Cell Memebrane Functions/osmosis/transports

Question 1

What is passive transport

Answer 1

A molecule passing through the cell membrane with no use of ATP energy

Question 2

What is diffusion

Answer 2

The simplest form of passive transport

Question 3

Which direction will molecules move: higher to lower
Or
Lower to higher

Answer 3

Higher to lower

Question 4

What factors determine how easy it will be for a molecule to move across the cell membrane

Answer 4

Size and type of the molecule

Question 5

What is osmosis

Answer 5

The process by which water diffuses across a membrane

Question 6

Will water move to or away from a high solute concentration?

Answer 6

Water will move to the area with a high solute concentration
(Because the area will have a lower concentration of water)

Question 7

Hypotonic solution

Answer 7

Lower concentration of solute molecules, so more water. Meaning water will want to move away from a hypotonic area.

Question 8

Hypertonic Solution

Answer 8

Higher concentration of solute molecules, less water.
Water will want to move to this area

Question 9

Isotonic solution

Answer 9

Equal concentration of solute molecules
Water will move, or diffuse, to both areas equally

Question 10

What two things help cells deal with osmosis

Answer 10

Contractile vacuole - collects excess water and pumps it out of the cell (in freshwater unicellular organisms)
Cell walls - solid enough to keep the cell from bursting (in plants)

Question 11

What happens if cells can’t deal with osmosis

Answer 11

Plasmolysis - the cell shrivels because of loss of turgor pressure
Cytolysis - the cell bursts

Question 12

What is the osmotic condition of a plant that plant cells require

Answer 12

Hypotonic

Question 13

In what osmotic condition will a plant lose turgor pressure

Answer 13

Hypertonic

Question 14

How is facilitated diffusion carried out

Answer 14

Uses channel proteins to move molecules through the cell membrane
(No energy input needed)

Question 15

What are ion channels

Answer 15

Small passageways across the cell membrane

Question 16

What will ion channel gates respond to by opening or closing

Answer 16

Stretching of the cell membrane
Electrical signals
Chemicals in the cytosol or external environment

Question 17

Why do ions need the ion channels

Answer 17

Ions aren’t soluble in lipids, so they can cross the membrane

Question 18

What is active transport

Answer 18

Moves molecules up the their concentration gradient, from lower to higher
(Required energy)

Question 19

What are the carrier proteins used in active transport called?

Answer 19

Pumps
(More specifically sodium-potassium pumps)

Question 20

How do the sodium-potassium pumps work?

Answer 20

They move three sodium ions out of the cell for every two potassium ions it moves into the cell
(ATP supplies the energy for this process)

Question 21

Generally, what are endocytosis and exocytosis used for?

Answer 21

To transport macromolecules, food particles and large quantities of small molecules through the cell membrane inside vesicles

Question 22

What are vesicles?

Answer 22

Small vacuoles

Question 23

What is Exocytosis

Answer 23

Vesicles made by the cell fuse with the cell membrane, releasing their contents outside the cell

Question 24

What is endocytosis

Answer 24

The cell membrane folds around something and forms a pouch, the pouch then pinches off and becomes a vesicle in the cytoplasm

Question 25

What are the two types of endocytosis

Answer 25

Phagocytosis-“cell eating”-vesicles contain large particles or cells.
Pinocytosis-“cell drinking”- the vesicles contains solutes or fluids

Question 26

How does the structure of the cell membrane allow it to preform its functions
(Very long flash card, my b)

Answer 26

Phospholipid bi-layer- makes it so uncharged molecules can slip through the cell membrane.
Extremely hydrophobic inside - helps separate the cell from everything else
Carbs - hang on outside the cell and identify different molecules
Proteins - embedded in the membrane help ions pass through the membrane