B8: Photosynthesis Flashcards Preview

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Flashcards in B8: Photosynthesis Deck (13)
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1

Photosynthesis...

 - equation

 - what is it

Where plants make food using carbon dioxide, water and light. It is an endothermic reaction (energy taken from enviroment, temp goes up).

2

The process of Photosynthesis?

  • Uses energy to change Carbon Dioxide and Water into Glucose and Oxygen.
  • Takes place in chloroplasts 
  • Energy is transferred to the chloroplasts from the environment by light

3

Producing Oxygen

4

Leaf Adaptations

  • Broad leaves (bigger surface area for light to fall on)
  • leaves are thin (diffusion distance for gases are short)
  • Contain chlorophyll in chloroplasts (absorb light)
  • Have veins (bring plenty of water in xylem to cells of leaves, remove products of photosynthesis in the phloem)
  • Have air spaces (allow COto get to the cells and oxygen leave by diffusion)
  • Have guard cells that open and close the stomata (regulate gas exchange)

5

Uses of Photosynthesis?

 - other ways that plants use the glucose they produce during photsynthesis?

 - Plants use some of the glucose they produce to make a substance which strengthen their cell walls. What is it?

  • Respiration
  • Making cellulose
  • Making amnio acids
  • Stored as oils or fats
  • Stored as starch

Cellulose is answer to question because it supports the cell and strengthens it.

6

Required Practical...

Investigate the effect of light intensity on the rate of photosynthesis using pondweed.

Youtube: https://www.youtube.com/watch?v=hITp-60mqzg

              : Effect of a Varying Light Intensity on Rate of Photosynthesis-Updated

 

See A4 Booklet

7

How do you measure Light Intensity?

8

Limiting factors

 - what is meant by a limiting factor by the rate of photosynthesis?

Limit the rate of reaction, stops photsynthesis from happening any faster, e.g. photosynthesis

9

What factors affect the rate of Photosynthesis?

  • Light
  • Temperature - too hot, enzymes needed for photsynthesis and its other reactions will be damaged making them denatured causing a rapid decrease in photosynthesis
  • Carbon Dioxide concentration

10

Rate of Photosynthesis graphs...

  • Light
  • Temperature
  • Carbon Dioxide Concentration

Light:

  • More light, the more photosynthesis that takes place (only to a certain point)
    • Because as the light intensity increases, the rate will no longer increase because either the temperature or CO2 level is now the limiting factor not light
  • Provides energy needed for photosynthesis

Temperature:

  • Affects the enzymes involved
  • If this is the limiting factor, because the temp is too low
    • enzymes work a lot slower
  • too hot, enzymes can get damaged
  • Enzymes get destroyed at roughly 45oc

Carbon Dioxide:

  • Raw material needed for photsynthesis
  • More CO there is, will increase the rate of photosynthesis up to a cetain point.
  • At flat line, Light or temperature needs to be increased
  • Curve, plenty of light and warmth

11

How do plants use glucose?

  • During photosynthesis during respiration
  • broken down using oxygen to provide energy for the cells
  • Carbon dioxide and water are waste product

Lipids:

  • Plants and algae use some of the glucose from photosynthesis and energy tansferred to build up fats and oils
    • used in the cells as energy store
    • used in cell walls to make them stronger
    • energy store in their seeds
      • provide food for the new plant to respore as germinates 

Nitrates, Proteins and Carnivorous plants:

  • Plants use some of the glucose from photosynthesis to make amio acids
    • combining sugars with nitrate ions and other mineral ions from the soi
    • build up to proteins
    • be used in plant cells (enzymes)
  • Algae also make amnio acids
    • take nitrate ions from water they live in
  • Some carnivorous plants i.e. Venus Flytraps, are adapted to live in nitrate-poor soil.
    • Nutrients from animals i.e. insects
    • Plants produce enzymes to digest the insects they trap

Cellulose for strength, startch for storage:

  • Energy transferred in respiration may be used to build up smaller molecules into bigger ones
  • Plants convery some of the glucose they produce in photosynthesis into starch to be stored
    • Glucose is insoluble in water
    • Lots of glucose stored in the plant cells could affect the water balance if the whole plant
  • Starch is insoluble in water
    • no effect on the watter balance of plant making plant be able to store large amounts of starch in cells
    • Starch is stored in the cells of the leaves
    • Starch is kept in special storage areas of a plant

12

higher...

Ideal conditions for photosynthesis

Greenhouse...

  • trap suns heat
  • Temperature doesn't become limiting 
  • Artifical light after sun goes down to maintain photosynthesis
  • Can use it all year round
    • not depent on the weather
  • Increase level of Carbon dioxide
  • Keeping them enclosed limits the pests and diseases
  • it is very expensive but if done correctly, then it could save them money

13

What does C6H12O6 represent?

Glucose