Overview of Protein Biochemistry

Question 1

What are essential amino acids?

Answer 1

Those that the body can’t make

Question 2

Conditionally essential amino acids are those that _____________.

Answer 2

the body can make, but the substrates needed to make them may be quite finite

Question 3

The amino acid ______ is used to shuttle nitrogen out of the body.

Answer 3

glutamine

Question 4

Amino acids can be _______-genic or _________-genic.

Answer 4

keto; gluco

Question 5

There are two ways that proteins can be degraded within cells: ________________.

Answer 5

lysosome degradation and ubiquitination

Question 6

ALT converts ________________.

Answer 6

alanine to pyruvate (for gluconeogenesis)

Question 7

AST converts ________________.

Answer 7

aspartate to oxaloacetate

Question 8

Trace the pathway by which nitrogen leaves the body.

Answer 8

It follows a transamination reaction to glutamate (from an amino acid) and then glutamate dehydrogenase pulls NH3 off.

Question 9

___________ is a post-translationally modified amino acid that is part of the urea cycle.

Answer 9

Ornithine

Question 10

The first key step in protein degradation is ______________.

Answer 10

absorption of NH4 from proteins by carbamoyl phosphate; the product of this reaction enters the urea cycle and absorbs another amine group from aspartate to become urea

Question 11

___________ becomes aspartate when you take the amino group off.

Answer 11

Oxaloacetate

Question 12

___________ becomes glutamate when you add an amino group to it.

Answer 12

Alpha-ketoglutarate

Question 13

Glutamine synthase absorbs __________ from tissues and puts it onto ____________.

Answer 13

NH3; glutamate