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Flashcards in Photosynthesis Deck (20)
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1
Q

Photosynthesis definition

A

Photosynthesis is the process by which plants make their own food

2
Q

Photosynthesis Equation

A

Chlorophyll
Carbon dioxide + water —————-> oxygen + glucose
Light

3
Q

Experiment to test leaves for starch

A
  1. Destarch leaf by placing in a dark room for 48hours
    Ensures that any starch detected is under conditions
  2. Boil the leaf in water
    This kills the leaf by stopping all chemical reactions
  3. Boil the leaf in ethanol
    Removes the green pigment so any colour change can be seen
  4. Dip leaf in water
    This softens leaf after ethanol makes it brittle
  5. Add iodine
    Detects starch. Yellow/brown-blue/black
4
Q

Other experiment test on leaves

A

Test for chlorophyll (variegated leaf)
Test for light (partially covered leaf)
Test for carbon dioxide (leave kept in air, treated with soda lime)

5
Q

Experiment to prove oxygen production in plants

A

A water plant, elodea, can be used to probe the production of oxygen. The gas collected will delight a glowing splint

6
Q

Affects of light intensity, temperature and carbon dioxide with photosynthesis

A

As light intensity increases so does the rate of photosynthesis as the pant absorbs the light. As it decreases so does the rate at which the bubbles are produced

At high temperatures the rate of photosynthesis will decrease

The higher the concentration of carbon dioxide the rate of photosynthesis increases
To stop warm temperatures from killing the plant, it is placed in a cool beaker of water

7
Q

How the products of photosynthesis are used

A
  1. Growth
  2. Storage
  3. Respiration
8
Q

Balance between photosynthesis and respiration

A

It can be demonstrated by using bicarbonate indicator as it detects changes in the concentration of carbon dioxide.

Normal (0.04)- red/orange
Increased- yellow
Decreased- purple

9
Q

Compensation point

A

This is when the processes of photosynthesis and respiration balance. The carbon dioxide and water is used in photosynthesis.

Remember plants respire all the time and only photosynthesise when there is light.

10
Q

Chemical equation for photosynthesis

A

6CO2 + 6H2O ——> CH12O6 + 6O2

11
Q

Factors affecting the rate of photosynthesis

A

Carbon dioxide
> rate will decrease if carbon dioxide is in short supply as it is a reactant in the process

Light
> rate will increase if light intensity increased. Light energy drives the process

Temperature
> rate will decrease if temperature are low as the molecules are moving slower and less likely to collide.

12
Q

Palisade mesophyll

A

Tall thin cells packed with chloroplasts

Ideal for trapping Light

13
Q

Stomata

A

Tiny pores in the leaf that allows gases to enter and leave the leaf.
More on the lower surface than the upper
Carbon dioxide diffuses through stoma

14
Q

Guard cells

A

Sausage shaped cells that surround the stoma
Controls the size of the stomata in order to reduce water loss
Contain chlorophyll

15
Q

Waxy cuticle

A

Waxy transparent layer that reduces evaporation but allows light through
Coats both sides of the leaf

16
Q

Upper epidermis

A

A layer of thin cells that act as a protective layer

17
Q

Spongy mesophyll

A

Loosely packed cells with large air spaces between

Site of gas exchange (air spaces make diffusion of gases more efficient )

18
Q

Vein

A

Carries water and mineral up the roots where they are absorbed

19
Q

Benefits from the structure of a leaf

A

Flat surface
Creates more surface area for light to be absorbed

Thin
Light can get to the chloroplasts in short distance for carbon dioxide to diffuse

Low density
It can hold position which maximum light can be absorbed

20
Q

Uses of glucose in a plant

A
Can be converted into:
cellulose for cell wall
Amino acids for growth
Starch for storage
Lipids for energy