Chapter 7-10

Question 1

Selective permeability

Answer 1

Allowing some substances to cross it more easily than others

Question 2

Phospholipids

Answer 2

Amphipathic molecules containing hydrophobic and hydrophilic regions

Question 3

Fluid mosaic model

Answer 3

A membrane us a fluid structure with a “mosaic” of various proteins embedded in it

Question 4

Most of the lipids, and some proteins drift _____

Answer 4

Laterally

Question 5

As temperatures cool, membranes switch from a fluid state to a ____

Answer 5

Solid state

Question 6

Membranes rich in ________ fatty acids are more fluid

Answer 6

Unsaturated

Question 7

At warm temperatures cholesterol _______ movement of phospholipids

Answer 7

Restrains

Question 8

At cool temperatures, cholesterol ______ fluidity by preventing tight packing

Answer 8

Maintains

Question 9

_______ determine most of the membrane specific functions

Answer 9

Proteins

Question 10

Proteins bound to the surface of the membrane

Answer 10

Peripheral proteins

Question 11

Proteins that penetrate the hydrophobic core

Answer 11

Integral proteins

Question 12

Integral proteins that span the membrane

Answer 12

Transmembrane proteins

Question 13

_______ molecules can dissolve in the lipid bilayer and pass through the membrane rapidly

Answer 13

Hydrophobic (nonpolar)

Question 14

________ molecules do not cross the membrane easily

Answer 14

Polar

Question 15

Proteins that allow passage of hydrophilic substances across the membrane

Answer 15

Transport proteins

Question 16

Type of transport protein, has a hydrophilic channel that certain molecules or ions can use as a tunnel

Answer 16

Channel proteins

Question 17

Channel proteins that facilitate the passage of water

Answer 17

Aquaporins

Question 18

Other transport proteins, Bind to molecules and change shake to shuttle them across the membrane

Answer 18

Carrier proteins

Question 19

A transport protein is ______ for the substance it moves

Answer 19

Specific

Question 20

The tendency for molecules to spread out evenly into the available space

Answer 20

Diffusion

Question 21

As many molecules cross one way as crows in the other direction

Answer 21

At dynamic equilibrium….

Question 22

Substances diffuse down their own ______

Answer 22

Concentration gradient

Question 23

The diffusion of a substance across a biological membrane, no energy is required

Answer 23

Passive transport

Question 24

The diffusion of water across a selectively peremeable membrane

Answer 24

Osmosis

Question 25

Water diffuses across a membrane from the region of _____ solute concentration to the region of _____ solute concentration

Question 26

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

Answer 26

Tonicity

Question 27

Solute concentration is the same as that inside the cell, no net water movement across the plasma membrane

Answer 27

Isotonic solution

Question 28

Solute concentration is greater than that inside the cell, cell loses water

Answer 28

Hypertonic solution

Question 29

solute cocnentrwfiom is less than that inside the cell, cell gains water

Answer 29

Hypotonic solution

Question 30

the control of water balance

Answer 30

Osmosregulation

Question 31

Transport proteins speed the passive movement of molecules across the plasma membrane

Answer 31

Facilitated diffusion

Question 32

Channel proteins include:

Answer 32

Aquaporins Ion channels

Question 33

Transport proteins move solutes against their concentration gradient, requires energy (in the form of ATP), allows cells to maintain concentration gradients that differ from their surroundings

Answer 33

Active transport

Question 34

The Voltage across a membrane

Answer 34

Membrane potential

Question 35

Is created by differences in distribution of positive and negative ions

Answer 35

Voltage

Question 36

The 2 forces (called the electrochemical gradient) drive the diffusion is ions across a membrane:

Answer 36

A chemical force (ion’s concentration gradient) A electrical force (effect of the membrane potential in the ion’s movement)