Cellular respiration is the process by which living cells release energy. Aerobic respiration needs glucose and oxygen, while anaerobic respiration takes place without oxygen. There is no admission requirement attached to it: this is a Life Sciences topic, so the requirements below are what the national curriculum expects you to know.
The Department of Basic Education’s CAPS Life Sciences policy for Grades 10-12 places cellular respiration in Grade 11, Term 2, under Life Processes in Plants and Animals, with about 1½ weeks (6 hours) allocated.
Requirements at a Glance
- Glucose and oxygen are the raw materials of aerobic respiration
- Mitochondria and cytoplasm: aerobic respiration takes place in both, and mitochondria release energy during cell respiration
- No oxygen for anaerobic respiration, which in muscle produces lactic acid during exercise
- Industrial uses of anaerobic respiration, such as beer brewing and bread making
- A comparison of aerobic and anaerobic respiration in terms of raw materials, products and relative amounts of energy released
Raw Materials Required for Respiration
Aerobic respiration uses glucose and oxygen. CAPS expects you to describe it in words and symbols for glycolysis, the Krebs cycle and oxidative phosphorylation, without biochemical detail, and to say where it happens: in the cytoplasm and the mitochondria.
Respiration is not the same as breathing. CAPS asks you to distinguish between cellular respiration, breathing and gas exchange when you reach gaseous exchange in Grade 11, Term 3. Breathing and gas exchange move gases; respiration is the release of energy inside cells.
Aerobic and Anaerobic Requirements Compared
CAPS requires a comparison of aerobic and anaerobic respiration in terms of the raw materials required, the products and the relative amounts of energy released. Use this layout when you answer a comparison question.
- Aerobic: needs oxygen, takes place in the cytoplasm and mitochondria
- Anaerobic: takes place without oxygen
- Anaerobic in muscle: lactic acid is produced during exercise
- Industry: anaerobic respiration is used in beer brewing and bread making
For the amount of energy released, use the comparison in your prescribed textbook or your teacher’s notes, since CAPS does not give figures.
Products and Where the Energy Goes
Respiration is about energy for living cells, and CAPS lists the uses of that energy as part of the topic. In your answers, name the products of each type of respiration: carbon dioxide is produced by living organisms during respiration, and lactic acid is produced by anaerobic respiration in muscles. Mitochondria are the organelles that release energy during cell respiration, a point CAPS introduces in Grade 10 under cell structure.
How the Requirements Are Tested in Practicals
CAPS asks you to design an investigation or demonstration showing that oxygen is used and carbon dioxide is produced by living organisms during respiration. You must identify the variables, suggest controls for them and record your observations. CAPS suggests snails or seedlings as resources, but it does not prescribe particular apparatus, so use the method your teacher sets.
Assessment for Term 2 is made up of one formal recorded class test, a mid-year examination of 2½ hours and one practical task.
Frequently Asked Questions
What does respiration require?
Aerobic respiration needs glucose and oxygen and releases energy in the cytoplasm and mitochondria. Anaerobic respiration happens without oxygen.
Is respiration the same as breathing?
No. CAPS expects you to distinguish between cellular respiration, breathing and gas exchange.
What is the difference between aerobic and anaerobic respiration?
Aerobic respiration uses oxygen, while anaerobic respiration does not. Anaerobic respiration in muscle produces lactic acid, and it is used in beer brewing and bread making. CAPS asks for the comparison to cover raw materials, products and relative energy released.
Which grade is respiration taught in?
Grade 11, Term 2, in the Life Sciences CAPS, with 6 hours allocated.
Curriculum content and assessment requirements are set in the CAPS Life Sciences policy, so confirm the current requirements with your teacher and the Department of Basic Education at education.gov.za. See admission requirements and browse all education requirements.