Deck 10: Proteins

Question 1

The following can be said of naturally food-derived amino acids after absorption:

A) they have all been derived from protein
B) they inevitably become neurotransmitters
C) they are capable of energy provision
D) they are all essential for life
E) they are nutritionally unavailable from plant foods

Answer 1

D

Question 2

Which of the following statements is FALSE?

A) Every amino acid has a basic amino (-NH2) and an acidic carboxyl (-COOH) group as part of its chemical structure.
B) An amino acid is essential or indispensable if it cannot be synthesised in the human body and must be obtained from the diet.
C) An amino acid is non-essential or dispensable if it can be synthesised. Even if some can be synthesised under stressful circumstances.
D) Most dietary protein is broken down in the stomach, and the end-products, amino acids and short-chain peptides, are absorbed in the small intestine.
E) Proteolytic enzymes produced by the pancreas can digest the pancreas itself, so they are secreted as zymogens, activated when they reach the gastrointestinal lumen.

Answer 2

C

Question 3

Which of the following statements is FALSE?

A) The basis of essential amino acid requirements is that they must be replaced from the diet given that their breakdown products are continually excreted.
B) Protein turnover reflects the balance between its synthesis and breakdown. Children have faster protein turnovers than adults because growth requires protein synthesis.
C) Patients with severe injuries or wasting diseases are said to be in negative nitrogen balance.
D) Protein malnutrition does not occur in humans if there are adequate fat stores for energy needs
E) A person following a vegan or vegetarian diet should eat a varied diet of plant-based foods to get the required range of amino acids.

Answer 3

D

Question 4

Which of the following statements is FALSE?

A) Kwashiorkor is a form of severe malnutrition in children who have received insufficient energy intake but with sufficient protein consumption.
B) Higher intakes of protein are recommended for older adults aged 70 years and over due to their increased need for maintenance.
C) In Australia and New Zealand, protein-energy malnutrition (PEM) is commonly seen in the elderly.
D) It is recommended that the intakes of individual amino acids (as supplements) should not exceed those normally found in the diet.
E) The pattern of essential amino acids is important in the estimation of protein quality.

Question 5

Which of the following is NOT a function of protein?

A) Proteins in cell membranes allow transport of water in and out of cells.
B) Enzymes which act as catalysts in biochemical reactions.
C) Antibodies which neutralise foreign proteins and pathogens such as pathogenic bacteria and viruses.
D) Proteins and amino acids can be metabolised to yield energy.
E) Metalloproteins such as transferrin for iron and ceruloplasmin for copper promote absorption of their corresponding minerals.

Question 6

In steady state conditions, tissue protein breakdown inevitably leads to:

A) the production of uric acid
B) the production of urea
C) altered glycaemic status
D) reduced muscle mass
E) an antibody response

Question 7

Which of the following statements is FALSE?

A) Food products with a high protein content are therefore of high nutritional quality.
B) Proteins of animal-derived food products generally have a higher nutritional quality than those of plant foods.
C) The Digestible Indispensable Amino Acid Score (DIAAS) can be used to differentiate protein sources by their ability to supply amino acids for physiological use.
D) Vegetarian diets can have a nutritionally complete amino acid composition.
E) The criteria for protein requirements vary from conception to later life.

Question 8

All foods or dishes in the following list constitute good quality protein sources:

A) egg, tossed salad, legumes
B) bread and butter, dried beans, meat
C) whole soy drinks, chicken, chickpeas
D) milk, cheese, mushrooms
E) boiled rice, fish, yoghurt

Question 9

How are amino acids classified and how is this relevant to their distribution in food?

Question 10

What factors make the determination of human protein requirements difficult?

Question 11

What are zymogens and why are they important in the digestion of proteins?

Question 12

Why are the digestibility and availability of amino acids important in the assessment of protein quality?