, Topic 01: Photosynthesis and respiration
Glossary
Term Definition
Chloroplasts Organelle in the cell where photosynthesis takes place.
Chromatography Technique for analyzing components of a mixture.
Photosynthesis
What is photosynthesis?
• Essential to life on Earth.
• Energy source for all ecosystems.
• Plants use sunlight to produce food (glucose).
• Sunlight + carbon dioxide + water → glucose + oxygen.
The role of the sun
• The Sun is the main source of light and heat energy.
• Chlorophyll in leaves absorbs light energy.
• Photosynthesis uses this energy to make food.
The process of photosynthesis
• Occurs in green leaves (chloroplasts).
• Requires: light energy, water, carbon dioxide, chlorophyll.
• Glucose is formed, oxygen is a by-product.
• Leaves have openings for gas exchange and take up water via roots.
Plants as energy converters
• Chlorophyll captures solar energy and converts it into chemical energy.
• Glucose → starch (food storage) or cellulose (structure).
• Cellulose builds cell walls.
• Oxygen is released during the process.
Respiration (cell respiration)
The process of respiration
• Food contains energy in the form of glucose.
• Respiration breaks down glucose with oxygen to release energy.
Copyright © The Teacher's Pet Natural Sciences Grade 8 (Via Afrika) Page 2 of 26
, Energy is used for:
• Growth and cell division.
• Nerve impulses.
• Muscle contraction.
• Temperature management.
How does respiration work?
• Plants do photosynthesis and respiration.
• Animals get energy from food they eat.
• Energy is released in the mitochondria of cells.
• By-products: carbon dioxide and water.
• Oxygen is inhaled, glucose from food → energy + CO₂ + H₂O.
Copyright © The Teacher's Pet Natural Sciences Grade 8 (Via Afrika) Page 3 of 26
Glossary
Term Definition
Chloroplasts Organelle in the cell where photosynthesis takes place.
Chromatography Technique for analyzing components of a mixture.
Photosynthesis
What is photosynthesis?
• Essential to life on Earth.
• Energy source for all ecosystems.
• Plants use sunlight to produce food (glucose).
• Sunlight + carbon dioxide + water → glucose + oxygen.
The role of the sun
• The Sun is the main source of light and heat energy.
• Chlorophyll in leaves absorbs light energy.
• Photosynthesis uses this energy to make food.
The process of photosynthesis
• Occurs in green leaves (chloroplasts).
• Requires: light energy, water, carbon dioxide, chlorophyll.
• Glucose is formed, oxygen is a by-product.
• Leaves have openings for gas exchange and take up water via roots.
Plants as energy converters
• Chlorophyll captures solar energy and converts it into chemical energy.
• Glucose → starch (food storage) or cellulose (structure).
• Cellulose builds cell walls.
• Oxygen is released during the process.
Respiration (cell respiration)
The process of respiration
• Food contains energy in the form of glucose.
• Respiration breaks down glucose with oxygen to release energy.
Copyright © The Teacher's Pet Natural Sciences Grade 8 (Via Afrika) Page 2 of 26
, Energy is used for:
• Growth and cell division.
• Nerve impulses.
• Muscle contraction.
• Temperature management.
How does respiration work?
• Plants do photosynthesis and respiration.
• Animals get energy from food they eat.
• Energy is released in the mitochondria of cells.
• By-products: carbon dioxide and water.
• Oxygen is inhaled, glucose from food → energy + CO₂ + H₂O.
Copyright © The Teacher's Pet Natural Sciences Grade 8 (Via Afrika) Page 3 of 26
