AP BIO Unit 6- Juli's individual notes

TH Morgan

worked with fruit flies, found genes on chromosomes

Fredrick Griffith

working to find a cure to pneumonia, harmless live bacteria mixed with heat, transforming factor

Avery, McCarty and Macleod

injected protein in bacteria, no effect- injected DNA into bacterua, transformed harmless bacteria into virulent bacteria

Hershey and Chase

viruses that infect bacteria, used a blender, protein didn’t enter bacteria, DNA did enter bacteria

Chargaff

DNA composition, varies from species to species, all 4 bases not in equal quantity, bases present in characteristic ratio

Watson and Crick

developed double helix model of DNA

The DNA backbone

• refers to the 3’ and 5’ ends of the DNA

• the last trailing carbon

Anti parallel strands

complementary strand, runs in opposite direction

Bacteria chromosomes

they are circular, they have one origin of replication, replication proceeds in both directions until the fork meets

Can only add to the ________

3’ carbon

Energy comes from

ATP to ADP to AMP, AMP looks like a nucleotide

Ends of chromosomes

become eroded because that is where RNA primers was. Ends with a gap

BYOE

Bring your own energy

Ends of chromosomes are protected by_________

telomeres

Telomerase

adds copies of telomeres

Beadle and Tatum

used x-rays to inactivate genes, non functional enzyme=broken gene

One gene

one enzyme, one protein, one polypeptide, 1 product, was a theory by Beadle and Tatum that ended up being false

Central dogma

genetic info flows from DNA to RNA to protein

Initiation-in prokaryotes

RNA polymease binds to promoter sequence on DNA

Elongation- In prokaryotes

RNA polymerase unwinds DNA

Termination-in prokaryotes

RNA polymerase stops at __________ sequence, mRNA leaves region and translation can occur immediately

Prokaryotes

DNA in cytoplasm, circular chromosome, naked DNA, no introns

Eukaryotic

DNA in nucleus, linear chromosomes, DNA wound on histones, intorns vs exons

Transcriptions in Eukaryotes

3RNA polymerases enzymes

• RNA polymerase 2

transcribes genes into mRNA

• RNA polymerase 3

Only transcribes rRNA genes

• each has a specific promoter sequence it recognizes

Transcription factors bind to promoter region upstream of gene

TATA binding site

Pre mRNA

primary transcript

mature mRNA

mRNA processing, mRNA splicing=introns

5’ cap and poly A tail protects mRNA from___________

enzymes in the cytoplasm

snrps

small nuclear RNA, proteins

spliceosomes

several snRNP, act as enzymes, cut and paste

the Reading frame

splicing must be accurate, one mistake can change________

Transcription to translation- prokaryotes

simple and immediate translation

Transcription to translation- Eukaryotes

more complex, seperation in time and place, process RNA, transcription in nucleus, translation in cytoplasm

Order of amino acids

determine the structure of protein, coded by mRNA

Translation in prokaryotes

transcription and translation occur simultaneously in bacteria, DNA in cytosol, ribosomes read mRNA as it is being transcribed

codon

3 letter nucleotide code, triplet

anticodon

“clover leaf” end, amino acid attatched on 3’ end

Enzyme adds

substrate level

peptide bond

between amino acids

Point mutation

base pair substitution

silent mutation

new code still codes for the same amino acid

missense amino acid

change the amino acid it codes for

nonsense

codes for a STOP codon

Frameshift mutation

shifts reading frame

insertion

add a base

deletion

deleting a base

ribonucleases

breaksdown RNA

TATA box

binding site/promoter

Single stranded binding proteins

holds DNA apart

Ligase

glues together nucleotides

DNA polymerase 1

removes section of RNA primer and fixes anything wrong

RNA Primer/Primase

primes the spot so polymerase can attach and start adding

Topoisomerase

prevents DNA from getting too tightly wound

helicase

unwinds DNA

Operons

control gene expression in prokaryotes, it is the switch that turns on and off, located in the promoter region

repressible operon

usually on but sometimes is turned off, anabolic pathway, ex) tryp

Inducible operon

usually off but sometimes turned on, catabolic pathway, ex) lac

Negative gene regulation

operators are switched off by the active form of the repressor(o-lac, +tryp operon on own)

positive gene regulation

when the regulatory protein interacts directly with the genome to turn transcription on(-lac operon: only when glucose is in short supply and lactose is present(cAMP))

RNA polymerase is more likely to _______________

bind to its promoter when cAMP binds to CAP when there is a low amount of glucose. So when glucose is present as well as lactose the cell will not use the lac operon.

bacteria

no histones, circular DNA, gets some DNA from environment

Eukaryotic cells have ooprtunities____________________

to do gene expression compared to the lesser opportunities with prokaryotes

Chromatin modification

add acytle groups, enhance transcription, methyl group, stop transcription

enhancers

bending of DNA, enables activators to contact proteins @ the promoter, initiation transcription, more complex opporator

mRNA can

have different life span

Proteasomes

protein processing and degration are subject to regulation

noncoding RNA

can form complexes with proteins and influences gene expression

RNA i

RNA interference

induction

signaling molecules from embryo-tic cells cause transcriptional changes in target cells

PCR

Polymerase chain reaction, makes copies of protein RAPID

DNA cloning

use plasmids(Circular prokaryotic DNA molecules)

Restriction enzymes

cut DNA(enzyme), look for paledrome sequence(Also called endonucleases)

Recombiant DNA

different than original, mix DNA from 2 sources, meiosis

blunt ends

boarder to connect DNA with ligase

gel electrophoresis

used to separate macromolecules, use electric current, negatively charged, DNA moves toward the positive the smaller the fragment the faster it moves

CRISPR-Cas 9 system

Cas 9 bacterial protein that can cut DNA, precision scissor