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Quick Biochemistry - Proteins And Protein Metabolism (Section 9)

1
Which metabolite is NOT a direct product of the hexose monophosphate pathway?
Answer
(B)
Dihydroxy acetone phosphate
2
Regarding glucose-6-phosphate dehydrogenase deficiency, which statement is accurate?
Answer
(A)
Young red blood cells, particularly reticulocytes, have higher enzyme activity; other cells show less.
3
The inhibition of glycolysis by oxygen is known as:
Answer
(B)
Pasteur effect
4
Serotonin is synthesized from which amino acid?
Answer
(C)
Tryptophan
5
Which amino acid is considered a lipotropic factor?
Answer
(D)
Methionine
6
Which amino acid is essential for human nutrition?
Answer
(D)
Tryptophan
7
What characterizes essential amino acids?
Answer
(B)
They must be obtained from the diet because humans have a limited ability to synthesize the carbon chains of their corresponding ketoacids.
8
Which of the following amino acids is essential?
Answer
(B)
Leucine
9
Which of the following is a basic amino acid?
Answer
(B)
Arginine
10
Which amino acid lacks optical isomers?
Answer
(D)
Glycine
11
What amino acid features a guanidine functional group?
Answer
(B)
Arginine
12
What is the primary role of GABA (gamma-aminobutyric acid) in the nervous system?
Answer
(B)
Post-synaptic inhibitor transmitter
13
Which amino acid includes sulfur within its structure?
Answer
(C)
Homocysteine
14
Which reagent is commonly employed to identify amino acids?
Answer
(C)
Ninhydrin
15
Which amino acid contains an indole ring within its structure?
Answer
(D)
Tryptophan
16
The Sakaguchi reaction is a specific test that is positive for which amino acid?
Answer
(C)
Arginine
17
What factor influences the pH of an amino acid?
Answer
(B)
Dissociation constant
18
How does the pH of a mixture change when amino acids react with neutral formaldehyde?
Answer
(C)
Decreases
19
Which amino acid incorporates an imidazole group in its structure?
Answer
(A)
Histidine
20
In what type of solution do amino acids typically exist as zwitterions?
Answer
(D)
Neutral solution
21
What method is used to separate plasma proteins?
Answer
(D)
Both precipitation and electrophoresis
22
Following digestion, what is the primary fate of amino acids?
Answer
(A)
Absorption into the portal circulation
23
Which of the following is the correct formula for cysteine?
Answer
(C)
HS-—CH₂-—CH(NH₂)—-COOH
24
The structure represents which compound, with one NH2 group?
Answer
(D)
Citrulline
25
Which amino acid includes a disulphide bond in its structure?
Answer
(D)
Cystine
26
Which of the following amino acids includes a phenolic group in its structure?
Answer
(C)
Seratonine
27
Which amino acid deviates from the typical — COOH group in its structure?
Answer
(D)
Taurine
28
Which group of amino acids are considered branched chain amino acids?
Answer
(D)
Valine, Leucine and Isoleucine
29
What is the characteristic of a Zwitter ion in an aqueous solution?
Answer
(A)
Possessing one positive and one negative charge
30
Which amino acid produces a yellow color when reacted with Ninhydrin in paper chromatography?
Answer
(B)
Proline
31
Which substance facilitates the hydroxylation of Proline and Lysine within a protein?
Answer
(D)
Vitamin C
32
Which amino acid is identified through Millon's test?
Answer
(A)
Tyrosine
33
Which amino acid is identified through Hopkins-Cole test?
Answer
(B)
Tryptophan
34
Which amino acid is a major component of collagen?
Answer
(A)
Glycine
35
Which of the following amino acids lacks optical activity?
Answer
(A)
Glycine
36
Approximately how many of the naturally occurring amino acids are typically found in proteins?
Answer
(A)
20
37
What is the stereochemical form of amino acids produced by the enzymatic hydrolysis of proteins?
Answer
(B)
L
38
How many ionizable groups are present in amino acids as a minimum?
Answer
(B)
2
39
Which amino acid is considered neutral?
Answer
(C)
Leucine
40
Which amino acid contains a hydroxyl group in its structure?
Answer
(D)
Threonine
41
Which of the following amino acids contains sulfur?
Answer
(C)
Methionine
42
Which amino acid is classified as basic?
Answer
(C)
Histidine
43
Which amino acid is a precursor for several hormones?
Answer
(B)
Phenyl alanine
44
Amino acids demonstrate insolubility in which of the following solvents?
Answer
(D)
Benzene
45
What is the primary waste product of protein nitrogen metabolism in humans?
Answer
(C)
Urea
46
Which of the following amino acids is not utilized in the urea cycle?
Answer
(B)
Histidine
47
In the brain, how is ammonia primarily detoxified?
Answer
(D)
Glutamine
48
Where does the detoxification of ammonia predominantly occur in the human body?
Answer
(C)
Urea
49
What is the state of body proteins after a person reaches eighteen years of age?
Answer
(C)
Is in a constant state of flux
50
Which substances are the only physiological methylating agents identified in animal systems?
Answer
(C)
Betaine and 8-adenyosyl methionine