What is the name of protein which is found in nail, hair, and horns?
A.
Myoglobin
B.
Hemoglobin
C.
Keratin
D.
Collagen
Answer: Option C
Explanation:
Keratin is the fibrous protein present in the eukaryotes. They have been further classified into α-keratin and β-keratin, in which α-keratin is tough and insoluble and constitute almost the entire dry weight of hair, wool, nail, claws, horn, hooves etc.
In which iron(Fe) state myoglobin binds to the oxygen?
A.
Fe2+
B.
Fe3+
C.
Fe
D.
Fe4+
Answer: Option A
Explanation:
Myoglobin only in the Fe2+ state can bind with oxygen as the iron atom has six co-ordination bonds, 4 in the flat and two in a perpendicular state to the porphyrin ring. The oxygen binding site is present on the other side of six coordination position.
What is the shape of the oxygen dissociation curve of myoglobin?
A.
Linear
B.
Hyperbola
C.
Sigmoid
D.
Parabola
Answer: Option B
Explanation:
Oxygen affinity in myoglobin is more than hemoglobin, as myoglobin binds oxygen more tightly than hemoglobin due to this hemoglobin shows sigmoidal curve while myoglobin shows hyperbolic.
Which of these are the possible cause of sickle cell anemia with respect to hemoglobin?
A.
Defect in β-chain of hemoglobin
B.
Defect in α-chain of hemoglobin
C.
One copy of an abnormal β-globin gene
D.
Two copies of an abnormal β-globin gene
Answer: Option D
Explanation:
If a person has one copy of abnormal β-globin gene it will show sickle cell trait but not sickle cell anemia while an individual with sickle cell anemia has both the copies of an abnormal β-globin gene.
