Photosynthesis

• Photosynthesis is 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.
• During photosynthesis, plants produce glucose, a simple sugar used by cells for respiration.
• The food that plants produce is important, not only for the plants themselves, but for the other organisms that feed on the plants.
• Photosynthesis requires energy in the form of light to drive the chemical reaction.
• Photosynthesis is an endothermic reaction in which energy is taken in.
• The light energy required for photosynthesis is absorbed by a green pigment called chlorophyll.
• Chlorophyll, the green chemical inside the chloroplasts of plant cells, enables photosynthesis to take place in the leaves.
• Chlorophyll is located in chloroplasts, which contain the green pigment chlorophyll and are the site of photosynthesis.
• Oxygen is formed as the waste product of photosynthesis and is used for the plant's respiration, and also released which makes it available for respiration to animals and many microorganisms.
• Stomata are tiny holes in the epidermis (skin) of a leaf that control gas exchange by opening and closing and are involved in loss of water from leaves.
• Plant cells are the basic unit of life and are found in unicellular organisms and multicellular organisms.
• Some of the glucose produced by photosynthesis is used for respiration.
• The glucose not used for respiration is used in the following ways: photosynthesis, respiration, and biosynthesis.
• Spongy mesophyll tissue is the plant tissue in a leaf which has loosely packed cells and air spaces between them to allow gas exchange.
• Unicellular organisms have only one cell, while multicellular organisms have many cells, particularly in the palisade and spongy mesophyll tissues of a leaf.
• Glucose is the starting point for the biosynthesis of materials that plants need to live.
• During the day, provided the rate of photosynthesis is sufficiently high, plant leaves, and water plants, give out oxygen.
• Palisade mesophyll tissue is plant tissue containing closely packed cells in the upper layer of a leaf.
• Water enters the plant through the roots, and is transported to the leaves in the xylem vessels.