Nitrogen Metabolism
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Lecture 63Biochemistry spring 2010SGU
- 1.Compounds that contain nitrogen: proteins, derivatives of amino acids: creatine, ________, purines and pyrimidines, hemeslide 2
- 2.The most important source of amino acids for the amino acid pool is dietary ____ digestion (60-100 g/day)slide 4
- 3.Amino acids are used in amino acid catabolism and in the _______ of nitrogen containing compounds.slide 4
- 4.The rate of tissue protein synthesis is equal to the rate of protein ________. slide 5
- 5.In a healthy, well-fed adult, input of amino acids = _____ of amino acids. The amino acid pool is in a steady state / equilibrium. 6
- 6.Damaged or unneeded proteins are degraded by two mechanisms: the lysosomal pathway that degrades extracellular proteins and the ubiquitin-______ pathway that degrades proteins synthesized by the cell 7
- 7.ATP dependent 8
- A.
Ubiquitin-proteasome pathway
- B.
Lysosomal pathway
- 8.Degrades plasma proteins and proteins taken up by endocytosis 8
- A.
Ubiquitin-proteasome pathway
- B.
Lysosomal pathway
- 9.Non-energy dependent degradative pathway 8
- A.
Ubiquitin-proteasome pathway
- B.
Lysosomal pathway
- 10.Positive nitrogen balance: Intake of dietary nitrogen is ___ the output of nitrogen 11
- A.
Less than
- B.
Greater than
- 11.Increased tissue protein synthesis
- A.
Positive nitrogen balance
- B.
Negative nitrogen balance
- 12.Increase in urinary excretion of urea 12
- A.
Positive nitrogen balance
- B.
Negative nitrogen balance
- 13.Seen in starvation, chronic illness (infections), cancer, uncontrolled diabetes mellitus 12
- A.
Positive nitrogen balance
- B.
Negative nitrogen balance
- 14.During growth periods during childhood and adolescence, pregnancy 11
- A.
Positive nitrogen balance
- B.
Negative nitrogen balance
- 15.Which of the following statements is true? 13
- A.
All amino acids are glucogenic
- B.
All amino acids are essential amino acids
- C.
Amino acid catabolism is increased during starvation
- D.
The major excretory end product of amino acid catabolism is ammonia
- E.
Tissue protein synthesis is decreased during periods of growth
- 16.In infection, the liver synthesizes a group of proteins known as the ____-phase proteins. C-reactive protein, serum amyloid A protein, haptoglobin, ceruloplasmin levels are increased in circulation in any type of inflammation. 15
- 17.____ is the site where most of the amino acids release their amino groups as ammonia 16
- 18.____ is the major end product of nitrogen metabolism 16
- 19.The carbon skeletons of the amino acids are used for __________. 16
- 20.Urea formed in the liver is transported to the kidneys, where it is excreted in the urine. The kidneys also excrete ammonia as ammonium ions. The other non-protein nitrogenous substances that are excreted by the kidney are creatinine and _____ acid. 17
- 21.In a patient with renal disease, which of the following parameters would be the best indicators of renal function? 19
- A.
Serum ammonia
- B.
Serum albumin
- C.
Blood glucose
- D.
Serum free fatty acids
- E.
Blood urea nitrogen
- 22.Tubular reabsorption of cystine is decreased due to an inherited deficiency of the cystine transporter. Cystine is excreted in urine and tends to precipitate in the renal tubules in the renal tract - one of the causes of renal ____ in children 21.
- 23.Hartnup's disease - inherited defect in the transport of the ___ amino acids like tryptophan 22
- 24._____ supplements can be used as treatment for pellagra 22
- 25.Niacin deficiency's 3 d's: dermatitis, diarrhea, and ______. 23
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