Chapter 1.2 Transport across cell membranes Flashcards Preview

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Flashcards in Chapter 1.2 Transport across cell membranes Deck (20):
1

The cell membrane is composed of

lipid and protein

2

The cell membrane is

selectively permeable

3

The difference in concentration of a substance is a

concentration gradient

4

Passive transport of a substance does not

require additional energy

5

Passive transport is the movement of molecules

from a high concentration to a low concentration against a concentration gradient.

6

Diffusion and osmosis are examples of

passive transport processes

7

Diffusion is the movement of substances from a

high concentration gradient to a lower concentration down a concentration gradient.

8

Some substances that enter cells by diffusion are

oxygen, glucose and amino acids

9

Some substances that leave cells by diffusion are

carbon dioxide and urea

10

Diffusion is important to cells because it provides the cell with

raw materials and helps to remove waste products

11

Osmosis is the movement of water molecules from a region of

high water concentration to a region of lower water concentration through a selectively permeable membrane.

12

An animal cell placed in a solution with a water concentration higher than that inside the cell will

take up water by osmosis and could burst

13

An animal cell placed in a solution with a lower water concentration than that inside the cell will

lose water by osmosis and could shrink.

14

A plant cell placed in a solution with a lower water concentration than that inside the cell will

take up water by osmosis and become turgid

15

A plant cell placed in a solution with a lower water concentration than that inside the cell will

lose water by osmosis and become plasmolysed.

16

Plasmolysed is when a cell

has a vacuole that has shrunk due to water loss, causing the cell membrane to pull away from the cell wall.

17

Turgid is when a cell or tissue

has a vacuole so swollen due to water gain that it presses the cytoplasm and cell membrane against the cell wall.

18

Active transport is the movement of molecules from a region of

low concentration to a region of higher concentration against a concentration gradient.

19

Active transport requires

additional energy in the form of ATP, to allow membrane proteins to move molecules against the concentration gradient.

20

A lipid is

Fat or oil with molecules composed of fatty acids and glycerol