Unit 2 Metabolism & Survival
Key Area 1: Metabolic Pathways
Metabolic Pathways are integrated and controlled pathways of enzyme-catalysed
reactions within a cell.
Metabolic Pathways can have reversible steps, irreversible steps and alternative routes.
Catabolic and Anabolic Reactions
Reactions within metabolic pathways can be anabolic or catabolic.
Anabolic Reactions
Anabolic reactions build up large molecules from small molecules and require energy.
, Catabolic Reactions
Catabolic reactions break down large molecules into smaller molecules and release
energy.
Protein pores, pumps and enzymes are embedded in membranes.
Membranes consist of proteins and phospholipids. The phospholipids create a bilayer and
are constantly moving. This gives the membrane flexibility.
Channel-forming proteins create pores which control the diffusion of small molecules
across the cell. Diffusion= movement of molecules from an area of high concentration to
an area of low concentration.
Key Area 1: Metabolic Pathways
Metabolic Pathways are integrated and controlled pathways of enzyme-catalysed
reactions within a cell.
Metabolic Pathways can have reversible steps, irreversible steps and alternative routes.
Catabolic and Anabolic Reactions
Reactions within metabolic pathways can be anabolic or catabolic.
Anabolic Reactions
Anabolic reactions build up large molecules from small molecules and require energy.
, Catabolic Reactions
Catabolic reactions break down large molecules into smaller molecules and release
energy.
Protein pores, pumps and enzymes are embedded in membranes.
Membranes consist of proteins and phospholipids. The phospholipids create a bilayer and
are constantly moving. This gives the membrane flexibility.
Channel-forming proteins create pores which control the diffusion of small molecules
across the cell. Diffusion= movement of molecules from an area of high concentration to
an area of low concentration.
