Plants Nutrition

Content Photosynthesis Energy for the reaction Raw materials Products of the reaction Word equation Chemical equation Structure of leave Stomata The rate of photosynthesis Carbon dioxide Light Temperature Limiting Factors Carbon dioxide-limiting Factors Light-limiting Factors Temperature-limiting Factors Minerals Dificiency Nitrogen Phosphorus Potassium Magnesium Fertilisers (NPK) Greenhouse production Reference Questions

How do plants get the food they need?All living organisms need food to grow and survive.

Plants are known as producers because they provide food for many other organisms.

Plants cannot move very much, so how do they get the food that they need?

Green plants are the only living organisms that are able to do this.

All other organisms rely on plants because of the food that the plants make.

What is the name of the process by which plants make their own food?

Nutrition in green plants

Plants make their own food by photosynthesis.This process is a chemical reaction that uses light energy.

What is photosynthesis?

light energy

The word photosynthesis comes from the Greek language:

“photo” means “light”“synthesis” means “putting together”

Photosynthesis just means “putting together with light”.What do green plants “put together” to make their food?

Photosynthesis is a chemical reaction between carbon dioxide and water.

Energy is needed for this reaction to take place.

Where do plants get this energy from?

Photosynthesis: energy for the reaction

carbondioxide

water

light energy

The raw materials for photosynthesis come from the air and the soil.

What are these raw materials called?

What else do plants need to turn carbon dioxide and water into food?

Photosynthesis: raw materials

carbondioxide

water

Plants use light energy from the Sun to power photosynthesis.

Where in the leaf does this reaction take place?

Photosynthesis takes place in what part of plant cells?

Photosynthesis: where it happens

carbondioxide

water

light energy

Photosynthesis takes place in plant cells with chloroplasts.

Chloroplasts contain the green chemical called chlorophyll.

Chlorophyll absorbs the energy from sunlight that allows carbon dioxide and water to react.

What are the products of this reaction?

Photosynthesis: where it happens

carbondioxide

water

light energy

chlorophyll

The products of the reaction between carbon dioxide and water are glucose and oxygen.

Which of these products is used by plants?

What happens to the ‘waste’ product?

Photosynthesis: products of the reaction

carbondioxide

water

glucose

oxygen

light energy

chlorophyll

Glucose is the useful product for plants.

Some glucose is used straightaway by plant cells, some is converted to starch for storage and later used for food.

Oxygen is the ‘waste’ product. This gas is transported out of the leaf into the air.

Why is this important for humans and other living things?

Photosynthesis: products of the reaction

carbondioxide

water

light energy

chlorophyll

oxygen

glucose

Photosynthesis: summary

Summarize the process of photosynthesis in one sentence.

Photosynthesis is a chemical reaction that takes place in the chloroplasts

in green plant cells, where light energy is used to convert carbon dioxide and water

into glucose and oxygen.

Photosynthesis: word equation

carbondioxide

water

oxygen

light energy

chlorophyll

glucose

glucose

light energy

chlorophyll

carbondioxide water oxygen

Photosynthesis: chemical formulae?

Photosynthesis is a chemical reaction involving molecules.

glucose

light energy

chlorophyll

carbondioxide water oxygen

CO2 H2O O2C6H12O6

Structure of a leaf

How are leaves designed to maximize photosynthesis?

Leaves are wide and flatto create a large surface

area and to absorb as much light as possible.

Leaves are thin so gases can reach cells easily.

Leaves have holes, called stomata, on their

underside through which gases move in and out.

Leaves have lots of veins to carry water to the cells and carry glucose away.

Leave Inner Structure

Stomata

Stomata is a pore, found in the epidermis of leaves, stems and other organs that is used to control gas exchange.

The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the opening.

Open in the morning. Close at night.

Photosynthesis is a chemical reaction and so has a rate.

Is the rate of photosynthesis always the same?

The rate of photosynthesis

light

glucose

light energy

chlorophyll

carbondioxide water oxygen

The rate of photosynthesis varies depending on three main factors:

How do these factors affect the rate of photosynthesis?

carbon dioxide temperature

Light and the rate of photosynthesis

Light energy has to be absorbed by chlorophyll for photosynthesis to take place.

glucose

light energy

chlorophyll

carbondioxide water oxygen

The brighter the light, the more light energy there is, so will photosynthesis be faster or slower?

More light energy means that photosynthesis will be faster.

If light intensity is too high plant cells can be damaged.How is photosynthesis affected if this happens?

Carbon dioxide is one of the raw materials used by plants to make their food.

Carbon dioxide and the rate of photosynthesis

glucose

light energy

chlorophyll

carbondioxide water oxygen

The concentration of carbon dioxide in the air (0.03%) is actually quite low.

Why is the concentration of carbon dioxide in commercial greenhouses often raised to about 0.1%?

More carbon dioxide means more photosynthesis, so plants make more food and grow quicker.

Photosynthesis is controlled by enzymes.Enzymes usually work best at warmer temperatures.

Temperature and the rate of photosynthesis

glucose

light energy

chlorophyll

carbondioxide water oxygen

Why is the rate of photosynthesis slower on a sunny day in winter compared to in summer?

If the temperature gets too hot (above 40 °C), plant enzymes begin to break down and are destroyed or denatured.

Why does photosynthesis stop under such conditions?

What is a limiting factor?

A factor present in an environment that controls a process, particularly the growth, abundance or distribution of a population of organisms in an ecosystem.

Photosynthesis and light – limiting factors

How does the amount of light affect the rate of photosynthesis on this labelled graph?

