Vocabulary for Unit 7

Question 1

Amphipathic

Answer 1

Containing hydrophilic and hydrophobic elements.

Question 2

Integral membrane protein

Answer 2

Any membrane protein that spans the entire lipid bilayer. Also called transmembrane protein.

Question 3

Peripheral membrane protein

Answer 3

Any membrane protein that does not span the entire lipid bilayer and associates with only one side of the bilayer.

Question 4

Lipid anchored protein

Answer 4

A covalently attached fatty acid serves to anchor the protein to either face of the cell membrane.

Question 5

Transmembrane

Answer 5

To span the entire lipid bilayer

Question 6

Glycoprotein

Answer 6

Any protein with one of more covalently bonded carbohydrate groups.

Question 7

Detergent

Answer 7

A type of small amphipathic molecule used to solubilize hydrophobic molecules in aqueous solution.

Question 8

Membrane permeability

Answer 8

A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.

Question 9

Diffusion

Answer 9

Spontaneous movement of a substance from a region of high concentration to one of low concentration (i.e., down a concentration gradient)

Question 10

Osmosis

Answer 10

Diffusion of water across a selectively permeable membrane from a region of high water concentration (low solute concentration) to a region of low water concentration (high solute concentration).

Question 11

Passive diffusion

Answer 11

The diffusion of a substance across a plasma membrane or organelle membrane.

Question 12

Active transport

Answer 12

The movement of ions or molecules across a plasma membrane or organelle membrane against an electrochemical gradient. Requires energy (e.g. from hydrolysis of ATP) and assistance of a transport protein (e.g., pump).

Question 13

Pump

Answer 13

Any membrane protein that can hydrolyze ATP to power active transport of a specific ion or small molecule across a plasma membrane against its electrochemical gradient.

Question 14

Na+/K+ pump

Answer 14

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Question 15

Na+/K+ pump

Answer 15

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Question 16

Symport

Answer 16

a mechanism of transporting two compounds simultaneously across a cell membrane in the same direction, one compound being transported down a concentration gradient, the other against a gradient.

Question 17

Antiport

Answer 17

a mechanism of coupling the transport of two compounds across a membrane in opposite directions.