Plants and PHotosythesis

A flower’s job is to make seeds. The parts of a flower are all attached to a swollen base, known as the receptacle. The outer green parts of the flower are called sepals. The sepals protect the flower bud before it opens. Inside the flower are the reproductive organs.

There are some long stems called anthers. The anthers make tiny grains of pollen. There is also a stigma, at the bottom of the stigma, nestling at the heart of the flower are the ovules. Each of these ovules contains a tiny egg; which grows into a seed when fertilised by a pollen grain.

A seed contains a baby plant with its own supply of food, all wrapped in a tough outer coat. All the seed needs to grow is water and warmth. To begin with, the plant feeds on the store of food that was in the seed. When the leaves reach the light the plant uses its leaves to make its own food from sunlight, air and water.

All living things, plants and animals are made up of tiny “boxes” called cells. Most Cells can only be seen with a microscope. They multiply and grow, pushing the stem tip upwards and the root tip down into the ground. Some plant cells can be several centimetres long, though they are still very narrow. Long cells like these make up tubes that carry food and water through a plant. Most plants grow at the tips of their stems and roots. They get longer because new microscopic cells are added there.

The stem keeps the plant upright and holds the leaves so they can get sunlight. Inside the stem are tiny tubes which carry water from the roots and food from the leaves.

Roots hold the plant in the ground. They also take in water and minerals from the soil.

Root hair cells grow from behind the tip of the root and the extensions give the cells a larger surface area to absorb water and minerals from the soil.

The leaves Make Food for the plant by PHOTOSYNTHESIS, for this to happen, Sunlight is absorbed by green chlorophyll. This is why leaves are green.

Palisade Cells are fund in the leaves and stems of plants. They absorb light from the sun and use it to make food during Photosynthesis.

word equation for photosynthesis :

Light energy

water + carbon dioxide >>>>>>>>>>>>>>>>>>>> glucose + oxygen

Chlorophyll

The leaves provide a very large surface area for plants to photosynthesise. Leaves fan out so that they dont shade each other. Leaves are long, thin and full of chloroplasts which contain the green pigment chlorophyll.

Chlorophyll cam absorb light energy and convert it into chemical energy which can be used by the plant.

The shape of the cells in the palisade layer ensures that nearly all of the light falling on the leaf is absorbed by the chloroplasrs in these cells.

Sodium bicarbonate indicator changes colour at different ph's.

Plants use carbon dioxide in photosynthesis and therefore remove it from the solution

This makes the indicator more alkaline.

Therefore plants closests to the light carried out more photosynthesus than those further away.

Some of it will be used straight away for respiration. This isa process which releases energy. It happens in plant cells all of the time

Some glucose is changed into cellulose to make new cell walls this helps plant cells to hold their shape and helps the plant to support itself.

Some is added to minerals from the soil. it can then be used with nitrogen to make proteins or magnesium to make chlorophyll. These minerals come from the soil and are taken up by the roots

Photosynthesis is the process in which a plant uses up carbon dioxide.

during the day when the sun is out. This is when plants photosynthesise.

The brightet the light the more the plant can perform photosynthesis, and it can do this faster.

It is known that photosynthesis gets faster if there is more light. It is also known that photosynthesis gets faster if there is more carbon dioxide. an experiment was set up to see if this was also true for plants under water. An pondweedwas but in a bottle of water near a bulb. It started to give of gas bubbles these contained oxygen. The light bulb was moved further away so the amount of gas bubbles containing oxygen will decrease this because there is less light to perform photosythesis. Extra carbon dioxide was disolved into the water this is because when plants respire they produce Carbon Dioxide. They need to respire to release energy.