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Question 517
Biochemistry → General
Classification
Question
SSBAQuestion Header
A steroid-secreting cell contains an extensive intracellular membrane system without attached ribosomes. Which function is most closely associated with this organelle?
Question Stem
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Options
A
Synthesis of proteins for secretion outside the cell
B
Processing and labelling proteins before delivery
C
Degradation of phagocytosed macromolecules
D
Synthesis of lipids and steroid hormones
E
Synthesis of ATP by oxidative phosphorylation
Explanation
Smooth endoplasmic reticulum lacks attached ribosomes and is particularly abundant in cells synthesising lipids, phospholipids, lipoproteins and steroid hormones. It also participates in cellular metabolism, calcium storage and metabolism, and detoxification of toxic substances.
Option Validity
A) Protein synthesis for subsequent secretion outside the cell is a function of rough endoplasmic reticulum.
B) Processing, packaging, labelling and delivery of proteins are functions of the Golgi apparatus.
C) Degradation of phagocytosed material is performed by lysosomes after formation of an active secondary lysosome.
E) ATP synthesis by oxidative phosphorylation occurs in mitochondria, with the respiratory chain located on the cristae.
Further Reading
Richa Saxena. Textbook for MRCOG-1: Basic Sciences in Obstetrics & Gynaecology. Biochemistry and Nutrition — Biochemistry — Structure and Function of Normal Cell. Printed pp. 124–125.