflected by the heavy metals to form images of the cell’s components. |
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Term
| Common features of all cells |
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Definition
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Term
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Definition
| Two membranes (nuclear envelope) enclose the nucleus; pores in the membrane allow communication between the nucleus and the rest of the cell. |
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Definition
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Definition
| has ribosomes on surface and synthesizes protiens |
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Definition
| fatty acids and phospholipds that breaks down toxins in the cell |
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Term
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Definition
| CISTERNA; Golgi membrane pinches off to form a vesicle carrying the molecules. |
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Term
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Definition
Microtublues= tubule membrane
Microfilaments=actin
intermediate filaments |
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Definition
chemical energy into movement
Kinase= slow and steady (turtle-->duck-->K!)
Dynein= sliding movement
associated with microtubulin |
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Term
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Definition
Cristae=contain enzymes and other molecules important for energy metabolism
Reproduce by binary fission like bacteria. Believed to be descended from ancient bacteria engulfed by another cell. |
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Definition
| surrounded by single membrane; contain enzymes, one of which is catalase which breaks down hydrogen peroxide, a harmful product of metabolism. |
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Definition
| protect cell; contain cellulose (major structural component of cell walls composed of long cables) and non-cellulose (hemicellulose (binds cellulose fibrils together); pectin (combines with calcium and water to make jelly-like matrix between cells; used to make jam and jelly candy); proteins.) |
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Term
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Definition
Primary and secondary
1. single layer cell wall of growing cells that maintains ability to stretch.
2. laid down inside the primary wall as cells mature; lignin may be added to the walls of water-conducting cells to make them impermeable to water |
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Term
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Definition
| channels running through cell walls connecting the cytoplasm of adjacent cells; channels are lined with cell membrane and contain a strand of ER; can be permanently sealed if cells are damaged. |
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Term
| Chloroplasts (40-50 each cell) |
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Definition
Internal membranes (thylakoids) contain chlorophyll and other molecules important for photosynthesis; watery stroma contiain other enzymes. Ribosomes and small amounts of DNA similar to those in prokaryotes.Reproduce by binary fission like bacteria.
Believed to be descended from ancient cyanobacteria. |
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Definition
Amyloplasts – non-green plastids that store starch.
Chromoplasts – plastids containing carotenoid pigments that color leaves, flowers, and fruits red, orange or yellow. |
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Definition
| large vacuoles characteristic of mature plant cells; important in maintaining turgor pressure; storage area for pigments, acids, sugars, heavy metals, tannins |
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Term
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Definition
enclose cell contents; composed primarily of phospholipids and proteins; important functions
involved in:
1. Communication – receptor proteins in membranes bind to chemical messengers, such as plant hormones, and transmit signals to cytoplasm
2. Transport of dissolved substances – gases and some small molecules pass easily through membranes; larger, charged molecules do not, unless they are transported by proteins.
3. Transport of larger or charged molecules – transport proteins in membranes are specific for certain kinds of molecules and bind with these molecules to move them through the membrane, e.g., membranes of plant root cells transport phosphate and nitrate from the soil into the cells . |
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Term
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Definition
endocytosis & exocytosis
water-osmosis |
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Term
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Definition
histone protiens and dna
each chromosome occurs as a member of a homologous pair of chromosomes.
Each homologous chromosome contains genes for the same traits as the other homologous chromosome; since there are two chromosomes, these cells are diploid.
Some cultivated and wild plants contain four or six chromosomes with similar genes and are called tetraploid or hexaploid. |
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Definition
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Definition
increases in size and synthesizes enzymes, ribosomes, membranes, microtubules and microfilaments.
Nucleus migrates to center of cell and is held in place by a sheet of cytoplasm (phragmosome) containing microtubules and filaments.
