other people final review

Question 1

what is the shine-Dalgarno sequence?

Answer 1

sequence upstream of AUG in prokaryotes

Question 2

What is the Kozak context?

Answer 2

sequence embedded AROUND AUG

Question 3

what does a peptidyl transferase catalyze?

Answer 3

forms the bond between two amino acids in the peptidyl site and aminoacyl site while they are still bound to tRNA, and a stop codon is not recognized and a water molecule is bound

Question 4

Actinomycin-D and acridine

Answer 4

Inhibits RNA elongation by intercalating into the DNA template (transcription inhibitor)

Question 5

Streptomycin function

Answer 5

Binds to the 30s subunit and alters its structure to inhibit the initiation of protein synthesis in prokaryotes

Question 6

Tetracyclines

Answer 6

Interacts with small ribosomal subunits and blocks the access of aminoacyl-tRNA to the mRNA-ribosome complex in prokaryotes

Question 7

Puromycin function

Answer 7

Resembles aminoacyl-tRNA and is incorporated into the growing chain and inhibits further elongation in BOTH prokaryotes and eukaryotes

Question 8

Chloramphenicol function

Answer 8

inhibits prokaryotic peptidyltransferase, and can also inhibit mitochondrial protein synthesis

Question 9

Clindamycin and Erythromycin function

Answer 9

Binds irreversibly to the 50s subunit in bacteria

Question 10

Diphtheria toxic

Answer 10

Inactivates the eukaryotic elongation factor (eEF-2) which prevents translocation of ribosome

Question 11

Rifampicin

Answer 11

Inhibits initiation of bacterial RNA synthesis by binding to the b subunit of the polymerase for TB treatment
(Inhibits Transcription)

Question 12

a-amanitin

Answer 12

Mushroom toxin
Blocks eukaryotic Pol II and III. Blocks all transcription

Question 13

what are the effects of glucose and lactose on the lac operon?

Answer 13

low glucose= cap bound
lactose unavailable= repressor bound
low glucose + low lactose= lac not expressed
low glucose + lactose= lac strongly expressed
glucose + low lactose= lac not expressed
glucose + lactose= very low expression
“use lactose if glucose not available”

Question 14

do regulatory proteins need to be on the same piece of DNA that they regulate?

Answer 14

Yes, DNA bending can bring an activator protein, bound to an enhancer element into contact with transcription complex

Question 15

How to glucocorticoids regulate gene transcription?

Answer 15

1. steroid diffuses into cells and binds to receptor protein
2. receptor-steroid complex goes into nucleus
3. the complex binds to a regulatory sequence
   also called hormone response element
   similarities between enhancer elements

Question 16

SNOW DROP

Answer 16

how to test pneumonic
Southern- DNA
Northern- RNA
skip O
Western- Protein

Question 17

DNA forms?

Answer 17

b-form= primary form
a-form= DNA with RNA hybrid
z-form= reverse helix form, usually near promotors

Question 18

pol alpha, primase, and DNA ligase function

Answer 18

pol alpha synthesizes DNA
primase synthesizes a RNA primer
ligase seals nick at end of lagging strand and used in DNA repair

Question 19

sickle cell anemia mutation

Answer 19

amino acid change from Glu to Val makes a “sticky” point which associates with other heme groups

Question 20

hemoglobin R versus T state

Answer 20

R state “left shift” high affinity state (reduces oxygen delivery to tissues) when theres more oxygen available
T state “right shift” is low affinity (increased oxygen delivery to tissues)

Question 21

what are the essential amino acids

Answer 21

PVT TIM HaLL
phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, lysine

Question 22

how is aspartate synthesized using coupled transamination

Answer 22

1. alanine broken into pyruvate by alanine aminotransferase and gives off glutamate
2. glutamate converted into alpha-ketoglutarate by aspartate aminotransferase which gives off a aspartate

Question 23

synthesis of tyrosine? cofactor and deficiency

Answer 23

phenylalanine converted using phenylalanine hydroxylase which requires tetrahydrobiopterin
Deffect causes buildup of phenylalanine which causes phenylketonuria

Question 24

what substances are glucogenic?

Answer 24

amino acids, lactate, glycerol, and propionate

Question 25

where is glucose-6-phosphatase and whats is its function?

Answer 25

found on the luminal surface of ER (mainly in the liver) to remove the phosphate group to transport glucose out of the liver

Question 26

what is the major source of energy when fasting for >24 hours?

Answer 26

muscle protein and some glucose from glycerol from fat, but amino acids supply most of the carbon needed

Question 27

glucose-6-phosphate dehydrogenase deficiency

Answer 27

results in hemolytic anemia
X-linked
Can occur do to oxidative stress
NADPH production is impaired. Only erythrocytes affected because they rely on PPP as sole source of NADPH, so detox is inhibited

Question 28

Transketolase

Answer 28

requires thiamine (B1) from thiamine pyrophosphate
some mutations cause transketolase to bind TPP more weakly which makes them more susceptible to wernicke-korsakoff and beri-beri

Question 29

Complex 1 in ETC

Answer 29

NADH dehydrogenase
NADH provides electron pair which is transported by flavin nucleotide
mutations lead to Lebers hereditary optic neuropathy and leigh syndrome

Question 30

Complex 2 in ETC

Answer 30

Succinate dehydrogenase (part of citric acid cycle)
glycerol phosphate dehydrogenase shuttle

Question 31

DRAACCO

Answer 31

2,4-dinitrophenol- weight loss (can cross back n forth)
Rotenone: complex one
antimycin “an-3-mycin”: complex 3
Cyanide, carbon monoxide, azide: inhibit complex 4

Question 32

how does arsenite work?

Answer 32

it covalently bind to the sulfydryl arms in the lipolysyl arms of E2 in the pyruvate dehydrogenase complex and acetyl-CoA production stops

Question 33

what does zileuton do?

Answer 33

respiratory inhaler that inhibits 5-lipoxygenase and prevents 5-HPETE from being produced

Question 34

What do NSAIDS do?

Answer 34

block COX and prohibit the production of PGG2

Question 35

what do steroids do? like progesterone

Answer 35

prohibits the production of arachidonic acid from cell membrane phospholipids. prohibits all eicosanoid metabolism

Question 36

what is PGE2?

Answer 36

also called dinoprostone
induces fever, vasodilation, ripens cervix

Question 37

what is PGF2

Answer 37

also called dinoprost and carboprost
vasoconstriction, contracts smooth muscle, stimulates uterine contractions

Question 38

what is PGI2?

Answer 38

prostacyclin, I class of prostaglandins
produced by endothelium of blood vessels
vasodilation, inhibit platelet aggregation, increases cAMP

Question 39

Thromboxans?

Answer 39

“causes thrombosis”
stimulates aggregation, vasoconstriction, mobilize calcium