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Cell Membrane (AIPVT)

Description: proteins
Number of Questions: 15
Created by:
Tags: cell membrane Cell Membrane
Attempted 0/15 Correct 0 Score 0

Which of the following is/are pumped across the membrane by transmembrane transporters?

  1. Solid particles

  2. Amino acids

  3. Sodium

  4. CO2


Correct Option: B
Explanation:

Amino acids are large molecules which are pumped across the membrane by transmembrane transporters.

How are small molecules like CO2 and O2 transported across the membrane?

  1. By transmembrane protein channels or aquaporins

  2. By passive osmosis

  3. By endocytosis

  4. By pumps


Correct Option: B
Explanation:

Small molecules or ions such as carbon dioxide (CO2) and oxygen (O2) can move across the plasma membrane by passive osmosis.

In which of the following organisms is periplasm found?

  1. Gram positive bacteria

  2. Gram negative bacteria

  3. Eukaryotic animal cell

  4. Eukaryotic plant cell


Correct Option: B
Explanation:

Periplasm is found in Gram negative bacteria. Gram negative bacteria have both a plasma membrane and an outer membrane separated by periplasm.

Besides being selectively permeable, plasma membrane of eukaryotes also functions in

  1. electron transport chain reactions

  2. synthesis of ATP through chemiosmosis

  3. providing rigidity to the cell

  4. providing free permeability to K+, Na+ and chlorine ions


Correct Option: B
Explanation:

Besides being selectively permeable, plasma membrane of eukaryotes also functions in synthesis of ATP through chemiosmosis.

Which of the following molecules is cell membrane impermeable to?

  1. N2

  2. Ethanol

  3. Urea

  4. Glucose-6-phosphate


Correct Option: D
Explanation:

Cell membrane is impermeable to charged polar molecules like glucose-6-phosphate.

What are the small invaginations of plasma membrane in vertebrate cell called?

  1. Invadopodium

  2. Podosome

  3. Caveolae

  4. Postsynaptic density


Correct Option: C
Explanation:

Caveolae are the small invaginations of plasma membrane of many vertebrate cell types, especially in endothelial cells and adipocytes. These are rich in proteins and lipids.

Which of the following supermembrane structures is associated with cellular motility and invasion?

  1. Invadopodium

  2. Podosome

  3. Postsynaptic density

  4. Focal adhesion


Correct Option: B
Explanation:

Podosomes are connected to cellular motility and invasion. Therefore, they serve as sites of attachment and degradation along the extracellular matrix.

Lipid rafts and caveolae microdomains of the cell membrane are rich in

  1. prenol lipids

  2. cholesterol

  3. saccharolipids

  4. polyketides


Correct Option: B
Explanation:

Lipid rafts and caveolae microdomains of the cell membrane are rich in cholesterol.

The actin-based filaments formed by cytoskeleton in order to sense the external environment are called

  1. cilia

  2. filopodia

  3. microvilli

  4. blebs


Correct Option: B
Explanation:

The actin-based filaments formed by cytoskeleton in order to sense the external environment are called filopodia. They are rich in actin-binding proteins, e.g. fascin and fimbrin. Filopodia are slender cytoplasmic projections that form focal adhesion with the substrate linking it to the cell surface.

Cell membrane of myocytes is known as

  1. oolemma

  2. sarcolemma

  3. axolemma

  4. plasmalemma


Correct Option: B
Explanation:

Cell membrane of myocytes is known as sarcolemma. It consists of a plasma membrane, which is a lipid bilayer, and an outer coat consisting of a thin layer of polysaccharide material (glycocalyx) that contacts the basement membrane, which contains numerous thin collagen fibrils and specialized proteins such as laminin that provide a scaffold for the muscle fiber to adhere to it.

In sodium-potassium pump, the event of dephosphorylation occurs when

  1. 3 Na+ ions bind to the active site of the pump

  2. 2 molecules of K+ bind to the pump at their respective binding sites

  3. hydrolysis of ATP takes place after Na+ ions bind to ATP

  4. K+ ions are transported into the cell


Correct Option: B
Explanation:

When the pump binds two molecules of K+ to their respective bonding sites on the extracellular face of the transport protein, dephosphorylation of the pump occurs.

Which of the following are an example of lipid-anchored proteins?

  1. Hormones

  2. G-proteins

  3. Pump proteins

  4. G-protein coupled receptors


Correct Option: B
Explanation:

G-proteins are an example of lipid-anchored proteins. G-proteins act as molecular switches inside the cell and are involved in transmitting signals from a variety of stimuli outside a cell to its interior.

Which of the following membranes has the highest amount of proteins?

  1. Inner mitochondrial membrane

  2. Erythrocyte membrane

  3. Outer mitochondrial membrane

  4. Myelin sheath membrane


Correct Option: A
Explanation:

The inner mitochondrial membrane is very rich in proteins. It contains proteins in the form of enzymes required for electron transport chain.

Fluid mosaic model about the structure and function of membrane was given by

  1. Alfred G. Gilman and Martin Rodbell

  2. Singer and Nicolson

  3. Harvey and Danielli

  4. Davson and Danielli


Correct Option: B
Explanation:

Fluid mosaic model about the structure and function of membrane was given by Singer and Nicolson in 1972.

Which of the following lipids are not present in cell membrane?

  1. Phospholipids

  2. Glycolipids

  3. Sterols

  4. Sphingolipids


Correct Option: D
Explanation:

Sphingolipids are not found in cell membrane.

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