MEH protein/aa metabolism

Question 1

what are the essential aa?

Answer 1

histidine, 
isoleucine,
leucine, 
lysine, 
methionine, 
phenylalanine, 
threonine, 
tryptophan,
valine.

(arginine semi essential)

(if learned this huge list may prove truly valuable OR I love Lucy very much, please try to help Arg)

Question 2

Which amino acid is utilised for the transport of ammonia from peripheral tissues to the liver?

Answer 2

Alanine.

Question 3

describe phenylketonuria?

Answer 3

a deficiency in phenylalanine hydroxylase

> meaning phenylalanine can’t be converted to tyrosine.
causes phenylalanine (a ketogenic amino acid) to build up, and through transamination, so do phenylketones.
These are then filtered in the kidney and appear in the urine.

Question 4

Which amino acid is also used for glutathione production?

Answer 4

cysteine

Question 5

Define transamination

Answer 5

reversible process.

swapping an amino group on an amino acid to a carboxyl group to produce an intermediate for respiration (so can be used to capture energy),

or swapping the carboxyl group for an amino group to create an amino acid.

Question 6

presentations of phenylketonuria?

most common?

Answer 6

Developmental delay.
Small head.
Heel prick test.
Hypopigmentation.

Question 7

describe briefly amino acid catabolism

Answer 7

1) removal of the amino group > converted to urea and excreted
2) C- skeleton of aa is converted to aa precursor (e.g. acetyl co A, oxaloacetate, pyruvate, succinate etc)

Question 8

differences between ketogenic and glycogenic aa?

Answer 8

keto- aa that produces acetyl coA (used in ketone synthesis)

gluco- aa that produces other organic pre-cursor molecules and can be used in glucneogenesis

Question 9

products of aa degradation?

Answer 9

urea, 
pyruvate, 
acetyl~CoA, 
α-ketoglutarate, 
oxaloacetate, 
succinate 
fumarate.

Question 10

which processes produce ammonia?

Answer 10

• deamination of amino acids

- absorbed from gut where it is produced by bacterial action.

Question 11

what does the Glutaminase enzyme do?

Answer 11

Glutaminase is a high specificity enzyme that converts glutamine to glutamate + NH3.