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Flashcards in Transport across a cell membrane 2 Deck (17)
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1

What is the cell membrane made of

Phospholipids and proteins

2

How can the membrane be described as and why

Fluid because the phospholipids are constantly moving

3

4 examples of what the function of a protein on a cell membrane

-Form channels which can allow molecules that are small enough to travel through
-Receptors
-Enzymes
-Carrier proteins for active transport

4

What word describes the cell membranes function

Selectively permeable, this means that some molecules can pass from one side to another while others cant

5

What is passive transport and does it need energy

Passive transport does not require energy instead it relies on the fact substances are found in different concentrations in different places . Substances always move from a higher to lower region of concentration; down a concentration gradient

6

What is diffusion

Diffusion is the movement of molecules or ions from a region of high concentration to low concentration

7

When does diffusion stop

When the concentration of the substance is even throughout

8

What does diffusion allow

Diffusion allows substances to move within a cell as well as allowing material to enter and leave

9

What is osmosis

Osmosis is the movement of water molecules from a region of high to low water concentration through a selectively permeable membrane

10

What molecules move by osmosis

Water

11

What is active transport

Active transport is the movement of molecules against a concentration gradient

12

How do the molecules move in active transport

Molecules are moved by carrier proteins which requires energy provided by ATP

13

What happens when a plant or animal cell is placed in solution of equal concentration in the cell and surrounding solution

The cell will remained unchanged

14

What happens when the surrounding solution of the plant cell has a greater water concentration than in the vacuole

The cell will become swollen. This is defined as turgid

15

What happens if the solution surrounding of the plant cell has a lower water concentration than in the cell

The water will leave the cell. This is defined as plasmolysed

16

What happens when the surrounding solution of the animal cell is greater than in the cell

The cell will burst as there is no cell wall

17

What happens if the surrounding solution has a loer water concentration than in the cell

Water will pass out the cell causing it to shrivel and shrink