PROTEIN AND NITROGEN METABOLISM: REQUIREMENTS,
BALANCE, AND REGULATION IN HUMANS |COMPLETE
STUDY GUIDE WITH 100% ACCURATE QUESTIONS
&ANSWERS. EXCELLENCE GUARANTEED.
What is the main takeaway regarding protein metabolism? Answer: The body maintains
a dynamic balance between protein synthesis and degradation, influenced by dietary
intake, recycling, and losses.
What is the Estimated Average Requirement (EAR) for protein in healthy adults?
Answer: Approximately 0.66 g/kg/day.
What is the Recommended Dietary Allowance (RDA) for protein in healthy adults?
Answer: 0.8 g/kg/day.
What are the two main sources of nitrogen for amino acids? Answer: Exogenous
(dietary) and endogenous (body-derived) sources.
How much protein does the body degrade daily? Answer: Approximately 400 g of
protein.
What is the primary form of nitrogen loss in the body? Answer: Urea, excreted by the
kidneys.
What is deamination? Answer: The removal of the nitrogen group (NH₃) from amino
acids, resulting in a keto group and ammonia.
What is the role of the urea cycle? Answer: To convert ammonia into urea for excretion
by the kidneys.
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
, What is protein turnover? Answer: The balance between protein synthesis and
degradation.
What is the purpose of protein degradation? Answer: To remove oxidized, damaged, or
misfolded proteins and adapt protein levels to physiological needs.
What occurs during transcription in protein synthesis? Answer: RNA polymerase II
transcribes mRNA, which is then processed before translation.
What is the function of tRNAs during translation? Answer: tRNAs bind to mRNA and
bring amino acids to form peptide bonds.
What is the ubiquitin-proteasome degradation pathway? Answer: A process where
ubiquitin tags proteins for degradation by the proteasome.
What is autophagy? Answer: A mechanism for degrading intracellular material by fusing
it with lysosomes.
Which hormone promotes protein synthesis and inhibits breakdown? Answer: Insulin.
What effect does cortisol have on protein metabolism? Answer: It increases protein
degradation and inhibits protein synthesis.
What is the role of the mechanistic target of rapamycin (mTOR)? Answer: It regulates
cellular growth, metabolism, and survival by integrating various signals.
What activates mTORC1? Answer: Glucose, amino acids (especially leucine), insulin,
IGF-1, and inflammation.
What are the consequences of mTORC1 overactivation? Answer: It can lead to insulin
resistance and conditions like Tuberous Sclerosis.
What is the main nitrogen loss through feces? Answer: Small amounts of undigested or
unabsorbed protein.
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
BALANCE, AND REGULATION IN HUMANS |COMPLETE
STUDY GUIDE WITH 100% ACCURATE QUESTIONS
&ANSWERS. EXCELLENCE GUARANTEED.
What is the main takeaway regarding protein metabolism? Answer: The body maintains
a dynamic balance between protein synthesis and degradation, influenced by dietary
intake, recycling, and losses.
What is the Estimated Average Requirement (EAR) for protein in healthy adults?
Answer: Approximately 0.66 g/kg/day.
What is the Recommended Dietary Allowance (RDA) for protein in healthy adults?
Answer: 0.8 g/kg/day.
What are the two main sources of nitrogen for amino acids? Answer: Exogenous
(dietary) and endogenous (body-derived) sources.
How much protein does the body degrade daily? Answer: Approximately 400 g of
protein.
What is the primary form of nitrogen loss in the body? Answer: Urea, excreted by the
kidneys.
What is deamination? Answer: The removal of the nitrogen group (NH₃) from amino
acids, resulting in a keto group and ammonia.
What is the role of the urea cycle? Answer: To convert ammonia into urea for excretion
by the kidneys.
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
, What is protein turnover? Answer: The balance between protein synthesis and
degradation.
What is the purpose of protein degradation? Answer: To remove oxidized, damaged, or
misfolded proteins and adapt protein levels to physiological needs.
What occurs during transcription in protein synthesis? Answer: RNA polymerase II
transcribes mRNA, which is then processed before translation.
What is the function of tRNAs during translation? Answer: tRNAs bind to mRNA and
bring amino acids to form peptide bonds.
What is the ubiquitin-proteasome degradation pathway? Answer: A process where
ubiquitin tags proteins for degradation by the proteasome.
What is autophagy? Answer: A mechanism for degrading intracellular material by fusing
it with lysosomes.
Which hormone promotes protein synthesis and inhibits breakdown? Answer: Insulin.
What effect does cortisol have on protein metabolism? Answer: It increases protein
degradation and inhibits protein synthesis.
What is the role of the mechanistic target of rapamycin (mTOR)? Answer: It regulates
cellular growth, metabolism, and survival by integrating various signals.
What activates mTORC1? Answer: Glucose, amino acids (especially leucine), insulin,
IGF-1, and inflammation.
What are the consequences of mTORC1 overactivation? Answer: It can lead to insulin
resistance and conditions like Tuberous Sclerosis.
What is the main nitrogen loss through feces? Answer: Small amounts of undigested or
unabsorbed protein.
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
