The Stomach (AQA GCSE Biology): Revision Note

The stomach

• The stomach is an organ that forms part of the digestive system; its roles include:

  • production of protease enzymes to digest proteins into amino acid

  • production of stomach acid to provide an acidic environment for enzyme activity, and to kill pathogens in food

Levels of organisation

• The stomach illustrates the different levels of organisation:

  • Cells

  • Tissues

  • Organs

  • Organ systems

Cells

• The stomach contains cells that are specialised to secrete substances such as protease enzymes, stomach acid or mucus

Tissues

• Glandular tissue contains cells that secrete substances, for example enzymes or stomach acid

• Muscle tissue contains cells that can contract, allowing the stomach to churn food

• Epithelial tissue lines the stomach

Organs

• The stomach is an example of an organ; it is a group of tissues that work together to carry out part of the process of digestion

Organ systems

• The stomach works together with a series of other organs in the digestive system to digest food

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