NUSCTX 103 Exam 1 – Protein UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Protein in the diet - CORRECT ANSWER - • Need to consume protein daily
- no storage form
- obligate losses of 20-30g/day
- tissue and plasma proteins will be catabolized to make amino acids available to meet body
needs
- must be broken down to provide body with amino acids
• to synthesize new proteins
• oxidized for energy /to prevent toxic levels of individual amino acids
- must be broken down to prevent an immune response
exogenous sources of protein - CORRECT ANSWER - dietary
- Animal products
- Meat, poultry, fish, eggs
- Plant products
- Grains, legumes, nuts/seeds
endogenous sources of protein - CORRECT ANSWER - - Sloughed off cells in the
digestive tract
- Digestive enzymes and secreted proteins
- cellular recycling (lysosomal degradation)
how much dietary protein is lost in feces - CORRECT ANSWER - small amount
, 3-5% of ingested nitrogen
where does protein digestion start - CORRECT ANSWER - in the stomach
parietal cells - CORRECT ANSWER - - HCl secretion
- Mediates protein denaturation
- Induces cleavage andactivation of pepsin
chief cells - CORRECT ANSWER - Secretion of pepsinogen (also gastric lipase)
pepsin features - CORRECT ANSWER - • Pepsin is created as an inactive "pro-enzyme"
called pepsinogen
• Pepsin is activated under acidic conditions, cleaving the additional amino acids to yield the
active enzyme pepsinogen pepsin catalyticsite
• Pepsin is an endopeptidase
- hydrolyzes interiorpeptide bonds within proteins
- Relatively low specify
reduced or absent (achlorhydria) stomach acid - CORRECT ANSWER - - Caused by:
• Excessive use of proton pump inhibitors
• hypothyroidism
• H. pylori infection
• VIPomas- endocrine tumors commonly in the pancreatic beta cell that secrete the hormone
vasoactive intestinal peptide (VIP)
• Damage to parietal cells (e.g. autoantibodies, radiation) - Can compromise nutrient digestion
• Protein malnutrition
• Micronutrients- e.g. Vitamin B12 absorption (from foods where it is protein-bound) is reduced
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ACTUAL Exam Questions and CORRECT
Answers
Protein in the diet - CORRECT ANSWER - • Need to consume protein daily
- no storage form
- obligate losses of 20-30g/day
- tissue and plasma proteins will be catabolized to make amino acids available to meet body
needs
- must be broken down to provide body with amino acids
• to synthesize new proteins
• oxidized for energy /to prevent toxic levels of individual amino acids
- must be broken down to prevent an immune response
exogenous sources of protein - CORRECT ANSWER - dietary
- Animal products
- Meat, poultry, fish, eggs
- Plant products
- Grains, legumes, nuts/seeds
endogenous sources of protein - CORRECT ANSWER - - Sloughed off cells in the
digestive tract
- Digestive enzymes and secreted proteins
- cellular recycling (lysosomal degradation)
how much dietary protein is lost in feces - CORRECT ANSWER - small amount
, 3-5% of ingested nitrogen
where does protein digestion start - CORRECT ANSWER - in the stomach
parietal cells - CORRECT ANSWER - - HCl secretion
- Mediates protein denaturation
- Induces cleavage andactivation of pepsin
chief cells - CORRECT ANSWER - Secretion of pepsinogen (also gastric lipase)
pepsin features - CORRECT ANSWER - • Pepsin is created as an inactive "pro-enzyme"
called pepsinogen
• Pepsin is activated under acidic conditions, cleaving the additional amino acids to yield the
active enzyme pepsinogen pepsin catalyticsite
• Pepsin is an endopeptidase
- hydrolyzes interiorpeptide bonds within proteins
- Relatively low specify
reduced or absent (achlorhydria) stomach acid - CORRECT ANSWER - - Caused by:
• Excessive use of proton pump inhibitors
• hypothyroidism
• H. pylori infection
• VIPomas- endocrine tumors commonly in the pancreatic beta cell that secrete the hormone
vasoactive intestinal peptide (VIP)
• Damage to parietal cells (e.g. autoantibodies, radiation) - Can compromise nutrient digestion
• Protein malnutrition
• Micronutrients- e.g. Vitamin B12 absorption (from foods where it is protein-bound) is reduced
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