Term
| Chromosome Theory of Inheritance |
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Definition
States that inheritance patterns may be explained by assuming that genes are located in specific sites on chromosomes
Genes have specific loci on chromo.
Chromo. undergo segregation and independent assortment |
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Term
| Similarities between Mendel's factors and chromosomes |
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Definition
Both are present in pairs in diploid cells
Homo. chromo. separate and alleles segregate
Fertilization restores both paired conditions |
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Term
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Definition
Discovered sex linkage
Studied fruit fly eyes-- white eyes only occurred in males |
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Term
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Definition
Specific traits are located on X-Chromo. ONLY
XX needs both recessive alleles to exhibit phenotype
XY has only one X to exhibit (homozygous) |
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Term
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Definition
Genes on the same chromo. are linked because they're inherited together
Crossing over and Synapsis create other recombinants |
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Term
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Definition
Contain genes unrelated to sex
(M) give trait to daughters
(F) give trait to both and are usually carriers
Disorders are usually recessive |
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Term
| Recessive, sex-linked diseases |
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Definition
Colorblindness
Duchenne Muscular Dystrophy
Hemophilia |
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Term
| Inactivation of X in females |
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Definition
Each female cell has XX-- one is active and the other is inactive (Barr Body)
Random choice which X will be expressed--determined by methylation of cytosine on Barr Body |
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Term
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Definition
Chromo. don't move apart
Meiosis I--homo. pairs don't separate (stuck in synapsis) and produces 4 non-normal gametes
Meiosis II--sisters don't dissociate, still attached by centromere and produces 2 normal and 2 abnormal gametes |
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Term
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Definition
Abnormal number of chromo.
3 of one chromo. (Trisomy)
1 of a chromo. (Monosomy)
Happens in meiosis |
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Term
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Definition
| More than 2 complete sets of chromo. |
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Term
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Definition
Lethal
Down's Syndrome (only viable AA)--3 copies of chromo. 21, several physical diff., nondisjunction during meiosis I, frequency increases with age of mother |
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Term
| Sex Chromosome Aneuploidy |
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Definition
Turner Syndrome (XO)--woman (monosomy)
Klinefelter Syndrome (XXY)--mostly male
Poly-X Syndrome (XXX or XXXX)--female only
Jacob's Syndrome (XYY)--male |
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Term
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Definition
Lose part of the chromo.
Homo. chromo. still has correct genes
Large deletion is lethal |
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Term
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Definition
Deleted fragment will attach to homo. pair to create a repeat
Creates double the amount of needed protein |
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Term
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Definition
Segment attaches in the opposite direction--flipped
Translocation--2 diff. chromo. exchange fragments
Reciprocal T--both chromo receive a segment
Nonreciprocal T--deleted piece will insert into a diff. chromo.
One-way Transfer--original doesn't receive any in return (common in cancer) |
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Term
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Definition
Worked with streptococcus pneumoniae--smooth bacteria w/ capsule is pathogenic, rough bacteria w/o capsule is nonpathogenic
Heat-killed smooth and mixed with live rough
Rough turned pathogenic in mice
Proved smooth heat-killed cells transformed rough cells |
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Term
| Avery, McCarty, and McLeod |
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Definition
Purified components of bacteria and mixed with rough strains and infected mice
Found transforming product to be DNA
Proved DNA was genetic material |
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Term
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Definition
E. Coli vs. Virus (phage)
Grew 2 batches of phage and let it infect bacteria
Blended cells to dissociate phage from cells
Centrifuged "blended" contents
Looked for location of radioactivity
Learned DNA entered cell as the genetic material |
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Term
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Definition
Analyzed nitrogenous base composition
DNA composition and ratio of NBs varies from species to species
Ratio A to T and G to C the same in all species |
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Term
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Definition
| X-ray diffraction of DNA showed double helix |
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Term
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Definition
Built structure of DNA by trial and error
Hydrophobic core (NBs) on inside
Bases paired by hydrogen bonding
Outside--polar ribosesugars, hydrophilic
Inside--nonpolar core, hydrophobic |
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Term
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Definition
Gray Wheel--de-oxy ribosesugar
Yellow Wheel--de-oxy ribosesugar on compliment strand (replication)
Orange Wheel--ribose sugar w/ OH group (transcription)
Purple rod w/ blue attachment--phosphate
Orange rod--double hydrogen bond
Brown rod--triple hydrogen bond |
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Term
| Conservative DNA replication |
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Definition
| One parent DNA, one new DNA |
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Term
| Semiconservative DNA replication |
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Definition
| One strand from parent and other new (just replicated) strand |
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Term
| Dispersive DNA replication |
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Definition
| 4 strands have a mixture of old and new |
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Term
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Definition
Grew E. coli w/ Nitrogen and put into DNA
Centrifuged so heavier DNA came out lower in tube
Data was consistent w/ semiconservative DNA replication |
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Term
| Origin of Replication in Bacteria |
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Definition
Replicates in 30 min.
