Energy

1
Energy

• Group 4
• Biology

2
Aim of Project

• Our focus has been on energy in plants and
  animals.
• Looked at how plants use their energy stores and
  how light energy is trapped in the plant.
• Also looked at how energy is released from food
  when used by humans.

3
Germination and energy

• Energy is stored within the seed as starch.
• It is used as an energy source at the time of
  germination.
• For germination several factors are required.
• Water
• Oxygen
• Suitable temperature

• Aim
• Investigation to find out how temperature
  (heat energy) effects the rate of germination.

4
Seed germination
5
What we did

• Planted seeds in soil, watered and incubated for
  5 days at the following temperatures
• 4o C
• 17o C
• 22o C
• 30o C
• 40o C
• 50o C

6
What we measured

• If a radicle and plumule (young root and shoot)
  emerged we measured their length.
• Also noted whether seed had swelled with water.

7
Results

• We found that the optimum temperature for
  germination was 22 oC
• At 4oC there was no germination because the
  enzymes were working too slowly

8
At high temperatures

• At 30oC most of the seeds did not germinate.
• At 40oC and above the enzymes were denatured
  (broken down)

9
Conclusions

• The optimum temperature for the germination of
  seeds was 22oC.
• The reason for this is that this is the optimum
  temperature for the enzymes required for
  germination

10
Light colour and growth

• Aim
• Experiment to find out how light colour
  effect the growth of plants.
• Background
• Plants require light energy for photosynthesis
  in order to make food.

11
Action Spectrum

• Green plants absorb and use blue and red light
  better than green light.
• We grew plants under different coloured lights
  and measured the length of the stem.

12
Results

• We found that plants grown under colourless and
  red light appeared healthy and had the greatest
  shoot length.
• Blue was the second best and then green, which
  grew etiolated.

etiolated
13
Coloured light

14
Energy from food

• Energy is required for all metabolic activities
  (reactions in the body).
• Aim
• Experiment to investigate the amount of energy
  in two different types of crisps.
• We looked at normal and lite crisps.

15
Heat energy

• One way to measure the amount of energy is to
  burn it.
• We measure the change in temperature of water
  while burning each crisp.
• The amount of energy in each crisp was then
  calculated in Joules.

16
Calculating energy content

• Energy specific heat capacity x mass x change
  in temp
• J J/kgoC
  kg OC
• The specific heat capacity of water 4200J/kgoC

17
Conclusions

• We found that the normal crisps contained more
  energy than the low fat crisps.
• This is because fat is used as an energy source
  and contained a high amount of stored chemical
  energy.

18
Thanks for watching we had a wheely good time
in Bang er!