The process of photosynthesis
Plants, unlike animals, can make their own food. They do this using a process called A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic.. The food that plants produce is important, not only for the plants themselves, but for the other organisms that feed on the plants. Getting optimum rates of photosynthesis produces maximum plant yields.
Greg Foot explains the effect of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis
During photosynthesis, plants produce A simple sugar used by cells for respiration. from simple A compound that does not include carbon combined with hydrogen. molecules – A gaseous compound of carbon and oxygen, which is a by-product of respiration, and which is needed by plants for photosynthesis. and water – using light energy.
The word and symbol equations for photosynthesis are:
Photosynthesis requires energy in the form of light to drive the chemical reaction. Photosynthesis is an Reaction in which energy is taken in. reaction.
The light energy required is absorbed by a green A coloured chemical. called The green chemical inside the chloroplasts of plant cells. It enables photosynthesis to take place. in the leaves. Chlorophyll is located in Contains the green pigment chlorophyll; the site of photosynthesis. in Basic unit of life. Unicellular organisms only have one cell. Multicellular organisms have many cells., particularly the Plant tissue containing closely packed cells in the upper layer of a leaf. and spongy The plant tissue in a leaf which has loosely packed cells and air spaces between them to allow gas exchange.. Revise plant cells and their part in photosythesis here.
Plant leaves are the main photosynthetic A group of different tissues that work together to carry out a particular function, eg heart and lungs., but any part of the plant exposed to the light will develop chlorophyll and photosynthesise.
The carbon dioxide required for photosynthesis comes from the air. It enters leaves through the Tiny holes in the epidermis (skin) of a leaf. They control gas exchange by opening and closing and are involved in loss of water from leaves. Singular is stoma.. Water enters the plant through the roots, and is transported to the leaves in the Narrow, hollow, dead tubes with lignin, responsible for the transport of water and minerals in plants..
Oxygen is formed as the waste product. Some is used for the plant's The chemical change that takes place inside living cells, which uses glucose and oxygen to release the energy that organisms need to live. Carbon dioxide is a by-product of respiration., and also released, which makes it available for respiration to animals and many microorganisms. During the day, provided the rate of photosynthesis is sufficiently high, plant leaves and water plants give out oxygen.
Biosynthesis
Some of the glucose produced by photosynthesis is used for respiration.
Glucose is also the starting point for the The production of more complex molecules, from simpler ones, in living organisms. of materials that plants need to live.
The glucose not used for respiration is used in the following ways:
There are four major uses of glucose produced in photosynthesis:
- Many glucose molecules are joined together to form Unable to dissolve in a particular solvent. For example, sand is insoluble in water. starch. This is a storage product of glucose in plants.
- Many glucose molecules are joined together to form insoluble cellulose. This is used to build cell walls for new growth.
- Glucose is joined with nitrates absorbed from the soil to make The building blocks that make up a protein molecule.. These are joined together to make proteins during The production of proteins from amino acids, which happens in the ribosomes of the cell..
- Glucose is also converted to Fat or oils, composed of fatty acids and glycerol., which is often stored in seeds.