Membranes and Transport

Question 1

facilitated diffusion

Answer 1

transport proteins help other molecules pass through cell membrane

Question 2

active transport

Answer 2

• ATP required
• transports molecules Against move their concentration
• not as common but still necessary.

Question 3

osmosis

Answer 3

net movement of water across plasma membrane due to concentrations gradients

Question 4

endocytosis

Answer 4

moves molecules to big membrane for proteins into the cell

Question 5

exocitosis

Answer 5

moves molecules to big membrane for proteins out of cell

Question 6

hypotonic

Answer 6

substance concentration is higher inside than outside, water will move into cell = causing cell to swell

Question 7

isotonic

Answer 7

substance concentration is same outside as inside; no change in shape to cell

Question 8

hypertonic

Answer 8

substance is more concentrated in outside than inside, water will move out of cell = causes cell to shrink

Question 9

diffusion

Answer 9

net movement of anything generally from a region of higher concentration to a region of lower concentration

Question 10

What are the components of the plasma membrane? What roles do they play? What is meant by the term ‘fluid-mosaic’?

Answer 10

plants = cell wall ; separating inside and outside of cell
animals = sugar molecules ; help create polysaccharides
- the plasma membrane is fluid like

Question 11

What types of molecules are able to cross the plasma membrane through simple diffusion? Give some examples.

Answer 11

individual water molecules, gases, polar but uncharged molecules

Question 12

How do a red blood cell and a plant cell react in an environment that is hypertonic relative to the inside of the cell?

Answer 12

Isotonic = no change in shape of cell
Hypotonic = cell swells
Hypertonic = cell shrinks
Osmosis = causes all^

Question 13

passive transport

Answer 13

• no ATP required by cell, simple and facilitated diffusion
• molecules will move down the concentration gradient