Exam 1 Random

Question 1

What nucleotide can be deaminated?

Answer 1

guanine -must be removed

Question 2

RNA polymerase is a?

Answer 2

DNA directed RNA polymerase

Question 3

RNA Guanine capping is in what direction?

Answer 3

5’-5’ linkage instead of 5’-3’

— stabilizes and protects from phosphates and nucleases

Question 4

TF2H is a multiprotein that?

Answer 4

includes XPB (bubble) and XPD (encounters base)
unwinds DNA at transcription start site
unwinds DNA at the site of damage
contain two proteins that if one is mutated, causes xeroderma pigmentation (XPA)

Question 5

etoposide

Answer 5

is a drug that targets the proteins (gyrase and topoisomerases) that detangle super-coils

Question 6

sickle cell anemia arises due to?

Answer 6

insolubility of hemoglobin due to a point mutation in primary structure affecting beta subunit

Question 7

chloramphenicol

Answer 7

inhibits protein synthesis by interfering with peptide bonds

Question 8

human genome composed of how many nucleotides?

Answer 8

3.2x10^9 (3.2billion)

Question 9

Shelterin complex

Answer 9

protect telomeres from DNA repair mechanisms, regulate telomerase activity. Consists of double- and single-stranded TTAGGG repeats and a single-stranded, G-rich overhang.

Question 10

Cordycepin

Answer 10

RNA transciption inhibitor

looks like 3’deoxyadenosine

Question 11

deoxyribose sugar plus a base is called?

Answer 11

nucleoside

Question 12

Pentose + base + PO4-

Answer 12

nucleotide

Question 13

template strand pairs with?

Answer 13

coding strand, mRNA strand, nascent DNA strand during DNA replication

Question 14

What AA is achiral?

Answer 14

glycine

Question 15

which AA are not used to assemble proteins in human cells?

Answer 15

D-amino

Question 16

alpha helix is stabolized by?

Answer 16

H-bonds between every 4th AA

Question 17

condition(s) resulting in reduced beta hemoglobin subunit

Answer 17

thalassemia major, beta-thallasemia, cooley anemia

Question 18

binding of a substrate to an enzymatic active site is primarily dependent on?

Answer 18

multiple weak interactions (like H-bonds)

Question 19

catalytic triad?

Answer 19

histidine, aspartate, serine

Question 20

Name AA that can be phosphorylated?

Answer 20

Tyrosine, serine, threonine

Question 21

difference between kinases and phosphatase?

Answer 21

• kinases= add phosphate to Tyrosine, serine, threonine

* phosphatases= remove phosphoryl group from Tyrosine, serine, threonine

Question 22

is myoglobin allosterically regulated?

Answer 22

NO. But hemoglobin is, 23BPG is an allosteric regulator (more 23BPG to heme, lower O2 affinity)

Question 23

when oxygen binds to hemoglobin, what happens?

Answer 23

O coordinates the iron atom in the heme prosthetic group, iron atom in heme moves into the plane of protoporphyin, histidine side chain is pulled closer to heme

Question 24

hydrolytic deaminations cause cytosine to be converted into?

Answer 24

uracil

Question 25

why does replication and transcription occur in 5’-3’ direction?

Answer 25

it would work 3’-5’ direction until proofreading removed a nucleotide… so it needs to be 5’-3’ so we have a mechanism of proofreading

Question 26

reverse transcriptase is a?

Answer 26

RNA directed DNA polymerase

Question 27

What gives DNA strand polarity?

Answer 27

the way base pairs are linked (pentose sugar linkages give a charge)

Question 28

6 common steps in DNA processing?

Answer 28

site recognition, helicase, SSB, Nuclease, polymerase. ligase

Question 29

proteins produced in human cells are comprised exclusively of?

Answer 29

L-amino acids

Question 30

What AA is very like collagen?

Answer 30

glycine

Question 31

What makes methionine and cysteine special?

Answer 31

They both have “S” in their side chains

Question 32

AA zwitterion example?

Answer 32

alanine (increase pH= decrease H= deprotinates; lower pH=increase H= protinated)

Question 33

What is a proenzyme?

Answer 33

an enzyme containing its reqired prothetic group or cofactor (Ex: holoenzyme)

Question 34

What bonds contribute to 3rd structure?

Answer 34

H-bonds, ionic, disulfide, hydrophobic

Question 35

What antibiotic acts by blocking the tRNA binding to the A-site in the ribosome?

Answer 35

tetracycline

Question 36

What AA are in histones? Also in SSB?

Answer 36

Lysine and Arginine (bc they have a + charge)

Question 37

Catalytic tetramer moves stuff into?

Answer 37

peroxisomes

Question 38

TOM complex and transolcons?

Answer 38

Move stuff into the ER or the ER membrane

Question 39

Zellweger Syndrome

Answer 39

mutation, “empty peroxisomes”

Question 40

isozyme

Answer 40

similar enzymes/AA sequence that catalyze the same reaction (but typically under different conditions and different regulators)
o *point: catalyze same reactant and have similar AA