gen bio 2 exam 3

Question 1

How many proteins can a cell have?

Answer 1

5000

Question 2

DNA ->?->RNA->?->protein

Answer 2

Transcription
Translation

Question 3

Nucleotide

Answer 3

Phosphate, Sugar, Nitrogenous base

Question 4

What are the nitrogenous bases?

Answer 4

Purines: Adenine, guanine
Pyrimidines: Cytosine, Thymine, Uracil

Question 5

Nulceoside

Answer 5

Pentose sugar + nitrogenous page

Question 6

Difference between ribose and deoxyribose

Answer 6

Ribose has an extra o at c’2

Question 7

Attatchments of Nucleotide

Answer 7

Phosphates attach to c5’, bases attach to c1’, and second nitrogenous bases in chain attached to c3’
Complimentary strands of 5’->3’

Question 8

Semiconservative Replication

Answer 8

When DNA is duplicated, the resulting daughter strands are 1/2 nascent, and 1/2 parent

Question 9

Lagging Strand

Answer 9

The bottom strand in duplication runs 5’->3’, but duplication needs to go 5’->3’ so RNA primease makes primers where RNA polymerase then runs 5’->3’

Question 10

Okazaki Fragment

Answer 10

Fragments of lagging strand, DNNA polymerase removes the primers and ligase connects the fragments

Question 11

DNA Polymerase

Answer 11

Reads the parent strand and synthesis the daughter DNA, at 50 bases/second, 1/100,000 bases are mutated.

Question 12

Ways to fix errors in DNA replication

Answer 12

• DNA polymerase can correct its own mistakes
• Mismatch repair is where a second DNA polymerase proofreads, and when it comes across and error it cuts out a section around the error, and ligase puts new section in
• Excision Repair: extra nucleotide inserted, and Polymerase cuts it out and a ligase repairs

Question 13

Telomeres

Answer 13

Repeated TTAGGG 200-2500 times to form a cap at the end of DNA, as due to DNA polymerase running 5’->3’ and a primer is needed, a few nucleotides are lost at the caps
Many cancer cells have active telomerase which repairs the telomere caps

Question 14

3 main types of RNA

Answer 14

mRNA - messenger RNA
tRNA - Transfer RNA
rRNA - Ribosomal RNA

Question 15

Transcription, 3 main steps and what is needed (transcription)

Answer 15

What is needed:
1) precursors (ATp,GTP,CTP,UTP)
2) energy (ATP)
3) enzymes (RNA polymerase)
4) Template (DNA)
3 main steps:
1)Initiation
2)Elongation
3)Termination

Question 16

Initiation (transcription)

Answer 16

Promoter (section of DNA where the polymerase attaches to)

Question 17

Elongation (transcription)

Answer 17

DNA is unwinded in the bubble, RNA polymerase adds RNA nucleotides to the template strand )5’->3’)

Question 18

Termination (transcription)

Answer 18

Termination sequence is section of DNA that makes the RNA polymerase detatch, then DNA winds back

Question 19

5’ cap

Answer 19

a 5’ cap is added to pre-mRNA, added to the 5’ end and is 7-mehtylguanine.

Helps stabilize mRNA
Assists w/ ribosome loading

Question 20

poly A tail

Answer 20

added to the 3’ end, hundreds of adenines

helps stabalize mRNA
helps w/ nuclear export

Question 21

Splicing

Answer 21

occurs to mRNA, introns are removed by snRNPs that form a spliceosome

Question 22

Translation

Answer 22

INITIATION
tRNA attatched to the small subunit, and then the large ribosomal subunit attatches.

ELONGATION
The anti-codon matches w/ codon, and when the amino acid is attatched the ribosome move forward 1 codon on the mRNA, and the tRNA moves to the exit site and a new tRNA enters the A site before movement. This repeats ntil termination sequence

TERMINATIOn

when termination codon is met (UUA, UGA, UAG) a termination factor attatches to the P site, and complex dissasembles

Question 23

Start and end codons

Answer 23

Start ; AUG
End: UUA, UAG, UGA

Question 24

Polyribosomes

Answer 24

Have a bunch of ribosomes translating one mRNA at once

Question 25

Signal Sequence

Answer 25

A sequence of amino acids that tells the Ribosome to bring the mRNA from the cytosol to finish translation in the Rough Endoplasmic Reticulum The Protein made is partially in rER, and is fully release din lumen of rER, sent to Golgi thru transport vesicle

Question 26

Golgi

Answer 26

Cis and trans face, adds sugars to proteins, and sends them away from the trans face

Question 27

Secretory vesicle

Answer 27

A transport vesicle but waits until a signal to merge w/ plasma membrane

Question 28

Chaperones

Answer 28

Proteins that help amino acids properly fold

Question 29

Proteolysis

Answer 29

When a newly formed AA chains is cut to form a properly folded protein

Question 30

Glycosylation

Answer 30

Golgi does this, adding sugar chains to proteins for targeting/recognition

Question 31

Phosphorylation

Answer 31

"on" and "off" for proteins, adding of negative phosphate group.

Question 32

Kinase

Answer 32

Adds the phosphates in phosphorylation

Question 33

Phosphatase

Answer 33

Remove phosphates from proteins

Question 34

Inducible vs Repressible genes

Answer 34

Inducibles start off and are induced by high "substrates", and repressed by low levels of substrate, heat chock proteins repressibles start on, and are repressed by high levels of product, glycolysis when high ATP glycolysis stops

Question 35

mRNA degredation

Answer 35

mRNA not stable in the cytosol mRNA turnover, how much mRNA is made vs how fast it is broken down

Question 36

Proteosome

Answer 36

Protein machinery that breaks down proteins to their amino acid constituents, only breaks down things marked with ubiquitin

Question 37

The cause of some neurodegenerative disorders

Answer 37

The proteosome doesn't function properly leading to accumulation of proteins

Question 38

Epistasis

Answer 38

Expression of one gene affects another

Question 39

Expressivity

Answer 39

The degree to which a genotype is expressed in an individual

Question 40

Polydactylism

Answer 40

Having extra digits

Question 42

Helicase

Answer 42

Unwinds and opens DNA

Question 43

RNA primase

Answer 43

forms the RNA primer on the DNA template for polymerases to attach to

Question 44

DNA polymerase

Answer 44

attaches to 3' of previous nucleotide, and builds DNA strand