Protein recognizes specific origin sequence
Replication bubble proceeds in both directions until both reach the terminus (end)
Each origin is pulled to opposite poles
Cell divides by binary fission |
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Term
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Definition
Split in 2 DNA strands at ends of bubble
Multiple bubbles fuse as DNA is copied
Bidirectional |
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Term
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Definition
Complex of many subunits that synthesizes DNA
Adds nucleotides to growing chain
Energy comes from dehydration synthesis (loss of water) |
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Term
| DNA is complimentary and antiparallel |
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Definition
Each nucleotide has a complimentary base pair
Both strands run in opposite directions and has a 5' and 3' end |
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Term
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Definition
3' end matches with 5' end of new DNA
DNA unzips more and the strand keeps adding nucleotides |
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Term
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Definition
Replicates away from the fork toward 3' end
Replicates short sequences of DNA at a time called Okazaki fragments |
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Term
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Definition
RNA primer added to start replication
DNA polymerase can't initiate synthesis w/o primer
RNase chews RNA and replaces it w/ a diff. part of the DNA polymerase complex, then sealed by ligase
Each Okazaki fragment is primed |
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Term
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Definition
| Seals together Okazaki fragments by bonding complimentary nucleotides |
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Term
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Definition
| Unwinds DNA by breaking H bonds to release single strands |
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Term
| Single-strand DNA binding protein |
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Definition
| Hold strands of DNA apart so the bonds don't reform |
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Term
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Definition
Protect genes at end of chromo. from being lost when RNA polymerase falls off
"junk" |
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Term
| Central Dogma of Molecular Biology |
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Definition
DNA -transcription-> RNA -translation-> Proteins
TX--genotype
TL--phenotype |
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Term
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Definition
Different sugar backbone (deoxy vs. oxy)
RNA has uracil, not thymine
RNA is single-stranded |
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Term
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Definition
4 nucleotide bases
Transcribed in nucleus by RNA polymerase (to mRNA) |
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Term
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Definition
Sequence of amino acids
Translated in cytoplasm by ribosomes (from mRNA)
Protein synthesis is most important part of tx/tl |
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Term
| Differences in gene expression |
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Definition
Different RNA polymerases
Different tx factors to assist in DNA recognition by RNA polymerase
TX termination
Diff. ribosomal components
RNA processing and targeting
Regulation of gene expression |
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Term
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Definition
No nucleus
RNA doesn't leave the nucleus
TX and TL occur at the same time |
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Term
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Definition
Compartmentalization (nucleus and cytoplasm)
mRNA is modified as it exits the nucleus (RNA processing) |
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Term
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Definition
Complex of many proteins that work together to tx DNA
Bacteria: one RNA polymerase
Eukaryotes: 3 polymerase complexes
Pries apart DNA and adds nucleotides to the mRNA as it copies one strand of DNA
New RNA interacts w/ DNA as it is tx, but H bonds are broken as it leaves the RNA polymerase
Adds nucleotides to 3' end |
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Term
| Transcription Initiation (TX) |
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Definition
Gets RNA polymerase to necessary strand of DNA
Upstream--part of gene before TATA box
Downstream--everything after TATA box
Promoter--specific sequence upstream of TATA, lets RNA polymerase know where to bind
TX factors--accessory proteins that bind to promoter
DNA unwinds and polymerase tx (adds nucleotides) DNA at TATA |
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Term
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Definition
Moving of RNA polymerase through DNA strand; addition of nucleotides
Polymerase II moves downstream, unwinding and elongating template strand of DNA
Many RNA polymerases on same gene=many tx sites=high protein product
DNA closes back behind RNA polymerase |
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Term
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Definition
Termination sequence in DNA that tells pol II to stop tx
RNA structures form and cause pol to fall off |
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Term
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Definition
Only in eukaryotes
Required for mRNA to become functional and exit nucleus
Protects RNA so nucleases don't chop it up
5' cap
3' (poly-A) tail
Splicing of introns and joining of exons
Fully processed RNA can leave the nucleus fo tl now |
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Term
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Definition
Same 20 aa make up all proteins in all living organisms
3 nucleotide bases per aa=64 combinations
Codon--3 RNA nucleotides per aa
3 stop codons--UAA, UGA, UAG (terminate tl)
1 start codon--AUG
Substitutions can have no effect (silent), little effect (missense), or create a stop codon or nonfunctional protein (nonsense) |
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Term
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Definition
Happens in cytoplasm
All RNA made in nucleus and then shipped to cytoplasm |
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Term
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Definition
Comes from tx
Becomes tl and carries message from DNA |
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Term
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Definition
