Biochem

Question 1

type I collagen

Answer 1

most common (90%)
Bone
Skin
Tendon
dentin
fascia
cornea
late wound repair

defective in osteogenesis imperfecta

type I = bONE

Question 2

type II collagen

Answer 2

Cartilage (including hyaline)
vitreous body
nuclear pulposus

type II = carTWOlage

Question 3

type III collagen

Answer 3

Reticulin - skin, blood vessels, uterus, fetal tissue, granulation tissue

type III = defective in Ehlers-Danlos (threE D)

Question 4

type IV collagen

Answer 4

basement membrane
basal lamina

type IV = under the FLOOR (BM)

defective in Alport synd

Question 5

ApoA-I

Answer 5

LCAT activation (cholesterol esterification)
only in HDL

Question 6

ApoB-48

Answer 6

chylomicron assembly and secretion by intestine to lymphatics
found in chylomicrons + remnants of chylomicrons

Question 7

ApoB-100

Answer 7

LDL particle uptake by extrahepatic cells (BINDS LDL receptor)
found on VLDL, IDL, LDL

Question 8

ApoC-II

Answer 8

LPL activation (cofactor for)
found on chylomicrons, VLDL, HDL

Question 9

ApoE3 & E4

Answer 9

VLDL and chylomicron remnant uptake by liver cells

found on all, EXCEPT LDL!

Question 10

vimentin

Answer 10

CT;

sarcomas

Question 11

desmin

Answer 11

muscle;

rhabdomyosarcoma, leiomyosarcoma

Question 12

cytokeratin

Answer 12

epithelial cells;

carcinomas

Question 13

GFAP

Answer 13

neuroglia (astrocytes, schwann cells, etc.);

astrocytomas, glioblastomas

Question 14

neurofilaments

Answer 14

axons w/in neurons;

neuroblastomas, primitive neuroectodermal tumors

Question 15

peripherin

Answer 15

neurons

Question 16

nuclear lamins (A,B,C)

Answer 16

nuclear envelope structural framework and DNA within

Question 17

elastin contains which AA?

Answer 17

proline + glycine

Question 18

enzymes that use B1 (thiamine) as cofactor

Answer 18

pyruvate dehydrogenase
alpha-ketoglutarate dehydrogenase
transketolase

Question 19

rate limiting step in purine synth

Answer 19

glutamine PRPP amidotransferase

Question 20

rate-limiting step in pyrimidine synth

Answer 20

CPS-II

Question 21

needed to make pyrimidines

Answer 21

carbomyl phosphate (from ATP, CO2, glutamine)
aspartate

Question 22

needed to make purines

Answer 22

glycine
aspartate
glutamine
THF
CO2

Question 23

causes the positive charge of histones

Answer 23

lysine

arginine

Question 24

causes the negative charge of DNA

Answer 24

phosphate groups

Question 25

OTC deficiency vs orotic aciduria (Lab finding)?

Answer 25

OTC def - elevated serum ammonia

orotic aciduria - normal serum ammonia

Question 26

eukaryotic DNA polymerase making own primer

Answer 26

alpha

Question 27

eukaryotic DNA polymerase that replicates lagging strand

Answer 27

alpha

Question 28

eukaryotic DNA polymerase that builds leading strand

Answer 28

delta

Question 29

eukaryotic DNA polymerase that repairs DNA

Answer 29

beta

Question 30

eukaryotic DNA polymerase that replicates mitochondrial DNA

Answer 30

gamma

Question 31

prokaryotic DNA polymerase w/ 3’–>5’ exonuclease activity

Answer 31

DNA polymerase III

Question 32

function of 3’–>5’ exonuclease

Answer 32

proofread - removes/replaces mismatched nucleotides

Question 33

prokaryotic DNA polymerase w/ 5’–>3’ exonuclease activity?

Answer 33

DNA polymerase I

Question 34

function of 5’–>3’ exonuclease

Answer 34

degrades RNA primer and replaces it w/ DNA

Question 35

most abundant RNA

Answer 35

rRNA

Question 36

longest RNA

Answer 36

mRNA

Question 37

smallest RNA

Answer 37

tRNA

Question 38

what makes rRNA in eukaryotes

Answer 38

RNA polymerase I

Question 39

what makes mRNA in eukaryotes

Answer 39

RNA polymerase II

Question 40

what makes tRNA in eukaryotes

Answer 40

RNA polymerase III

Question 41

what provides the cap for mRNA

Answer 41

S-adenosyl-methionine (SAM)

7-methylguanosine cap

Question 42

what is the polyadenylatin signal

Answer 42

AAUAAA

Question 43

irreversible enzymes involved in gluconeogenesis

Answer 43

pyruvate carboxylase
PEP carboxykinase
fructose-1,6-bisphosphatase (rate-limiting)
glucose-6-phosphatase

Question 44

rate-limiting enzyme of glycolysis

Answer 44

PFK-1

Question 45

pyruvate dehydrogenase complex requires which 5 cofactors?

Answer 45

pyrophosphate (B1, thiamine; TPP)
Lipoic acid - inhib by arsenic (see: garlic breath)
CoA (B5, pantothenate)
FAD (B2, riboflavin)
NAD (B3, niacin)

“Tender Loving Care (TLC) For Nobody”

Question 46

2 purely ketogenic AA

Answer 46

lysine

leucine

Question 47

possible products of pyruvate

Answer 47

alanine
acetyl CoA
lactate
oxaloacetate

Question 48

2 main nitrogen transporters in blood

Answer 48

alanine

glutamine

Question 49

tissues that use pentose phosphate pathway

Answer 49

lactating mammary glands
liver
adrenal cortex
RBCs

Question 50

BH4 (tetrahydrobiopterin) cofactor in synth of what?

Answer 50

serotonin
tyrosine
dopa
NO

Question 51

4 functions of NADPH

Answer 51

1) synth FA and cholesterol
2) generate ROS
3) protect RBC from ROS damage
4) CYP450 enzymes

Question 52

3 substrates that can undergo substrate level phoshorylation to create high-energy products (ATP or GTP)

Answer 52

• 1,3-BPG
• PEP
• succinyl-CoA (makes GTP)

Question 53

only step in glycolysis that makes NADH

Answer 53

glyceraldehyde-3-P –> 1,3-BPG

Question 54

highest energy compound of glycolysis

Answer 54

PEP

Question 55

in RBC, NADH needed to do what?

Answer 55

turn Met-Hb to Hb

Question 56

breakdown of malate yields?

Answer 56

increased NADPH –> increased FA synthesis