Cell biology: Transport in cells

Question 1

Define diffusion

Answer 1

The net movement of particles from an area of high concentration to an area of low concentration down the concentration gradient

Question 2

Define osmosis

Answer 2

The net movement of water from an area of high concentration to an area of low concentration down the concentration gradient

across a semi permeable membrane

Question 3

Define active transport

Answer 3

The net movement of particles from an area of low concentration to an area of high concentration against the concentration gradient

using ATP energy

Question 4

Is diffusion active or passive

Answer 4

Passive

Question 5

Is active transport active or passive

Answer 5

active

Question 6

What factors can affect diffusion

Answer 6

• the difference in concentrations (concentration gradient) : the steeper the gradient the faster diffusion
• the temperature: the higher the temp, the more energy particles,
• the surface area of the membrane: the more surface area the more particles that can move in

Question 7

Can starch move into a cell via diffusion

Answer 7

No because it is too big

Question 8

Can oxygen move into a cell via diffusion

Answer 8

Yes because it is small enough

Question 9

why can single cell organsim use diffusion to transport molecules from their surroundoings into their body

Answer 9

they have a large surface to volume ratio

Question 10

can multicellurar organism rely on diffusuon

Answer 10

no, becuase their surface area to volume ratio is too big

Question 11

How do mutlticelluar organisms transport molecyles in an out of cells

Answer 11

they have adapations

Question 12

what adapations do multicelluar organisms have

Answer 12

The effectiveness of an exchange surface is increased by:

• having a large surface area
• a membrane that is thin, to provide a short diffusion path
• (in animals) having an efficient blood supply
• (in animals, for gaseous exchange) being ventilated.