MODULE 4

Question 1

when was DNA discovered

Answer 1

late 1800s

Question 2

when was DNA identified as the inheritance model

Answer 2

1950s

Question 3

what is DNA made of

Answer 3

dNTPs (deoxyribonucleotide 5’ triphosphates)
- ATCG

Question 4

what denatures DNA

Answer 4

Heat, OH-

Question 5

what renatures DNA

Answer 5

renatures overtime with specialized environmental conditions

Question 6

what us the function of DNA

Answer 6

hold genetic information
- no structural function

Question 7

How are prokaryotes (bacteria and archaea) organized into chromosomes

Answer 7

• 1 copy (haploid) + 1 chromo
• circular chromos (exceptions
• supercoiled by topoisomerase

Question 8

how are eukaryotes organized into chromosomes

Answer 8

• 2 copies (diploid)
• more than 1 chromo
• linear chromos
• packed with histones

Question 9

what are plasmids and what do they do

Answer 9

• Plasmids are small, circular pieces of DNA that exist separately from the main chromosome
• they add function to the bacteria like Antibiotic resistance

Question 10

what is an example of extrachromosomal DNA

Answer 10

a plasmid

Question 11

what is the central dogma of biology

Answer 11

DNA –> RNA –> protein

Question 12

what are the information macromolecules

Answer 12

Nucleic acids
Proteins

Question 13

what’s the difference between a genotype and a phenotype

Answer 13

Phenotype: The observable traits you actually see
Genotype: The genetic makeup of an organism

Question 14

TF phenotype = environmental conditions + genotype

Answer 14

T

Question 15

what are the enzymes needed for DNA replication in chronological order

Answer 15

-Topoisomerase
-Helicase
-Single-stranded binding proteins (SSBs)
-Primase
-Sliding clamp
-DNA polymerase III
-DNA polymerase I
-Ligase

Question 16

what is an okazaki fragment

Answer 16

short piece of newly made DNA that’s synthesized on the lagging strand

Question 17

what does topoisomerase/gyrase do

Answer 17

Relieves supercoiling and tension(stress) ahead of the replication fork

Question 18

what does helicase do

Answer 18

Unwinds the double helix by breaking hydrogen bonds

Question 19

what do single stranded binding proteins do

Answer 19

Bind to the separated strands to keep them from re-annealing

Question 20

what do primases do

Answer 20

synthesizes short RNA primers so DNA synthesis can start

Question 21

what do sliding clamps do

Answer 21

Attaches to DNA and holds DNA polymerase in place

Question 22

what does DNA polymerase 3 do

Answer 22

Main enzyme that synthesizes new DNA (5′ → 3′) on leading and lagging strands

Question 23

what does DNA polymerase 1 do

Answer 23

Removes RNA primers and replaces them with DNA

Question 24

what does ligase do

Answer 24

Seals the remaining nicks between Okazaki fragments

Question 25

what are the different types of RNA

Answer 25

mRNA tRNA rRNA

Question 26

whats the function of mRNA

Answer 26

intermediary between DNA and protein, used by ribosome, encodes a protein

Question 27

whats the function of rRNA

Answer 27

ensure proper tRNA, mRNA, and ribosome alignment, catalyzes peptide bond between AAs

Question 28

whats the function of tRNA

Answer 28

carries correct AA to site of protein synthesis

Question 29

what is a Rho protein

Answer 29

Rho (ρ) protein is a transcription termination factor in bacteria. Its job is to stop transcription at specific sites on mRNA.

Question 30

what are the 3 components essential for DNA replication

Answer 30

primase helicase DNA ligase

Question 31

TF RNA polymerase needs a primer

Answer 31

F

Question 32

Why do bacteria have more than 1 sigma factor

Answer 32

Provides genetic regulation of transcription and help bacteria respond to the environment

Question 33

what is a sigma factor and where is it located

Answer 33

Sigma factors bind to DNA sequences in the promoter region (especially the –35 and –10 boxes in bacteria). - help RNA polymerase know where to begin

Question 34

what is the transcriptional RNA unit

Answer 34

RBS (ribosomal binding site) + open reading frame(s)

Question 35

what do the operon and promoter do

Answer 35

recruits sigma factors

Question 36

what is monosystronic vs polysystronic mRNA

Answer 36

- monocistronic mRNA molecule carries the genetic info to code for only one protein (eukaryote) - A polycistronic mRNA molecule carries the genetic information to code for multiple, often functionally related, proteins. (prokaryote)

Question 37

what is a stem loop

Answer 37

GC rich termination sequence

Question 38

hoes does Rho dependant termination work

Answer 38

Rho is an ATP-powered motor that rides the RNA highway to track down and dismantle the transcription machinery at specific destinations.

Question 39

what does tRNA hold in terms of genetics

Answer 39

the anticodon

Question 40

what does the A site on a ribosome

Answer 40

accept the anticodon tRNA

Question 41

what does the p site do on a ribosome

Answer 41

bind the amino acids in a polypeptide chain

Question 42

what does the E site do in ribosomes

Answer 42

releases the tRNA

Question 43

how does translation work in prokaryotes vs eukaryotes

Answer 43

Prokaryotes start translation at Shine-Dalgarno sequences on polycistronic mRNA, while eukaryotes scan from the 5' cap of monocistronic mRNA.

Question 44

what is codon bias

Answer 44

Bacteria uses certain tRNAs

Question 45

TF we can block the A P and E sites with antibiotics

Answer 45

T

Question 46

what is needed in order to get a functional protein

Answer 46

protein folding chaperones

Question 47

what do chaperones do

Answer 47

Add cofactors and help folding