Membranes

Question 1

What makes up a plasma membrane?

Answer 1

• Lipids
• Proteins
• Carbohydrates

Question 2

The one class of large biological molecules that does not include true polymers

Answer 2

Lipids

Question 3

Fats are comprised of

Answer 3

• Glycerol
• Fatty Acids

Question 4

A carboxyl group attached to a long carbon skeleton

Answer 4

Fatty Acid

Question 5

____fatty acids have the maximum number of hydrogen atoms possible and no double bonds

Answer 5

Saturated

Question 6

____ fatty acids have one or more double bonds

Answer 6

Unsaturated

Question 7

Two fatty acids and a phosphate group, attached to glycerol, make a

Answer 7

phospholipid

Question 8

What is an amphipathic molecule?

Answer 8

Contains hydrophilic and hydrophobic regions

Example: phospholipids

Question 9

Lipids characterized by a carbon skeleton consisting of four fused rings

Answer 9

Steroids

Question 10

A precursor from which other steroids are synthesized

Answer 10

Cholesterol

Question 11

____ proteins are bound to the surface of the membrane

Answer 11

Peripheral

Question 12

____ proteins penetrate the hydrophobic core

Answer 12

Integral

Question 13

These are examples of

• Transport
• Enzymatic activity
• Signal transduction
• Cell-cell recognition
• Intercellular joining
• Attachment to the cytoskeleton and extracellular matrix (ECM)

Answer 13

Functions of membrane proteins

Question 14

____ allow passage of hydrophilic substances across the membrane

Answer 14

Transport proteins

Question 15

Channel proteins that facilitate the passage of water molecules

Answer 15

aquaporins

Question 16

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

Answer 16

Diffusion

Question 17

Diffusion across a membrane with no energy investment

Answer 17

Passive Transport

Question 18

The diffusion of water across a selectively permeable membrane

Answer 18

Osmosis

Question 19

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

Answer 19

Tonicity

Question 20

No net water movement across the plasma membrane

Answer 20

Isotonic Solution

Question 21

Hypertonic Solution

Answer 21

Cell loses water

Question 22

Hypotonic Solution

Answer 22

Cell takes on water

Question 23

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

Answer 23

Facilitated Diffusion

Question 24

What do ion channels do?

Answer 24

Help shuttle ions across a cell membrane

Question 25

____ allows cells to maintain concentration gradients that differ from their surroundings

Answer 25

Active Transport

Uses ATP

Question 26

A transport protein that is energized by transfer of a phosphate group from the hydrolysis of ATP

Answer 26

Sodium-potassium pump

Question 27

What is membrane potential?

Answer 27

The voltage across a membrane

Question 28

What two forces power the electrochemical gradient?

Answer 28

• A chemical force
• An electrical force

Question 29

A transport protein that generates voltage across a membrane

Answer 29

An electrogenic pump

Question 30

A ____ pump actively transports hydrogen ions (H+) out of the cell

Answer 30

proton

Question 31

When active transport of a solute indirectly drives the transport of other substances

Answer 31

Cotransport

Question 32

What happens in exocytosis?

Answer 32

A vesicle vomits its content outside the cell

Example: dead organelles, intruders, general cell trash

Question 33

These are the three types of

• Phagocytosis-cellular eating
• Pinocytosis-cellular drinking
• Receptor-mediated

Answer 33

Endocytosis