AA Catabolism and Metabolic Summary

Question 1

During AA catabolism, the amino group of an AA can be removed and either used to synthesize _____ compounds or it can be converted into _____ for excretion

Answer 1

synthesize nitrogenous compounds (i.e. nucleotide bases)

converted into urea for excretion

Question 2

During AA catabolism, once the amino group is removed, the remaining carbon skeleton, also called an __1__ acid, can either be broken down into __2__ and __2__, or it can be converted to __3__ or __3___.

Answer 2

1. alpha-keto acid
2. H2O and CO2
3. pyruvate (glucogenic AA) or acetyl-CoA (ketogenic AA)

Question 3

what enzymes are responsible for breaking proteins into individual AA?

Answer 3

proteases

Question 4

A glucogenic AA is broken down into __1___, while a ketogenic AA is broken down into __2___

Answer 4

1. pyruvate

2. acteyl-CoA

Question 5

What are the only 2 ketogenic AA?

Answer 5

lysine and leucine

Question 6

What’s the preferred fuel for cells?

Answer 6

carbohydrates

Question 7

Where does the liver receive its acetyl-CoA to use for fatty acid synthesis?

Answer 7

It uses the acetyl-CoA generated by pyruvate dehydrogenase complex

Question 8

Which of the following processes are stimulated by increased glucagon: glycolysis, gluconeogenesis, glycogenesis, glycogenolysis, protein anabolism, protein catabolism, FA synthesis, FA oxidation?

Answer 8

gluconeogenesis, glycogenolysis, protein catabolism, and FA oxidation

Question 9

When the body breaks down fatty acids for energy (occurs once glycogen stores are all used up), __1___ from adipose tissue are broken down into free FA and __2__ that are then released into the bloodstream.

Answer 9

1. triglycerides

2. glycerol

Question 10

The _____ can utilize the glycerol from triglyceride catabolism to generate glucose in gluconeogenesis.

Answer 10

liver

Question 11

Free FA in the bloodstream can be taken up by cells to run beta-oxidation, producing acetyl-CoA, which can be used in either ___1___ or used to generate ___2___

Answer 11

1. the Krebs cycle

2. ketone bodies via ketogenesis