Capter 5 - Movement Through Cell Membranes

Question 1

Diffusion

Answer 1

Movement of molecules from a region of high concentration to a region of low concentration

Question 2

Examples of diffusion in everyday life

Answer 2

1) Smell of perfume
2) Tea bag in boiling water
3) Stink bomb

Question 3

Osmosis

Answer 3

The movement of water across a semi-permeable membrane from an region of high water concentration to an area of low water concentration

Question 4

Osmosis is diffusion but…

Answer 4

Diffusion is not osmosis

Question 5

Dilute solutions have

Answer 5

• a high concentration of water molecules

- a low concentration of solute

Question 6

Concentrated solutions have

Answer 6

• a low concentration of water molecules

- a high concentration of solute

Question 7

Plant roots use osmosis to

Answer 7

Absorb water

Question 8

Plasmolysis

Answer 8

• This is when water leaves a plant cell, it’s cell membrane recedes from the cell wall
• the cell is plasmolysed

Question 9

Turgor

Answer 9

• When water enters the plant cell the cytoplasm swells pushing the cell membrane against the cell wall
• when cells are fully “swelled” they are turgid

Question 10

Turgor pressure

Answer 10

• Gives plants their strength

- without turgor they’d wilt

Question 11

Animal cells respond differently to plant cells to the gain and loss of water because…

Answer 11

…plants have a cell wall which is fully permeable

Question 12

Extra Cellular Fluid

Answer 12

Fluid in our bodies that surround our cells

Question 13

Function of the kidneys….

Answer 13

-To make sure our extra cellular fluid maintains a stable concentration

Question 14

Stable extra cellular fluid concentration of important because

Answer 14

-Plasma must have the same concentration as our blood cells will easily burst of overfilled

Question 15

What happens if an animal cell is put in a solution more concentrated than their cytoplasm?

Answer 15

The water in their cytoplasm will go from an area of high concentration to low concentration and the cell will shrivel and die

Question 16

What happens if a cell is put into a solution that is less concentrated than its cytoplasm?

Answer 16

The water in the outside solution will go from an are of high concentration to low concentration, overfill the cell and burst it

Question 17

Two most common causes of food spoilage

Answer 17

Bacteria

Fungi

Question 18

How is osmosis used in food preservation

Answer 18

• Bacteria and fungi cells are killed by dehydration as the water is pulled from their cells into the very sugary or very salty solution that the food is kept in

Question 19

Fish and meat may be stored in

Answer 19

• a salty solution

Question 20

Jams, marmalades, and tinned fruits may be stored in

Answer 20

• a sugary solution

Question 21

Substances move in and out of cells in 2 ways

Answer 21

1) Passive transport

2) Active transport

Question 22

Passive transport

Answer 22

• when a cel does not use energy to move particles across a membrane
• particles move down their concentration gradient
• e.g. Diffusion and osmosis

Question 23

Active transport

Answer 23

• when a cell uses energy to move particles across a membrane active transport occurs
• particles go up their concentration gradient