Exam(Elaborations) UNE Biochemistry Unit 4 – Final 2024

Exam(Elaborations) UNE Biochemistry Unit 4 – Final 2024 Which of the following amino acids is considered non essential because it is generated by the urea cycle? A. arginine B. lysine C. asparagine D. glutamine E. histidine arginine The urea cycle takes place in which of the following subcellular locations? A. the cytosol and the mitochondria B. the mitochondria only C. the cytosol only the cytosol and the mitochondria Ubiquitination is a means of targeting a protein for which of the following cellular proceses? A. Digestion B. Proteasomal degradation C. Storage D. Protein translation Proteasomal degradation The reaction of ammonia with α-ketoglutarate is catalyzed by _________ and requires _________ as a reactant. A. glutamate dehydrogenase; ATP B. glutamate dehydrogenase; NADH or NADPH C. glutamate synthetase; NADH or NADPH D. glutamate synthetase; ATP glutamate dehydrogenase; NADH or NADPH Most enzymes involved in protein digestion require cleavage for activation. These proteins are secreted as inactive protein forms called: A. zymogens B. unfolded polypeptides C. dimers D. activated forms zymogens Which of the following enzymes is regulated by N-acetyl glutamate (NAGs)? A. CPS II B. ornithine transcarbamylase C. arginosuccinate lyase D. CPS I CPS I Which of the following enzymes will be active in both the fed and fasted states? A. Glutaminase B. Pyruvate kinase C. Hormone sensitive lipase D. Glycogen synthase Glutaminase Which of the following enzymes is correctly paired with its activator? A. N-acetylglutamate synthtase; arginine B. Carbamoyl phosphate synthetase I; ATP C. Glutaminase; citrate D. arginase; NADH N-acetylglutamate synthtase; arginine Which of the following statements is consistent with nitrogen transport in the fasted state? A. Glutaminase will be active B. The urea cycle will be inactive C. Hepatic glutamate dehydrogenase will primarily produce glutamate D. Transport of alanine from skeletal muscle will be reduced. Glutaminase will be active In the case of a urea cycle deficiency, which of the following amino acids may become essential? A. glutamine B. arginine C. alanine D. aspartate arginine The glucose alanine cycle is a method of transferring ammonia from the skeletal muscle to the liver. In this process the non-toxic carrier of ammonia is which of the following compounds? A. glutamine B. pyruvate C. alanine D. urea alanine Pepsinogen is activated by which of the following mechanisms or enzymes? A. Pepsinogen is activated by trypsin B. Pepsinogen is activated by enteropeptidase C. A change in pH catalyzes the activation of pepsinogen to pepsin D. Pepsinogen is activated by elastase A change in pH catalyzes the activation of pepsinogen to pepsin The process of autophagy is defined as which of the following processes? A. Recycling of proteins under conditions of cellular need or starvation B. Ubiquitin mediated protein degradation C. Protein synthesis D. Cellular lysis or apoptosis Recycling of proteins under conditions of cellular need or starvation When is the process of autophage most likely occurring within the cell? A. When there is low energy in the cell ; ratio of AMP/ATP is 1 B. When there is high energy in the cell ; ratio of AMP/ATP 1 C. When insulin is high D. When mTOR is active When there is low energy in the cell ; ratio of AMP/ATP is 1 The pancreatic zymogen trypsinogen is activated by which of the following enzymes or compounds? A. Enteropeptidase B. HCO3- C. Trypsin D. H+ Enteropeptidase Which of the following reactions takes place in the mitochondria? A. the synthesis of carbamoyl phosphate B. the synthesis of arginine C. the synthesis of argininosuccinate D. the synthesis of urea the synthesis of carbamoyl phosphate Which of the following enzymes is the regulatory step in the urea cycle? A. Arginase B. Ornithine transcarbamoylase C. Carbamoyl phosphate synthetase I (CPS I) D. Arginosuccinate lyase Carbamoyl phosphate synthetase I (CPS I)