IGCSE Biology glossary
Carrier protein
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Definition
A membrane protein that binds to specific molecules or ions and transports them across the cell membrane. Carrier proteins are involved in active transport, using energy from respiration to move substances against the concentration gradient.
What to include in an exam answer
In active transport answers, mentioning carrier proteins and energy from respiration earns higher marks. The carrier protein changes shape to move the substance across.
Example in context
Describe the role of carrier proteins in active transport (2 marks): Carrier proteins bind to specific ions or molecules and use energy from respiration to change shape, transporting the substance across the membrane against the concentration gradient.
Related syllabus topic
Movement into & out of cells