Compare carbohydrate and lipid structures, then connect condensation, hydrolysis, solubility and molecular organisation to energy storage, membranes and recognition.
Carbon is an essential element for life on Earth and must be distributed and recycled within ecosystems.
Outline the chemical properties of carbon that allow it to form diverse compounds.
The diagram shows some of the metabolic processes taking place in a plant cell.
State the type of reaction which converts excess monosaccharides to polysaccharides.
Explain why digestion of large food molecules is essential.
Insect pollinators are vital to maintaining the biodiversity of ecosystems, but they are threatened by some human actions. Some pollinators, such as honey bees (Apis mellifera), produce honey, which is rich in glucose.
Outline how the properties of glucose are linked to their uses in organisms.
Describe the structure and function of starch in plants.
Label the area where cellulose is found in the micrograph of a plant cell.
Cellulose is the most abundant organic polymer on Earth. Describe the structure of cellulose.
Outline one reason for humans being unable to digest cellulose.
Animal cells often secrete glycoproteins as extracellular components. What is a role of these glycoproteins?
Adhesion
Additional energy reserve
Membrane fluidity
Water uptake
Fats are used by mammals and oils are used by plants for energy storage. Both of these types of lipid are triglycerides.
Explain the reasons for oils being insoluble and sugars such as glucose being soluble in water.
The diagram shows the structure of a triglyceride.
Identify the type of reaction used to form the covalent bond indicated by X .
Identify the molecule that was used to form part Y of the triglyceride.
The diagram shows the structure of a triglyceride.
State the type of fatty acid shown as Z .
The diagram shows the structure of a triglyceride.
Explain how the properties of triglycerides make them suitable for energy storage.
Cells in the alveolus wall produce a surfactant. Its function is to prevent alveoli collapse at the end of expiration. