Transport

Diffusion

The random movement of particles from an area of high concentration to an area of low concentration

number of molecules

The difference between the concentration is the ________ on either side of the membrane.

How can the rate of diffusion be increased - give three ways

Increasing the temperature, increasing the concentration, increasing surface area

Root hair cells

________ are adapted to take in water and mineral ions by:

What state of matter can diffusion not occur in

Solid

Why does increasing temperature increase the rate of diffusion

It gives the particles more energy

How do you calculate are of a square

width \* height

How do you calculate volume

width \* height \* depth

The cell membrane lets small particles pass through because of this we say it’s

Partially permeable

SA

V ratio

6

1

3

1

1.5

1

1

1

0.75

1

0.6

1

Alveoli

Found in the lungs

Leaves and root hair cells

In plants

Villi

Found in the small intestine

Gills

Found on fish (take oxygen out of the water)

Hypotonic solution

water moves into the cell, cell membrane pushes up against the cell wall and it becomes turgid

Isotonic solution

water moves out of the cell, the vacuole stops pushing out against the cell membrane and cell wall , the cell becomes flaccid

Hypertonic solution

if water continues to move out, the cell membrane pulls away from the cell wall it is plasmolised

What is a passive process

Doesn’t require energy to happen

Why do large multicellular organisms needed specialised exchange surfaces

They have a low surface area to volume ratio so a specialised exchange surface makes the process more efficient

Where are the alveoli found

In the lungs

Where are the villi found

In the small intestine

What are some adaptations of the villi/alveoli (list 3)

Large surface area, good blood supply, thin walls

What is osmosis

The movement of water molecules across a partially permeable membrane from an area of high concentration to low concentration until there is an equilibrium

What is the independent variable

The thing you change

What is the dependant variable

The thing you measure

What is the control variable

The things you keep the same

What happens in a hypotonic solution

Water moves into the cell cell membrane pushes up against the cell wall and it becomes turgid

What happens in a isotonic solution

Water moves out of the cell and the vacuole stops pushing out against the cell membrane and cell wall so the cell becomes flaccid

What happens in a hypertonic solution

If water continues to move out the cell membrane pulls away from the cell wall and it is plasmolised

What is active transport

The movement of substances from and area of low concentration to an area of high concentration against the concentration gradient