Proteins differ from carbohydrates and lipids in that they contain
D) nitrogen
Of the chemical groups listed below, only a/an________group is not part of all amino acids
C) methyl
A peptide bond is formed when two amino acids are combined by linking one
A) amino group to the acid group of another amino acid
Compared to a protein in its original state, a protein which has been denatured
C) has lost its biological activity
Protein digestion occurs primarily in
B) the small intestine
Pepsin is
B) a gastric enzyme which breaks large polypeptides into smaller polypeptides
Protein digestion in the stomach produces
B) small polypeptides
Pepsinogen is converted to pepsin by
D) hydrocholoric acid
A non-essential amino acid
B) can be produced endogenously if nitrogen and carbohydrate are present
A human adult requires__________essential amino acids
A) 9
A limiting amino acid is
B) the essential amino acid found in shortest supply relative to the amount needed for protein synthesis
Of the factors listed below, only____________does not affect the quality of dietary protein
D) the presence of all amino acids
True/False (support your answer with an explanation)
Incomplete proteins will not be absorbed because of the lack of one or more EAA
False
The absorption of amino acids from the GI tract does not require the presence of all EAA. It is in support of protein synthesis that all EAA must be available simultaneously in the body
___________would complement the protein in dried beans
E) any of the above
Of the functions listed below, only____________is not amoung the general roles of protein
A) storing energy
Proteins are important regulators of acid-base balance because
C) they can function as both acids and bases
Contractile proteins function in
E) muscle function
Hemoglobin functions in
B) oxygen transport
Transferrin functions in
B) iron transport
Insulin functions in
C) blood glucose regulation
Opsin functions in
E) vision
If nitrogen balance is negative,
C) nitrogen output exceeds nitrogen intake
If nitrogen intake is equal to nitrogen output, the subject is
D) consuming enough protein to replace body losses
True/False (support your answer with an explanation)
Negative nitrogen balance occurs in children and pregnant women because they require extra protein
False
Positive nitrogen balance occurs in this situation
Protein deficiency is most commonly seen in Third World countries
B) children
List some of the body systems that are affected in a child when protein intake is insufficient
When a child's protein intake is insufficient, the body systems affected include the muscles (including the heart), the brain, the metabolic system, the system regulating growth, the system regulating fluid balance, the liver, the skin and hair, the immune system, and the blood
Why does PEM most commonly strike newly weaned children?
PEM is most common amoung newly weaned children because their bodies must adjust to a starchy, low-protein diet after having been accustomed to a diet of protein-rich breast milk
True/False (support your answer with an explanation)
As athletes or muscle-builders have higher protein needs than ordinary foods can supply, protein supplements are necessary
False
Although athletes may have a higher protein need than non-athletes, they can easily obtain enough protein through the increased food intake usually consumed for extra energy. Exercise, not protein supplements, stimulates muscle-building
Nutritional concerns are greatest in the diet of
C) vegans
A vegan diet will potentially have the greatest negative impact on the nutritional status of
C) growing children
What micronutrients can potentially be a problem for vegetarians?
-Iron
-zinc
-calcium
-vitamin B-12
-vitamin D
The health benefits of a vegetarian diet include a reduced risk of all of the ailments listed below, except
A) migraine
The ideal level of protein intake is____________of total energy intake for most adults
A) 10-12%
In Canada, protein intake is about_____________of energy intake
C) 16%
The only segment of the Canadian population that may be at risk for dietary protein inadequacy is
