Protein

Question 1

Transamination

Answer 1

• The amine of an amino acid can’t be used for energy and is transferred away from AA
  A-amino group is removed by transferring it to a-ketoglutrate to make glutamate and a-keto
  Catalysed by amino transferase

E.g Alanine + a-keto = pyruvate + gluatamate

Question 2

Deamination

Answer 2

After Transamination, glutamate is transported to the liver mitochondria
Enters mitochondria matrix, where amino group is removed by glutamate dehydrogenase
Removal of amino group causes Amonia (NH3) and a-keto group to form
Amino group is processed for excretion and the ammonia is converted to urea and excreted

Question 3

Micronutrient which acts as co-enzyme

Answer 3

Pyridoxal phosphate active form of vitamin B6
Facilitates the transfer of amino groups between amino and keto acids

Question 4

Dietary amino acids

Answer 4

Proteins are digested in gastrointestinal tract by pepsin into peptides and FFA absorbed into the blood stream and transported to various tissues

Question 5

Transport of FFA

Answer 5

FFA are insoluble in blood must be bound to albumin to be transported in the blood
Diffuse across the cell membrane - down their concentration gradient
Once inside the cell, FA’s are activated to fatty acyl-coa
Requires 2ATP
FA transported into the mitochondria

Question 6

Degraded intercellular proteins

Answer 6

Proteins within cells undergo continuous turnover, old/damaged proteins are degraded
Peptide bonds are cleaved, releasing AA’s into the cytoplasm
Proteins released contribute to FAA pool, where they are available for protein synthesis

Question 7

Glycogenic

Answer 7

-Can be converted into glucose via glucogensis
-form glucose precusois
-Include essential & non essential AA

Question 8

Ketogenic

Answer 8

-form acetyl COA
-form precursor for ketone bodies
-include only lysine & leucine

Question 9

Location of the urea cycle

Answer 9

Primarily occurs in liver

Question 10

Function of the urea cycle

Answer 10

To remove excess ammonia from the body.
Ammonia is generated from the breakdown of AA during protein metabolism
Can be toxic to cells in if accumulated in high concentrations