Movement

Question 1

What is facilitated diffusion ??

Answer 1

molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers

In the cell, examples of molecules that must use facilitated diffusion to move in and out of the cell membrane are glucose, sodium ions, and potassium ions

Question 2

Simple diffusion

Answer 2

Diffusion is movement of molecules moving from a high to low concentration down a concentration’s gradient

Question 3

Factors that affect rate of diffusion

Answer 3

Higher difference in concentration gradient
Higher tempature
Larger surface area
Smaller molecule
Shorter distance for diffusion

Question 4

Smaller molecule or ion

Answer 4

Less kinetic energy is needed to move a smaller molecule/ion so at the tempature a smaller molecule will have move faster, therefore increasing rate of diffusion

Question 5

Shorter distance

Answer 5

If speed is the same but distance is smaller then time taken to travel that distance must be smaller

Question 6

Higher tempature

Answer 6

Molecules have more kinetic energy so move faster there are likely to be more collision’s, increasing rate

Question 7

Large surface area

Answer 7

The more space there is for diffusion to occur the faster it can happen as there are more opportunities for diffusion to happen

Question 8

Concentration gradient

Answer 8

The bigger the difference the concentration , the greater the probability of molecules / ions colouring over the region , therefore increasing rate.

Question 9

Net movement of particles form a concentrated solution to a dilute solution down a concentration gradient

Answer 9

Passive - don’t require engere
Take places in liquid and gas so can move freely
Continues until equilibrium is reached
Different concentration of one substance (only)