Quick Biochemistry - Proteins And Protein Metabolism (Section 11)
1
A six-amino-acid peptide containing five aspartic acid residues would have a net charge at pH 7:
Answer
(C)
Negative
2
Cystinuria is a genetic disorder where patients excrete large amounts of cystine, leading to kidney stones. Treatment involves consuming NaHCO3. The primary effect of this treatment is
Answer
(C)
NaHCO3 prevents stone formation by breaking down cystine into cysteine
3
In the provided reaction, Alanine behaves as which of the following:
Answer
(C)
Zwitter ion
4
Amino acids (except histidine) are not effective buffers within a cell because
Answer
(C)
Only Histidine's R group has a pKa near 6.0, unlike the others
5
At a neutral pH, the correct structure for Alanine is:
Answer
(B)
6
Which group of amino acids have a net positive charge on their R-groups at pH 7.0?
Answer
(A)
Lysine, Arginine, Histidine
7
Apolipoproteins are classified as
Answer
(D)
All of these
8
Which amino acid has a pKa value close to 4, and therefore carries a negative charge at pH 7?
Answer
(B)
Glutamic acid
9
Which of the following amino acids contains a sulfur atom in its side chain?
Answer
(A)
Methionine
10
Which of the following compounds would yield a positive result when tested with Ninhydrin?
Answer
(C)
Alpha amino acids
11
Besides glutamic acid and cysteine, which other amino acid is found in glutathione (a tripeptide)?
Answer
(B)
Glycine
12
What is the name of the amino acid with the chemical structure 2-Amino 3-OH propanoic acid?
Answer
(D)
Serine
13
Which amino acid does NOT have an asymmetric carbon atom?
Answer
(D)
Glycine
14
Approximately how many amino acids are typically found in plant, animal, and microbial proteins?
Answer
(A)
20
15
What is a key characteristic used to identify immunoglobulins?
Answer
(A)
Heavy chains
16
Which bond within proteins is generally resistant to hydrolysis during typical denaturation processes?
Answer
(C)
Disulphide bond
17
What is the designation for an amino acid where the amino group and carboxylic group are attached to the same carbon atom?
Answer
(A)
Alpha
18
What is a zymogen?
Answer
(D)
An inactivated enzyme
19
What is a typical SGOT level in a healthy adult?
Answer
(A)
5-40 units/dl
20
What type of enzymatic activity does ceruloplasmin exhibit in a laboratory setting?
Answer
(D)
Oxidase
21
Elevated serum alanine during periods without food intake is primarily caused by
Answer
(A)
The breakdown of proteins within muscle tissue
22
Which of these amino acids is NOT required for the complete urea cycle?
Answer
(D)
Glycine
23
How many amino acids are typically found in the proteins consumed through diet?
Answer
(C)
20
24
The primary location where urea synthesis occurs is the
Answer
(B)
Liver
25
Which of the following amino acids does NOT have a primary role in forming ketone bodies?
Answer
(D)
Glycine
26
Which amino acid is characterized by the presence of an indole ring structure?
Answer
(A)
Tryptophan
27
The conversion of Histidine to histamine involves what process?
Answer
(B)
Decarboxylation
28
In what form do amino acids typically exist in a biologically functional state?
Answer
(A)
L
29
Cystine is formed from which amino acid precursor?
Answer
(A)
Cysteine
30
The protein of hair and skin keratin primarily contains a high amount of which amino acid?
Answer
(B)
Cysteine
31
What is the primary process for removing ammonia (NH3) from the brain?
Answer
(D)
Glutamine synthesis
32
What mechanism primarily eliminates ammonia (NH3) from the kidneys?
Answer
(D)
Not applicable
33
Which component is most abundant in low-density plasma proteins?
Answer
(B)
Cholesterol
34
What type of proteins are transcortins?
Answer
(A)
Mucoproteins
35
Which protein is responsible for transporting iron to various tissues?
Answer
(B)
Transcortin
36
What is the typical configuration of naturally occurring amino acids?
Answer
(A)
L-Configuration
37
Which chain in sickle cell anemia contains an abnormal sequence of amino acids?
Answer
(B)
β-chain
38
A deficiency in tryptophan and nicotinate in the diet can cause which condition?
Answer
(D)
Pellegra
39
Which of the following amino acids is considered essential?
Answer
(C)
Phenylalanine
40
Which of the following amino acids exclusively yields ketone bodies during metabolism?
Answer
(A)
Lysine
41
Besides CO2, NH3, and ATP, which amino acid is essential in the urea cycle?
Answer
(C)
Aspartate
42
At what pH does an amino acid exhibit a net neutral charge, considering its isoelectric point?
Answer
(C)
No charge
43
Which substance provides nitrogen atoms for both purine and pyrimidine ring structures?
Answer
(A)
Aspartate
44
Which amino acid assists in the breakdown and transport of fats?
Answer
(D)
Methionine
45
Which protein is known for its high cysteine content?
Answer
(D)
Keratin
46
In the altered hemoglobin variant Hbs, what amino acid replaces glutamate at the sixth position of the β-chain compared to HbA?
Answer
(B)
Valine
47
Which amino acid includes an indole group within its structure?
Answer
(D)
Tryptophan
48
When forming a peptide bond between two amino acids, what molecule is released?
Answer
(A)
Water
49
What term is used for polymers composed of over 100 amino acids?
Answer
(A)
Proteins
50
Which of the following is an example of a globulin?
