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Question 555
Biochemistry → General
Classification
Question
SSBAQuestion Header
Which protein is most consistent with synthesis on a membrane-bound ribosome rather than a free ribosome?
Question Stem
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Options
A
A protein destined for a mitochondrion
B
A protein destined for a peroxisome
C
Haemoglobin
D
A cytosolic protein
E
A lysosomal protein
Explanation
Ribosomes attached to endoplasmic reticulum synthesise proteins including lysosomal, membrane, enzymatic and hormonal proteins. Free ribosomes synthesise proteins including haemoglobin and proteins destined for mitochondria and peroxisomes.
Option Validity
A) Proteins destined for mitochondria are described as products of free ribosomes.
B) Proteins destined for peroxisomes are described as products of free ribosomes.
C) Haemoglobin is described as a product of free ribosomes.
D) A cytosolic protein does not represent the specifically described bound-ribosome destination tested here.
Further Reading
Saxena - MRCOG-1 Basic Sciences - Biochemistry, printed p.127.