Theme B: Form and function
How structure matches function at every scale: carbohydrates, lipids and proteins; membranes and organelles; specialised cells; gas exchange, transport and movement in organisms; and the adaptations and niches of species in their environment.
Molecules
B1.1 Carbohydrates and lipids
Why can small changes in the shape of a sugar or lipid molecule give it a completely different job?
B1.2 Proteins
How can just twenty building blocks produce proteins with almost any shape or job?
Cells
B2.1 Membranes and membrane transport
How do lipids and proteins self-assemble into a working membrane?
B2.2 Organelles and compartmentalization
Why does dividing a cell into separate compartments make it more efficient?
B2.3 Cell specialization
How does one fertilised egg give rise to hundreds of very different cell types?
Organisms
B3.1 Gas exchange
Why do bigger organisms need special organs for gas exchange?
B3.2 Transport
How do animals and plants move fluids around large bodies using pressure?
B3.3 Muscle and motility
What happens inside a muscle at the molecular level when it shortens?
Ecosystems
B4.1 Adaptation to environment
How do the physical conditions of a place shape the organisms that can live there?
B4.2 Ecological niches
What are the many different ways organisms get the energy and matter they need?