Cell transport 1B

Question 1

what is a sub-cellular structure?

Answer 1

small structures inside the cell e.g nucleus

Question 2

what does differentiation mean?

Answer 2

when a cell becomes a specialised cell.

Question 3

What is mitosis?

Answer 3

cell division where one set of chromosomes are pulled to each end of the cell and the nucleus divide

Question 4

How to work out magnification

Answer 4

= size of image / size of real object

Question 5

What is diffusion?

Answer 5

diffusion is the spreading out of particles ( in a solution or gas ) resulting in net movement from an area of higher concentration to an area of lower concentration

Question 6

What is the concentration gradient?

Answer 6

the difference in concentration between 2 areas

Question 7

Which way do particles move in diffusion

Answer 7

particles move down the concentration gradient

Question 8

what does it mean when the concentration gradient is steeper?

Answer 8

the steeper it is the more likely particles are going to diffuse down the concentration gradient, so diffusion is faster.

Question 9

What happens to diffusion at a higher temperature?

Answer 9

all particles have more kinetic energy
more likely to spread out from a high to low concentration
diffusion is faster

Question 10

What happens to diffusion with surface area?

Answer 10

the larger the surface area of the membrane the quicker particles will diffuse at once
diffusion is faster

Question 11

what does distance have to do with diffusion?

Answer 11

if particles have further to diffuse the longer it’ll take
diffusion will be slower

Question 12

How to work out the surface area

Answer 12

mm squared x number of sides

Question 13

how to work out the volume

Answer 13

mm side length cubed ( x3 )

Question 14

How to work out surface area : volume ratio

Answer 14

SA / Volume

Question 15

how to work out the rate of diffusion?

Answer 15

min-1

Question 16

How are the alveoli adapted for efficient gas exchange

Answer 16

large surface area
- many aveoli
- spherical shape
maintain concentration gradient
- breathing and ventilation
- good blood supply
Short distance
- one flattened cell thick

Question 17

How are villi adapted?

Answer 17

Short Distance
- one cell thick
many villi
- large surface area
Maintain concentration gradient
- peristalsis ( muscle contraction )
- rich bloody supply

Question 18

How are Fish gills adapted?

Answer 18

thin - short diffusion distance
many gill filaments - large SA
Rich bloody supply - maintain concentration gradient

Question 19

How are leaves in plants adapted?

Answer 19

Large SA - large flat leaves
Thin leaves - short diffusion distance
spongy cells with air space - large SA - diffusion in gas is faster

Question 20

how are roots in plants adapted?

Answer 20

thin cell walls - short diffusion distance
root hairs - large surface area
many mitochondria - active transport of mineral ions - maintains concentration gradient for water uptake

Question 21

Osmosis definition

Answer 21

diffusion of water from a dilute solution to a concentrated solution across a partially permeable membrane

Question 22

how to work out a percentage change

Answer 22

% change = final mass - start mass
start mass x100

Question 23

What is active transport?

Answer 23

substances move from an area of low concentration to an area of higher concentration against a concentration gradient
Requires energy from respiration

Question 24

Key facts about active transport

Answer 24

1. low -> high concentration
   against the gradient
2. needs energy - respiration
3. Many mitochondria needed
4. aerobic respiration needs
   oxygen
5. carrier proteins are needed

Question 25

Functions active transport in the villi

Answer 25

function - absorbs food - glucose
many mitochondria - energy for respiration
carrier proteins transports glucose