Checkpoint at the end of this phase, which may stop the cycle if conditions are not favorable, or may signal beginning of next phase. |
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Term
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Definition
| DNA and Histone replication. |
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Term
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Definition
final phase of rapid protein synthesis, especially of microtubules and filaments; at the end of this phase, DNA starts to condense to form chromosomes.
b. Checkpoint at the end of this phase, which may stop the cycle if conditions are not favorable or if there were mistakes in DNA replication. |
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Term
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Definition
| prophase, metaphase, anaphase, telephase |
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Term
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Definition
1. DNA first appears as threadlike strands and then condenses into chromosomes.
2. Each chromosome has been duplicated and the two identical “daughter” chromosomes (called chromatids) are seen joined together at the centromere.
3. Microtubules appear first in a random arrangement, then they line up along the spindle axis with tubules converging at the poles away from the equator of the spindle (which lies in the same plane as the phragmosome).
4. nuclear membrane begins to break down.
cancer drugs interfere with microtubules! |
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Term
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Definition
Each chromatid develops a protein complex called a kinetochore that attaches to microtubules extending toward one pole; kinetochore of the sister chromatid attaches to microtubules extending to the opposite pole.
Microtubules tug chromatids in opposite directions so they tend to line up along the equator of the cell.
Cohesin proteins hold chromatids together.
taxol |
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Term
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Definition
| Sister chromatids separate at the centromere and move apart towards opposite poles; after separation, chromatids are called daughter chromosomes. |
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Definition
New nuclear envelop forms around the two new sets of chromosomes which uncoil and become less distinct.
Spindle disappears. |
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Term
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Definition
phragmoplast (structure made up of microtubules and microfilaments) forms between 2 daughter nuclei.
secretory vesicles from the Golgi form a cell plate at the center of the cell; it then grows out toward the edges.
cell membrane and new cell wall form. |
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Term
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Definition
| remember: crossing over, in meristematic tissue, gametes, Haploid, nonjisdunction |
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Term
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Definition
pyrimidines= C and T
Purines= G and A |
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Term
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Definition
CHargaff= A=T
watson, crick, franklin= helical |
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Definition
complementary, not identical
Expressed as kilobases (kb, thousands of base pairs); 1 kilobase contains about enough information to code for one average protein. |
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Term
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Definition
| DNA polymerases can reverse themselves and go back to repair damage during replication; DNA repair nucleases can cut out damaged pieces of DNA and then put in the correct bases; DNA ligase connects the repaired section to the main strand. |
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Term
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Definition
MRNA; TRNA; rRNA
base + ribose sugar + phosphate
RNA molecules are usually single stranded but some parts of RNA molecules may be folded to have sections that are double stranded |
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Term
| mRNA synthesis (transcription) |
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Definition
DNA--> RNA
RNA polymerases attach at a promoter region on DNA, open up the DNA double helix, and complementary nucleotides are added.
In eukaryotes, mRNA must be processed before leaving the nucleus.
a. Sequences that do not code for protein (introns) are cut out.
b. A cap is added at one end and a tail containing a series of adenine bases is added at the other end to prevent degradation by RNAses in the cytoplasm. |
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Term
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Definition
| Ribosomes are made of protein and RNA (rRNA); there are two subunits: a smaller one with a binding site for mRNA and a larger one with 3 binding sites for tRNAs. |
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Term
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Definition
One of the free ends of the tRNA has an attachment site for an amino acid; a specific enzyme recognizes the shape of the tRNA and attaches the correct amino acid .
In the loop opposite the free ends, there is a group of 3 bases called the anticodon: these are complementary to the codon for the amino acid that is attached to the tRNA. |
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Term
| Protein Synthesis (Translation) |
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Definition
| Initiation, Elongation, Termination |
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Term
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Definition
An initiator tRNA containing methionine and a mRNA attach to the small ribosomal subunit with the anticodon of the tRNA attaching to the start codon on the mRNA.
The larger ribosomal subunit attaches to the smaller subunit. |
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Term
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Definition
tRNAs carrying their amino acids attach to the ribosome and to the mRNA codons complementary to the tRNA anticodons.
Peptide bonds are formed between the amino acids, and the ribosome moves down the mRNA. |
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Term
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Definition
| At a stop codon, a cytoplasmic protein binds to the mRNA and the ribosomal subunits separate and mRNA and the protein are released. |
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