Plant Nutrition

Plant tissue

Carbs, proteins, lipids

Photosynthesis chemical equation

6CO2 + 6H20 —> C6H12O6 + 6O2

Why is sunlight needed in p/s?

Provides light energy that is then converted into chemical energy in bonds of glucose

Why is glucose produced in p/s?

Simple sugar used in respiration to release more energy.

Used to make cellulose cell walls.

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How is glucose stored in plants?

Starch- insoluble

Sucrose- soluble and transported around plant (phloem)

Fructose- in fruits

Chlorophyll

Molecule that captures light energy from the sun, found in palisade mesophyll

4 leaf adaptations

Long and broad- large surface area to absorb light

Green- contains chlorophyll that captures light

Network of veins- carry water and other substances

Thin- allows diffusion

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Layers of a leaf

Cuticle

Upper epidermis

Palisade mesophyll

Spongy mesophyll

Vein

Lower epidermis

Stomata and guard cells

Upper epidermis

Transparent layer for light to reach palisade cells

Thin waxy cuticle to reduce water evaporation and prevent disease

Palisade mesophyll

Main photosynthesis location

Tightly packed cells

Contains lots of chloroplasts

Spongy mesophyll

Loosely packed cells

Air spaces

Gas exchange

Stomata

Pores controlled by guard cells

Allow diffusion of gasses and water

Investigating the effect of light on gas exchange by a leaf

4 sealed boiling tubes containing large leaves and hydrogen carbonate indicator

1 tube in bright light, 1 in dark, 1 in muslin and 1 control

The more p/s, the more CO2, the darker (yellow-purple)

Testing leaf for starch

Remove leaf

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Leave heat in boiling water to denature enzymes

Add boiling tube of ethanol in double boiler

Add leaf to remove all chlorophyll

Wash leaf in cold water

Add iodine solution

If starch present, turns black

Test for CO2

Soda lime absorbed carbon dioxide inside a bell jar

Factors that affect photosynthesis

Light intensity

Carbon dioxide

Temperature

Limiting factor

The factor that slows down the rate of p/s

Nitrate use

Making amino acids, proteins and chlorophyll

Stunted growth

Phosphate uses

Making DNA

Poor root growth and young leaves turn purple

Potassium uses

Needed for enzymes and respiration

Leaves turn yellow with dead spots

Magnesium

Part of chlorophyll molecule

Leaves turn yellow