Proteins + Lipids

Question 1

How many different apoproteins are made from one gene

Answer 1

RNA editing

Question 2

Trysinogen is activated by

Answer 2

enteropeptidase

Question 3

Activates most proteolytic enzymes

Answer 3

trypsin

Question 4

Endopeptidases

vs

Exopeptidases

Answer 4

endo: cut within chain
exo: cut off end of chain

Question 5

Cystic fibrosis and protein metabolism

Answer 5

pancreatic duct becomes blocked

secretion of pancreatic proteases inhibited

malabsoption of proteins and other nutrients

Question 6

AA transport lumenal surface of intestinal epithelium

Answer 6

sodium-linked

facilitated transport when favorable

Question 7

B₀ transporter

Answer 7

zwitterionic aa transporter

Trp primary aa

SLC6A9 mutation

Hartnup disease

pallegra-like: diarrhea, dementia, dermatitis

Question 8

B₀₊ transporter

Answer 8

basic aa transporter

ie Arg, Lys, His

SLC7A9 or SLC3A1 mutations

cysteinuria → kidney stones

Question 9

SLC6A9 mutation

Answer 9

B₀ transporter

Trp

deficiency: Hartnup disease

pallegra-like:

diarrhea, dermatitis, dementia

Question 10

SLC7A9 mutation

Answer 10

B₀₊ transporter

basic AA: Arg, Lys, His

⇒ cysteinuria, cysteine stones

Question 11

SLC3A1 mutation

Answer 11

B₀₊ transporter

basic AA: Arg, Lys, His

⇒ cysteinuria, cysteine stones

Question 12

Structure of glutathione

Answer 12

glycine - cysteine - glutamate

Question 13

Mechanism of glutathione

Answer 13

gamma-glutamyl transpeptidase

cleaves Gly - Cys - Glu

between Cys - Glu bond

Glu binds extraceullar aa and brings it inside

Gly - Cys recycled

Question 14

GGT test

Answer 14

gamma-glutamyl transferase

normally moves aa into gut epithlial cells

used to see if alcoholics have been drinking recently

Question 15

Dietary protein functions

Answer 15

neurotransmitters

⇒ makes sense, neuro deficits with deficiency of proteins

other N-containing compounds

intercellular proteins

Question 16

Control of protein synthesis

Answer 16

sensitive to cellular metabolism and hormonal influences

Question 17

Major intracellular regulator of protein metabolism

Answer 17

AMPK

(AMP-kinase)

activates PKA

(protein kinase A)

resulting in P of many targets and overall shift in cellular metabolism

Question 18

ACC

acetyl-CoA carboxylase

Answer 18

phophorylated by AMPK

blocks lipid synthesis

Question 19

TSC1/2

Answer 19

phosphorylated by AMPK

inhibits mTOR

activates autophagy

proteolysis of intracellular proteins

Question 20

Apoproteins

which go where

Answer 20

ApoB48: added to make nascent chylomicrons

ApoB100: added to make nascent VLDL

ApoCII: added to nascent chylomicrons and VLDL by HDL to to make substrates for LPL (lipoprotein lipase)

ApoE: added to chylomicrons and VLDL by HDL along with ApoCII

Question 21

Distributors of dietary:

fat

carbs

Answer 21

fat: chylomicrons
carbs: VLDL