diffusion (and microscopes?)

Question 1

Define diffusion

Answer 1

the net movement of particles from a region of their higher concentration to a region of their lower concentration down a CONCENTRATION GRADIENT, as a result of their random movement.

it is a passive process, and doesn’t require energy from the cell.

Question 2

List the factors affecting diffusion

Answer 2

ー Temperature
ー Distance
ー Concentration gradient
ー Surface area to volume ratio

TCDS (temperature, concentration gradient, distance, SA:volume)

Question 3

How does temperature affect the rate of diffusion?

Answer 3

With higher temperature, particles gain more kinetic energy, and the particles move FASTER.

Faster movement of particles = a faster rate of diffusion.

Question 4

How does distance affect the rate of diffusion?

Answer 4

It depends on the distance the particles have to travel.

Shorter distances, the rate will be faster due to the fact that less surface area has to be crossed/covered.

Question 5

How does the concentration gradient affect the rate of diffusion?

Answer 5

A big difference between concentrations of 2 areas = high concentration gradient. Then diffusion will occur faster to balance and reach equilibrium.

Question 6

How does the surface area to volume ratio affect the rate of diffusion?

Answer 6

Larger surface area, compared to the VOLUME of the organism/cell/bacteria allows for a quicker rate of diffusion.

i.e the rate of diffusion for an elephant would be very SLOW, since the volume of an elephant > than the surface area

This is why diffusion only mainly occurs in cells and bacteria, due to their SA to volume ratio.

Question 7

How to calculate magnification of drawing?

Answer 7

Magnification = how much an actual image has been enlarged by

Magnification(m) = Size of image (i) / Size of actual (a)