Molecular Genetics Flashcards
Translocation
a piece of one chromosome breaks off and attaches to another chromosome
Ligase
Ligase glues separate pieces of DNA back together
Gliagase: sounds like glue
DNA Polymerase
Moves in the 5’ to 3’ direction & adds DNA base pairs.
Polymerase: Enzyme that makes DNA polymers (AKA adds DNA together)
DNA sliding clamp
holds down DNA Polymerase
Sliding clamp is going to clamp down on polymerase to keep it bound to DNA
Primase
Places RNA primer for polymerase to latch on to
PRimase, sounds like primer. R in primase stands for RNA
Topoisomerase
Knicks top of DNA strand to prevent super coiling as helicase unzips strand
Topo(f) DNA strand, T=Tension!! (releases tension)
Single-Strand Binding Proteins
Bind to unbound DNA molecules to prevent re-binding
Read the name. Protein that binds to single strand, gets in the way to prevent re-binding
Point Mutations
mutations of one of the three base pairs (at a point in a codon)
Insertion
insert extra base pair and shift reading frame
Deletion: deleted base pair and shift reading frame
Nonsense
mutation causes a stop codon (this is nonsense, please stop!)
Missense
mutation causes different amino acid (missense: missed our mark)
can be conservative or non-conservative
Silent
mutation causes no change in amino acid (silent because cause no effect)
3 sites of making mRNA into a protein?
EPA
Acceptance
Protein building
Exit
Nucleotide
ribose sugar, nitrogenous base, and phosphate group.
Nucleoside
ribose sugar and nitrogenous base.
Methylation of histones
Adds methyl groups, either increasing or decreasing transcription.
Deacetylation of histones
increases positive charges, tightening DNA-histone attractions and decreasing transcription
Acetylation of histones
removes positive charges, relaxing DNA-histone attractions and allowing for more transcription to happen.
bacteria have what shaped DNA
circular
humans have what shaped DNA
linear
Telomeres are ????
noncoding, repeated nucleotide sequences at the ends of linear chromosomes. Prevent further cell division.
Telomerase is an ???
enzyme that extends telomeres to prevent DNA loss
T/F: Prokaryotes do not have membrane-enclosed nuclei, sooo both transcription and translation occur simultaneously in the cytosol.
TRUE!
Lytic cycle
virus takes over host to replicate and does cause harm to the host. The viral particles produced can lyse the host cell to find other hosts to infect.
Lysogenic cycle
virus is considered dormant because it inserts its own genome into the host’s genome and does not harm the host. Each time the host genome undergoes replication, so does the viral genome.
viral replication cycle mneumonic is what
APUSAR
where does transcription occur in prokaryotes?
cytosol!
To regulate the promoter, _____ bind to the operator regions, while activators bind to the ______ sites.
Repressors, promoter
The lac repressor protein is the first way that the lac operon is controlled. This protein is always….? This means the protein is always bound to the _____, _____ transcription.
ON, operator, blocking
If lactose is present, what occurs?
It is converted to allolactose
Allolactose binds directly to the repressor protein and removes it from the operator, allowing transcription to occur!
cAMP and glucose are _____ related.
This means…..
inversely
When glucose is low, cAMP is high
cAMP binds to CAP, which then attaches near the lac operon promoter to help attract RNA polymerase, PROMOTING transcription.
Does cAMP inhibit or promote transcription?
PROMOTE
only _____ are removed by spliceosomes,
introns
prokaryotes do not have ____ or _____
introns, telomeres
______ is a type of post-transcriptional modification
Splicing
Conjugation
Transduction
Transformation
Conjugation: pilli
Transduction: different hosts TRANSFER
Transformation: transforming a new wardrobe, so you have to go buy new clothes (extracellular DNA)
Tryptophan _____ trypto production because it binds to the repressor protein (making it repress).
When tryptophan is NOT present, the repressor protein is inactive, soooo _____
decreases, tryptophan IS produced
Exonuclease
Cleaves nucleotides from the end of DNA, oftentimes for mismatch repair
One of the post-transcriptional modifications performed by only eukaryotes is ___ ______
RNA splicing
RNA splicing
where spliceosomes remove non-coding introns, leaving the final mRNA composed only of functional exons
Spliceosomes are proteins that catalyze the removal of introns from _____ transcripts. Because it acts upon mRNA and not _____, it does not contribute to _____ mutations.
mRNA, DNA, DNA
_____ during mRNA transcription in eukaryotes primarily serves to stabilize the mRNA molecule.
Polyadenylation
eukaryotic transcription occurs where? what does it use?
in the nucleus
uses RNA polymerase II to transcribe most genes.
Post-transcriptional modifications in Euk
Splicing out introns
5’ capping
Polyadenylation of the 3’ end
Enhancers bind to what?
Silencers bind to what?
Activators
Repressors
Transcription factors bind to what?
TATA box
Euk ribosome size
40S and 60S
Prok ribosome size
30S and 50S
Aminoacyl-tRNA synthetase
is the enzyme that attaches an amino acid to a specific tRNA using the energy from ATP
Aminoacyl-tRNA
refers to a tRNA bound to an amino acid.
Chaperonins
found in both eukaryotic and prokaryotic organisms and function in assisting newly synthesized polypeptides to fold into their correct shape.
Transposons
jumping genes!
DNA polymerase can contribute to DNA mutations, NOT ____ _____
RNA polymerase!!!!
Lysogenic:
Lytic:
Lysogenic: dormant, no harm
Lytic: active, HARM, lysing
