Chapter 7 Vocabulary

Question 1

Selective Permeability

Answer 1

Allows some substances to cross it more easily than others

Question 2

Amphipathic Molecule

Answer 2

A molecule with both a hydrophobic region and a hydrophillic region.

Question 3

Fluid Mosaic Model

Answer 3

The membrane is a fluid structure with a “mosaic” of various proteins embedded in or attached to a double layer of phospholipids.

Question 4

Integral proteins

Answer 4

Penetrate the hydrophobic core of the lipid bi-layer, usually trans-membrane proteins

Question 5

Peripheral proteins

Answer 5

Loosely bound into the membrane, usually connected to the exposed parts of integral proteins.

Question 6

Cell recongnition

Answer 6

A cell’s ability to distinguish one type of neighboring cell from another. It is crucial to the functioning of an organism. Glycolipids and glycoproteins are involved in this process.

Question 7

Glyco-

Answer 7

Used to refer to the prescence of carbohydrates

Question 8

Glycolipids

Answer 8

When a carbohydrate is covalently bonded to a lipid or lipids.

Question 9

Glycoproteins

Answer 9

When a carbohydrate is covalently bonded to a protein or proteins.

Question 10

Transport Protein

Answer 10

Function by having a hydrophilic channel that certain molecules or atomic ions can use as a tunnel through the membrane

Question 11

Aquaporins

Answer 11

Channel proteins that allow water to pass through

Question 12

Carrier Proteins

Answer 12

Hold onto their passengers and change shape in a way that shuttles them across the membrane.

Question 13

Diffusion

Answer 13

The tendency for molecules of any substance to spread out evenly into the available space. The molecules will continue to spread across the membrane until both solutions have equal concentrations. From more concentrated to less concentrated.

Question 14

Concentration Gradient

Answer 14

A measurement of how the concentration of something changes from one place to another

Question 15

Passive transport

Answer 15

The diffusion of a substance across a membrane without the use of energy.

Question 16

Hypo-tonic solution

Answer 16

Less salinity, causes the cell to swell

Question 17

Hyper-tonic solution

Answer 17

More salinity, causes the cell to shrink

Question 18

Osmosis

Answer 18

The movement of water across a selectively permeable membrane is called osmosis.

Question 19

Tonicity

Answer 19

The ability of a solution to cause a cell to gain or lose water.

Question 20

Osmoregulation

Answer 20

The control of water balance

Question 21

Turgid

Answer 21

firm

Question 22

Flaccid

Answer 22

Limp

Question 23

Plasmolysis

Answer 23

The cell loses water to its surroundings and shrinks. In a plant, the membrane pulls away from the wall and causes the plant to wilt.

Question 24

Facilitated Diffusion

Answer 24

Molecules and ions pass through the lipid bi-layer with the help of transport proteins with the concentration gradient.

Question 25

Gated channels

Answer 25

A stimulus causes them to open or close, the stimulus can be electrical or chemical.

Question 26

Active Transport

Answer 26

To transport a molecule against the concentration gradient. This requires energy.

Question 27

Sodium-Potassium Pump

Answer 27

Exchanges sodium(Na+) for Potassium(K+) across the plasma membrane of animal cells.

Question 28

Voltage

Answer 28

Electrical potential energy- a separation of opposite charges

Question 29

Membrane Potential

Answer 29

The voltage across the membrane.

Question 30

Electrochemical Gradient

Answer 30

The combination of forces acting on an ion.

Question 31

Electrogenic Pumo

Answer 31

A transport protein that generates voltage across a membrane.

Question 32

Proton Pump

Answer 32

Actively transports H+ out of the cell. The pumping of H+ transfers positive charge from the cytoplasm to the extra-cellular system.

Question 33

Exocytosis

Answer 33

In exocytosis, transport vesicles migrate to the plasma membrane, fuse with it, and release their contents.

Question 34

Endocytosis

Answer 34

Molecules enter cells within vesicles that pinch inward from the plasma membrane. There are three types: phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Question 35

Ligands

Answer 35

A general term for any molecule that binds specifically to a receptor site of another molecule. A complex of a lipid and a protein.