An intracellular enzyme is an enzyme that functions within the cell it was produced.Enzymes are needed to synthesise polysaccharides, proteins and a variety of molecules within cells.Catalase is an enzyme found in both plant and animal tissue that catalyses the breakdown of hydrogen peroxide to oxygen and water.Hydrogen peroxide is a by-product of some metabolic reactions and will damage cells if allowed to accumulate.Enzymes are biological catalysts that catalyse specific reactions due to their specific 3D structure.Catalase is a quaternary protein containing four haem groups.The Fe3+ ions in the haem prosthetic group allow the enzyme to interact with hydrogen peroxide.Enzyme catalysing the steps of respiration will be in almost all cells except red blood cells which have no mitochondria.Some enzymes such as amylase may be both intracellular and extracellular.
Intracellular Enzymes
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Specification: OCR Biology A (H020), AS-level, 2.1.4 Enzymes. Topic: Enzymes.
Key terms in this lesson
- mitochondrion
- An organelle with a double membrane, the inner one folded into cristae, that is the site of aerobic respiration and ATP production.
- prosthetic group
- A non-protein group that is permanently and tightly bound to a protein and is needed for it to function, such as the haem group in haemoglobin.