CPN CPN Nutrient Metabolism & Physiology 1 — Questions and Answers
Question 1: Which amino acid is considered essential for cats because they cannot synthesize adequate amounts from cysteine and methionine?
- Lysine
- Taurine (Correct answer)
- Methionine
- Arginine
Correct answer: Taurine
Taurine is an essential amino acid for cats because they lack sufficient enzymatic activity to synthesize it endogenously, making dietary taurine required for cardiac and retinal health.
Question 2: A protein with a biological value (BV) of 100 indicates what about its nutritional quality?
- 50% of the protein is digestible
- All absorbed protein is retained and utilized by the body (Correct answer)
- It contains all essential amino acids in equal amounts
- It has zero digestive losses
Correct answer: All absorbed protein is retained and utilized by the body
A biological value of 100 means that 100% of the absorbed protein is retained for body use, representing the theoretical maximum efficiency of protein utilization.
Question 3: Which metabolic process converts excess amino acids into glucose during periods of carbohydrate deficiency?
- Glycolysis
- Gluconeogenesis (Correct answer)
- Glycogenolysis
- Beta-oxidation
Correct answer: Gluconeogenesis
Gluconeogenesis is the hepatic process that synthesizes new glucose from non-carbohydrate precursors such as amino acids, lactate, and glycerol.
Question 4: Dogs can synthesize limited amounts of niacin from which essential amino acid, though dietary niacin is still required?
- Phenylalanine
- Histidine
- Tryptophan (Correct answer)
- Tyrosine
Correct answer: Tryptophan
Dogs possess some capacity to convert tryptophan to niacin, but the conversion efficiency is too low to meet full requirements without dietary supplementation.
Question 5: Which nitrogen balance state indicates adequate protein intake for a healthy adult pet at maintenance?
- Positive nitrogen balance
- Zero (equilibrium) nitrogen balance (Correct answer)
- Negative nitrogen balance
- Fluctuating nitrogen balance
Correct answer: Zero (equilibrium) nitrogen balance
Zero nitrogen balance, where nitrogen intake equals nitrogen excretion, indicates the animal is neither gaining nor losing body protein, which is appropriate for healthy adult maintenance.
Question 6: Which organ is the primary site of amino acid catabolism and urea synthesis in companion animals?
- Kidney
- Small intestine
- Liver (Correct answer)
- Pancreas
Correct answer: Liver
The liver is the central site of amino acid catabolism and converts toxic ammonia (from deamination) to urea via the urea cycle for safe renal excretion.
CPN CPN Nutrient Metabolism & Physiology 1
Which amino acid is considered essential for cats because they cannot synthesize adequate amounts from cysteine and methionine?