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Flashcards in Transport Across Membranes Deck (20):
0

Movement of molecules from a high to low concentration down a concentration gradient

Diffusion

1

What is meant by the term flaccid?

When a cell becomes soft and can no longer support the plant due to water loss

2

What does the term turgid mean?

the cytoplasm is pushed against the cell wall, making it stretched to the maximum and the vacuole is swollen

3

What is meant by the term plasmolysed?

When the vacuole shrinks and the cytoplasm is pulled away from cell wall as a result of excessive water loss

4

What type of solution makes a cell turgid?

A dilute solution

5

What type of solution makes a cell plasmolysed?

A concentrated solution

6

What is a selectively permeable membrane?

It controls the entry and exit of certain materials into and out of a cell

7

What is osmosis?

It is the diffusion of water molecules from a high to a low concentration through a selectively permeable membrane

8

What is the difference in concentration that exists between two regions, resulting in diffusion?

Concentration gradient

9

Movement of molecules from low to high concentration, requiring energy

Active transport

10

What is a solution called with a higher water concentration than another solution?

Hypotonic

11

What is a solution called with a lower water concentration than another solution?

Hypertonic

12

What is two solutions with the same water concentration called?

Isotonic

13

What does the membrane have to let substances pass through?

Pores

14

What are diffusion and osmosis also know as?

Passive processes

15

What are carrier proteins?

They pick up specific molecules and move them through the cell membrane against the concentration gradient

16

What do cells need to provide energy to carry out active transport?

Mitochondria

17

What are the types of molecules that the cell membrane is made of?

lipid (fat) and protein

18

What is the double layer that the lipid molecules form?

Lipid bilayer (makes the membrane strong but flexible)

19

Why is the cell membrane called a fluid mosaic?

Because of the random arrangement of the protein molecules and how the membrane is a flexible