questions from worksheets

Question 1

What are the main differences between fatty acid oxidation and synthesis?

Answer 1

oxidation is in mitochondria, synthesis in cytosol
FAD+ in oxidation, NADPH in synthesis
from carboxyl to methyl in oxidation, methyl to carboxyl in synthesis

Question 2

Steps of B-oxidation in fatty acids

Answer 2

fatty acid in cytoplasm
activation of fatty acid by joining with coA
reaction with carnitine
acyl coA in mitochondria
FAD linked oxidation
hydration
NAD+ linked oxidation
thiolysis

Question 3

How is citrate regulation of ACC make sense?

Answer 3

high citrate means that fatty acid synthesis is favorable, that means TCA cycle is providing plenty of ATP and NTs

Question 4

What are the stages of cholesterol biosynthesis?

Answer 4

1. synthesis of activated isoprenoid units
2. condensation of 6 isoprenoid units to form squalene
3. cyclization of squalene+ formation of cholesterol

Question 5

What is the committed step of cholesterol biosynthesis? Where is it located

Answer 5

HMGR to mevalonate is the committed step, located in the catalytic domain in the cytosol

Question 6

Why does protein denaturation in the stomach make better proteolysis?

Answer 6

Because the peptide bonds are more accessible

Question 7

What types of membrane proteins are in the lysosomal membrane?

Answer 7

proton pump, transport protein, glycosylated membrane proteins, fusion proteins

Question 8

What are the enzymatic steps for ubiquitin attachment?

Answer 8

E1: ubiquitin activating enzyme
E2: ubiquitin conjugating enzyme
E3: ubiquitin ligase

Question 9

Why does the 26s proteasome depend on ATP hydrolysis?

Answer 9

large protein must be unwrapped and pushed through the barrel

Question 10

How do aminotransferases and glutamate dehydrogenases cooperate in the metabolism of the amino group of amino acids?

Answer 10

amino transferases transfer the a-amino group to aka to form glutamate