Carries aa
Anticodon binds to mRNA codon
3' end attaches to aa
most tRNA specific to one codon
T shape w/ anticodon on bottom; carries aa on top |
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Term
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Definition
Structural component of ribosome
Both tRNA and rRNA are both tx from DNA but aren't tl |
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Term
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Definition
Made up of rRNA and ribosomal proteins
Proteins on outside, RNA on inside
Some RNA act as enzymes during tl
Large subunit--2 binding sites for tRNA
Small subunit--binding site for mRNA
Subunits only connected during tl |
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Term
| Large Subunit of Ribosome (TL) |
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Definition
Structure=function
A site--binding site for tRNA
P site--binding site for growing peptide
E site--binding site for used tRNA |
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Term
| Translation Initiation (TL) |
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Definition
Small subunit bind to mRNA upstream of codon
First tRNA binds to AUG
Larger subunit attaches
Accessory proteins bring everything together |
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Term
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Definition
Codon recognition--tRNA ushered in by elongation factor
Peptide bond formation--aa in A site bonded to polypeptide in P site by ribozyme in large subunit
Translocation--move tRNA from A to P site |
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Term
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Definition
Release factor binds to stop codon in A site
Adds water to end to cut off polypeptide (hydrolysis) |
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Term
| Protein Structure and Function |
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Definition
Protein now needs to modify to become functional
4 levels of protein structure (1, 2, 3, 4)
Post-translational modification:
Chemical modification (adds OH, sugar, lipid, & phos.)
Cleavage by enzymes (into smaller peptides)
Joining of several polypeptides in 4 structure |
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Term
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Definition
DNA bound w/ proteins in a complex
Structure of chromosomes is based on diff. levels of packing DNA |
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Term
| Structure of chromosomes (regulation) |
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Definition
Histones--proteins that wind up DNA to make it fit into a smaller area (nucleosome)
30 nm fiber--coils of nucleosomes
Looped domains--fibers looped around scaffold protein |
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Term
| Differential expression (regulation) |
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Definition
Some cells express certain proteins while others don't
All cells have same DNA but don't express same proteins |
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Term
| Histone modification (regulation) |
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Definition
Unwinding of histones for use
Acetylation--causes uncoiling of fibers (for tx)
Methylation--condenses fibers to make them tighter |
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Term
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Definition
Enhancers--DNA sequences far away from TATA
Activators--protein that binds to enhancer region
Repressors--stop transcription
Only certain cells produce the tx factors necessary for tx to occur |
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Term
| Post-transcriptional regulation |
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Definition
RNA processing--need all 3 steps
mRNA degradation--determines how much protein is made
TL initiation--no ribosome interaction, to tl
Protein processing/modification--it not in correct structure, protein is useless |
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Term
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Definition
Regulation during RNA processing
One gene can make diff. proteins depending on the exons
Cells choose which exons are needed |
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Term
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Definition
The time an mRNA is in the cell will determine how much of a protein is tl and produced
Path of mRNA breakdown
Regulatory elements are found in 5' and 3' ends |
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Term
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Definition
Degrades nonfunctional or old proteins
Chews up proteins into aa that can be reused |
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Term
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Definition
Ways to increase diversity other than random mutation
Transformation--uptake of DNA from the environment or exogenous source
Transduction--phage DNA enters bacteria (Lytic or lysogenic, takes host DNA w/ it)
Transposons--"jumping genes"--mobile genetic elements that move w/in the chromo. or to another cell
Conjugation--"bacterial mating"--use pilli to transfer genes |
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Term
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Definition
Coordinately controlled genes in a pathway
Operator--specific sequence that allows polymerase to bind
Repressor--stops tx by hiding operator from RNA polymerase
Promoter
Genes
Polycistronic--have one long gene w/ multiple operons |
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Term
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Definition
Turns on only when necessary
Needed to regulate gene expression
Needed when glucose is low and needed to break down lactose to get energy
3 genes in operon (lacZ, lacY, lacA) |
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Term
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Definition
Aggregates of protein and nucleic acid
Some have an outer membrane (envelope)
DNA--double or single stranded
RNA--need special proteins encoded by virus to replicate genome |
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Term
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Definition
Attaches to host cell
Inserts DNA and inner contents
Uses host machinery to replicate proteins and genetic material
Self-assembles into new particle
Exits the cell by lysis (bacterial) or budding (eukaryotic)
May insert itself into the host genome (lysogeny) |
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Term
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Definition
| Causes cell to burst when leaving |
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Term
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Definition
| Remains in the host cell until conditions become appropriate |
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