Protein metabolism

What DOESN'T contribute to the amino acid pool?

• Degrading tissue proteins

• Making essential amino acids in the body

• Proteins from food

• Trick question! Everything contributes

How does stomach acid aid protein digestion?

• Disrupts ionic bonds so food proteins denature

• Hydrolyses peptide bonds to enzymes can "attack" food proteins

• Modulates amino acid transporters in the stomach wall

• Disrupts ionic bonds to activate enzymes

Which part of an amino acid provides a source of energy?

• The whole molecule

• The whole molecule EXCEPT the carboxyl group

• The whole molecule EXCEPT the amino group

• The amino group

In what form is N transported through blood to the liver?

• Ammonium ion

• Gluten

• An amino acid

• Urea

What makes an amino acid non-essential?

• Not metabolised by the body

• Not needed to build proteins but can be burnt for energy

• Must be provided by the diet

• Can be synthesised by the body

Pyridoxal phosphate can be temporarily converted to pyridoxamine phosphate. What type of reaction is this?

• Amination

• Deamination

• Oxidative deamination

• Transamination

What substrates does the enzyme cysteine transaminase need?

• L-cysteine + any amino acid

• L-cysteine + L-glutamate

• L-cysteine + any α-keto acid

• L-cysteine + α-ketoglutarate

Which type(s) of amino acids are NOT degraded in the liver?

• Aromatic chain

• Acidic chain

• Aliphatic chain

• Branched chain

Which amino acid has the most complex catabolism?

• Phenylalanine

• Tyrosine

• Tryptophan

• Asparagine

What is NOT a name for a form of vitamin B3?

• Niacin

• Nicotinate

• Nicotinic acid

• Nicotine