As the amount of light increases, so does the rate. The limiting factor is light.

light intensity

rate

of

pho

tosy

nth

esis

Here, increasing the amount of light has no affect on the rate. The limiting factor is now carbon dioxide or temperature.

What must be increased for the rate to increase?

1

2

1

2

Photosynthesis and carbon dioxide – limiting factors

How does the amount of carbon dioxide affect the rate of photosynthesis on this labelled graph?

As the amount of carbon dioxide goes up, so does the rate. The limiting factor is carbon dioxide.

concentration of carbon dioxide

rate

of

pho

tosy

nthe

sis

Here, increasing the amount of carbon dioxide has no affect on the rate. Light or warmth is now the limiting factor.

What must be increased for the rate to increase?

1

2

1

2

Photosynthesis and temperature – limiting factors

How does temperature affect the rate of photosynthesis on this labelled graph?

1. As temperature increases, so does the rate because photosynthetic enzymes work best in the warmth. Here, the limiting factor is temperature.

temperature

rate

of

phot

osy

nthe

sis

0oC 45oC

Most plant enzymes are destroyed at about 45°C. Here, photosynthesis stops and the rate falls to zero.What is the limiting factor?

1

2

1

2

What minerals do plants need?

Plants need mineral elements for healthy growth.

Some of the most important minerals needed by plants are:

The mineral elements are found in salts dissolved in water.Plants obtain minerals when they absorb water from the soil.

How do plants obtain these minerals?

nitrogen

potassium ions

phosphorus

potassium

magnesium magnesium ions

phosphates

nitrates

What type of salt are each of these elements found in?

What are minerals needed for?

How do plants use these mineral elements?

Mineral element

How mineral is used in plants

nitrogen (N)

phosphorus (P)

potassium (K)

magnesium (Mg)

making leaves

making roots

making flowers and fruit

making chlorophyll

Where do minerals come from?

Rocks: The minerals in rocks are slowly dissolved by slightly acidic rainwater. These minerals are washed into the soil.

Natural fertilizers: Animal faeces and the decay of dead plants and animals return minerals to the soil.

Artificial fertilizers: These contain a ready-made mixture of the minerals needed by plants.

What are the sources of minerals in the soil?

Why do farmers add fertilizers to their soil?

Not enough minerals!

What happens if plants do not get enough minerals?

Plants do not grow properly if they are deprived of minerals and begin to look unhealthy.

If a plant does not get enough of a mineral it is said to have a mineral deficiency.

Mineral deficiency – no nitrogen!

Nitrogen is used for making leaves and is probably the most important mineral for plant growth.

What is the effect of nitrogen deficiency?

lower leaves yellow and dead

weak stem

upper leaves pale green

Mineral deficiency – no phosphorus!

Phosphorus is used for making roots and is important for all the other minerals used by plants.

What is the effect of phosphorus deficiency?

small roots

purple leaves

Mineral deficiency – no potassium!

Potassium is used for making flowers and fruit, so crops are given extra potassium before they start to fruit.

What is the effect of potassium deficiency?

poor flower and fruit growth

yellow leaves with dead spots

Mineral deficiency – no magnesium!

Magnesium is used for making chlorophyll and so is vital for the process of photosynthesis.

What is the effect of magnesium deficiency?

upper leaves normal (leaves turn yellow from bottom upwards)

lower leaves pale green or yellow

Fertilisers (NPK)

• Fertilisers make crops grow faster and bigger so that crop yields are increased. They're minerals, which must first dissolve in water so that plants can absorb them through their roots.

• Fertilisers provide plants with the essential chemical elements needed for growth particularly nitrogen, phosphorus and potassium. The proportions of these elements in a fertiliser are often shown as N:P:K = 15:30:15.

Greenhouse production Farmers can use their knowledge of factors limiting the rate of

photosynthesis to increase crop yields. This is particularly true in greenhouses, where the conditions are more

easily controlled than in the open air outside: The use of artificial light allows photosynthesis to continue beyond

daylight hours. Bright lights also provide a higher-than-normal light intensity.

The use of artificial heating allows photosynthesis to continue at an increased rate.

The use of additional carbon dioxide released into the atmosphere inside the greenhouse also allows photosynthesis to continue at an increased rate.

Reference

• www.google.com• https://www.google.co.th/search?

q=fertilisers+npk&espv=2&biw=1366&bih=623&source=lnms&tbm=isch&sa=X&ei=ZPFAVZ-wOY6juQShn4H4Dg&ved=0CAcQ_AUoAQ#tbm=isch&q=fertilisers+

• http://feeco.com/npk-fertilizer-what-is-it-and-how-does-it-work/

• http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/chemical/fertilisersrev1.shtml

• http://en.wikipedia.org/wiki/Fertilizer• www.bbcbitesize.com• Biology for Cambridge IGCSE (Book)• Others Books for Biology IGCSE

Plant and minerals (Question)

Mineral Use in plant Deficiency signs

nitrogen

phosphorus

potassium

magnesium

Complete this table of plant mineral needs and deficiencies.

making leaves

making roots

making flowersand fruits

making chlorophyll

stunted growth and yellow leaves

poor roots and purple leaves

yellow leaves with dead spots

leaves turn yellow from the bottom

Questions

1. Write down the balanced chemical equation for photostnthesis. On the equation identify the sources of energy, raw material, and by-product.

2. Write down the word equation for photosynthesis3. Define: Limiting factor Stomata Fertilisers NPK

Label the parts of inner structure of leave.

Thanks for your attention Hope u all understand :)

Done By: Faiq & Rizan