LIFE SCIENCE

OBJECTIVE LIFE SCIENCE

CELL BIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
____ has no ribosomes attached to it and is involved in making lipids.
A
ribosome
B
rough endoplasmic reticulum
C
smooth endoplasmic reticulum
D
nucleus
Explanation: 

Detailed explanation-1: -The rough ER, which is covered by ribosomes on its outer surface, functions in protein processing. The smooth ER is not associated with ribosomes and is involved in lipid, rather than protein, metabolism.

Detailed explanation-2: -When proteins are destined to be part of the cell membrane or exported from the cell, the ribosomes assembling them attach to the endoplasmic reticulum, giving it a rough appearance. Smooth endoplasmic reticulum lacks ribosomes and helps synthesize and concentrate various substances needed by the cell.

Detailed explanation-3: -SMOOTH ENDOPLASMIC RETICULUM It is not studded with ribosomes hence ‘smooth’ ER. Smooth ER is devoted almost exclusively to the manufacture of lipids and in some cases to the metabolism of them and associated products.

Detailed explanation-4: -The smooth endoplasmic reticulum functions in many metabolic processes. It synthesizes lipids, phospholipids as in plasma membranes, and steroids. Cells that secrete these products, such as cells of the testes, ovaries, and skin oil glands, have an excess of smooth endoplasmic reticulum.

Detailed explanation-5: -The smooth ER is important in the synthesis of lipids, such as cholesterol and phospholipids, which form all the membranes of the organism. In addition it is important for the synthesis and secretion of steroid hormones from cholesterol and other lipid precursors. In addition, it is involved in carbohydrate metabolism.

There is 1 question to complete.