Cell membrane, also called plasma membrane, thin membrane that su… - Vidyadip

Question

Cell membrane, also called plasma membrane, thin membrane that surrounds every living cell, delimiting the cell from the environment around it. Enclosed by this cell membrane are the cell’s constituents, large, water-soluble, highly charged molecules such as proteins, nucleic acids, carbohydrates, and substances involved in cellular metabolism. Cell membranes are composed primarily of fatty-acid based lipids and proteins. Membrane lipids are principally of two types, phospholipids and sterols (generally cholesterol). Both types share the defining characteristic of lipids—they dissolve readily in organic solvents—but in addition they both have a region that is attracted to and soluble in water.

(1).Plasma membrane is made up of
(a) A protein, a lipid and a cellulose layer
(b) Bimolecular lipid layer surrounded by protein layers
(c) A protein layer between two lipid layers
(d) A lipid layer between two protein layers

(2) Fluid mosaic model of cell was put forward by –
(a) Danielli and Dawson
(b) Singer and Nicolson
(c) Garner and Allard
(d) Watson and Crick

(3) Which of the following statements best describes the chemical composition of
plasma-membrane?
(a) Plasma membrane is composed of two layers—one layer of phospholipids and one layer
of proteins.
(b) Plasma membrane is composed of equal numbers of phospholipids, proteins, and
carbohydrates.
(c) Plasma membrane is bilayers of proteins with associated lipids and carbohydrates.
(d) Plasma membrane is bilayers of phospholipids with associated proteins and
carbohydrates.

(4) Most abundant lipid in the cell membrane is
(a) phospholipids (b) cerebrosides (c) glycolipids (d) None of these

✓

Answer

(1 - B), (2 - B), (3 - D), (4 - A), (5 - A)

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