Membrane Transport

Question 1

Polar molecules

Answer 1

Such as sugars do not cross the membrane easily

Question 2

Passive transport

Answer 2

Is a diffusion of a substance across a membrane with no energy investment

Question 3

Diffusion

Answer 3

Tendency for molecules to spread out evenly into the available space

Question 4

Dynamic equilibrium

Answer 4

As many molecules cross the membrane in one direction as in the other

Question 5

At higher temperature the diffusion rate is

Answer 5

Greater

Question 6

At a given temperature smaller molecules diffuse faster ?

Answer 6

True

Question 7

Osmosis

Answer 7

Is diffusion of water across a selectively permeable membrane

Question 8

How does water diffuses across a membrane?

Answer 8

from the region of lower solute concentration to region of higher solute concentration until the solute concentration is equal on both sides

Question 9

Hydrophobic (NONPOLAR) molecules

Answer 9

Can dissolve in lipid bilayer and pass through the membrane rapidly

Question 10

Tonicity

Answer 10

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

Question 11

Isotonic solution

Answer 11

Solute concentration is the same as the inside the cell; no net water movement across the plasma membrane.

Question 12

Hypertonic solution

Answer 12

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

Question 13

Hypotonic solution

Answer 13

Solute concentration is less than That inside the cell, cell gains water

Question 14

Plasmolysis

Answer 14

In a hypertonic environment plant cells lose water, eventually the membrane pulls away from the wall a usually lethal effect

Question 15

Active transport requires energy in ur form of

Answer 15

ATP

Question 16

How is active transport performed ?

Answer 16

By specific proteins embedded in the membranes

Question 17

Types of transport

Answer 17

Uniform
Symport
Antiport

Question 18

Uniport

Answer 18

Single substance is moved in single direction

Question 19

2 types of Co transport ?

Answer 19

Symport and antiport

Where 2 different substances are moved together

Question 20

Symport

Answer 20

Two different substances are moved in same direction

Question 21

Antiport

Answer 21

One substance moved in one direction whole another moved in opposite direction

Question 22

Aquaporins

Answer 22

Membrane channels that allow water to cross the membrane

Question 23

Acetylcholine

Answer 23

Neurotransmitter, in the absence of it, the ion channel is closed when present the transporter gets triggered or hated by this small molecule ACh

Question 24

Na+/K+ pump

Answer 24

The sodium potassium pump is essential for active transport in all animal cells but not plants or most microbes

Question 25

Explain the sodium potassium pump

Answer 25

3 Na+ bond to the pump on the cytoplasmic side ATP hydrolysis phosphorylates the pump 2 K+ ions bind to the pump of the extracellular side Phosphate group is released causing a conformational change that releases the K+ ions into the cell The pump is returned to its iriginla conformation and can repeat the cycle

Question 26

Phosphorylation

Answer 26

Causes a conformational change in the pump that releases the Na+ ions out the cell

Question 27

The net effect of Na+ K+ pump is ?

Answer 27

is to increase concentration of Na+ outside the cell and K+ inside the cell. Since both are accumulated against concentration gradients, energy is required from ATP

Question 28

Membrane potential ?

Answer 28

Is the voltage difference across a membrane

Question 29

How is voltage created ?

Answer 29

Is created by the differences in the distribution of positive and negative ions across a membrane

Question 30

Electrochemical gradient?

Answer 30

Two combined forces that drive the diffusion of ions across a membrane

Question 31

A chemical force ?

Answer 31

The ions concentration gradient

Question 32

An electrical force ?

Answer 32

The effect of the membrane potential on the ions movement

Question 33

Electrogenic pump ?

Answer 33

Is a transport protein that generates voltage across a membrane

Question 34

Major electrogenic pump of animal cells?

Answer 34

Sodium-potassium pump

Question 35

Major electrogenic pump of plants fungi and bacteria is ?

Answer 35

Proton pump

Question 36

Secondary active transport

Answer 36

Movement of a substance is indirectly achieved by movement of second substance

Question 37

Exocytosis

Answer 37

Substances are directed out of a cell to be secreated by fusing a vesicle to the cell membrane

Question 38

Substances are shuttled into out of and within a cell through ?

Answer 38

Vesicles

Question 39

Endocytosis

Answer 39

Substances are engulfed into a cell by the formation of a vesicle around them

Question 40

Types of endocytosis ?

Answer 40

Phagocytosis Pinocytosis Receptor-mediated endocytosis

Question 41

Phagocytosis

Answer 41

Large particles are engulfed by pseudopodia formed by extensions of the cell membrane

Question 42

Pinocytosis

Answer 42

Liquids and small particles are captured in vesicles formed by unfolding of the cell membrane

Question 43

Receptor-mediated endocytosis

Answer 43

Vesicles are coated with receptors that recognize specific Ligands for endocytosis

Question 44

Macrophages

Answer 44

Pathogens are engulfed by the macrophage into a vesicle during endocytosis