photosynthesis Flashcards
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algae
definition
A group of organisms that photosynthesise but lack the complex range of cell types and organs found in land plants. Most algae are aquatic. All have chloroplasts.
biomass
definition
The dry mass of an organism.
carbon dioxide
definition
A gaseous compound of carbon and oxygen, which is a by-product of respiration, and which is needed by plants for photosynthesis.
cell
definition
Basic unit of life. Unicellular organisms only have one cell. Multicellular organisms have many cells.
chlorophyll
definition
The green chemical inside the chloroplasts of plant cells. It enables photosynthesis to take place.
chloroplast
definition
Contains the green pigment chlorophyll; the site of photosynthesis.
denature
definition
If a substance is denatured, its structure and function is altered. This can be caused by heat, altered pH or by chemical agents.
enzymes.
endothermic
definition
Reaction in which energy is taken in from the surroundings.
enzyme
definition
A protein which catalyses or speeds up a chemical reaction.
glucose
definition
A simple sugar used by cells for respiration.
light
definition
Visible electromagnetic radiation.
limiting factor
definition
A factor which, if in short supply limits or reduces the rate of photosynthesis, eg temperature, light intensity and carbon dioxide concentration.
organ
definition
A group of different tissues that work together to carry out a particular function, eg heart and lungs.
photosynthesis
definition
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.
respiration
definition
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.
stomata
definition
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.
xylem vessels
definition
Narrow, hollow, dead tubes with lignin, responsible for the transport of water and minerals in plants.
Photosynthesis
overview
Green plants and algae use light energy to make glucose and oxygen from carbon dioxide and water. Temperature, carbon dioxide concentration and light intensity can affect the rate of photosynthesis.
Photosynthesis
Algae
Algae can also make their own food by the process of photosynthesis. Plant biomass will increase as a result of photosynthesis.
Photosynthesis equation
Carbon dioxide + water →(light)→ Glucose + oxygen