Amino Acid Synthesis and Degradation

Question 1

Where do we get nitrogen from?

Answer 1

Proteins

Question 2

What is meant by nitrogen balance?

Answer 2

Nitrogen in - Nitrogen out

We do not have excess nitrogen

Question 3

What is normal nitrogen balance?

Answer 3

Zero

Question 4

How does our body get rid of nitrogen?

Answer 4

Urea in urine

Question 5

What transports di- and tripeptides from the intestines?

Answer 5

PEPT1 transporter (cotransporter with H)
NHE (Na in H out for PEPT1)

Question 6

What occurs to AA in the fasting state?

Answer 6

They are moved from muscle to the liver and kidney via glutamine alanine cycle

Question 7

What pair of AA are often used in transamination reactions?

Answer 7

Glutamate and alpha ketoglutarate (glutamate deaminated to alpha keto)

Question 8

PLP is needed in what reaction?

Answer 8

Transamination

Question 9

What does PLP come from?

Answer 9

Vitamin B6

Question 10

Mnemonic for non-essential AA?

Answer 10

These (tryptophan)
Ten (threonine)
Valuable
Amino-acids
Have 
Long
Preserved (phenylalanine)
Life 
In
Man

Question 11

What is the only AA that does not participate in transamination reactions?

Answer 11

Lysine

Question 12

Which amino acids are derived from glycolysis intermediates?

Answer 12

Cysteine
Glycine
Serine
Threonine
Tryptophan

Question 13

Which amino acids come from alpha-ketoglutarate?

Answer 13

Histidine
Arginine
Proline
Glutamate
Glutamine

Question 14

How can ammonium be added to make molecules other than transamination?

Answer 14

Synthetase uses ATP to add NH3+

Question 15

What does GDH (glutamate dehydrogenase) do?

Answer 15

Takes NH3+ from glutamate converting it to alpha-ketoglutarate

Question 16

What AA are derived from fumarate?

Answer 16

Aspartate
Tyrosine
Phenylalanine

Question 17

Which AA are propiogenic?

Answer 17

Valine
Isoleucine
Methionine
Threonine

Question 18

What does propiogenic mean?

Answer 18

Can be catabolized to produce energy

Question 19

What do propiogenic AA enter TCA as?

Answer 19

Succinyl CoA

Question 20

What AA enter TCA as oxaloacetate?

Answer 20

Aspartate

Asparagine

Question 21

What AA is made from pyruvate to enter the blood as a shuttle?

Answer 21

Alanine

Question 22

What is propionic acidemia?

Answer 22

Defective propionyl CoA carboxylase

Question 23

What is propionyl CoA carboxylase needed for?

Answer 23

Conversion of propionyl CoA to methylmalonyl CoA to enter TCA (the way propiogenic AA enter)

Question 24

What can cause Kwashiorkor?

Answer 24

Not enough liver production of albumin due to lack of dietary protein causing decreased osmotic pressure

Question 25

What is marasmus?

Answer 25

Muscle wasting; muscle are broken down for proteins needed