Plasma Membrane Structure

Q. According to the fluid mosaic model, the quasi-fluid nature of lipid enables lateral movement of protein within the overall, lipid bilayer. This ability to move within the membrane is measured as its

1. Fluidity
2. Movability
3. Mobility
4. All of the above

Q.

What are anchoring and recognition proteins?

Q.

Phospholipids are important cell membrane constituents because they

A. Contain glycerol

B. Combine covalently with proteins

C. Contain both polar and non polar portions

D. Can form bilayers in water

Q.

Question 11

Which of the following statement is not true for plasma membrane?

(a) It is present in both plant and animal cell

(b) Lipid is present as a bilayer in it

(c) Proteins are present integrated as well as loosely associated with the lipid bilayer

(d) Carbohydrate is never found in it

Q. Select the correct statement from the following regarding plasma membrane

1. Lipids are arranged in a bilayer with polar heads towards the inner part.
2. Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.
3. Na+ and K+ ions move across cell membrane by passive transport.
4. Proteins make up 60 to 70% of the cell membrane

Q. Permeability of the axolemma to potassium ions is higher than its permeability to sodium because

1. potassium ions move faster than sodium ions
2. potassium ions are smaller than sodium ions
3. potassium leakage channels are leakier than sodium leakage channels
4. sodium leakage channels are leakier than potassium leakage channels

Q.

Plasma membrane controls

1. Passage of H₂O

2. Passage of water and some solutes into and out of the cell

3. Passage of water and solutes into the cell

4. Passage of cell contents out of the cell

Q. The axoplasm becomes increasingly negative because of

1. sodium ion efflux from axoplasm to ECF
2. potassium ion efflux from axoplasm to ECF
3. chloride ion influx from ECF to axoplasm
4. phosphate influx from ECF to axoplasm

Q. Concentration of sodium ions and chloride ions are comparably higher in

1. extracellular fluid
2. axoplasm
3. axolemma
4. dendrites

Q.

Select the odd one out:

1. The movement of water across a semi-permeable membrane is affected by the amount of substances dissolved in it.

2. Membranes are made of organic molecules like proteins and lipids.

3. Molecules soluble in organic solvents can easily pass through the membrane.

4. Plasma membranes contain chitin sugar in plants.

Q. Which one of the following is not a constituent of cell membrane?

1. Glycolipids
2. Phospholipids
3. Cholesterol
4. Proline

Q. Very thin flexible, living membrane which is differentially permeable, is called................

Q. Assertion :Peripheral proteins are partially or totally buried in the membrane. Reason: Integral proteins lie on the surface of membrane.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. With respect to what basement membrane is permeable because in kidney basement membrane is selectively permeable?

Q. What is an integral membrane protein? What is its function?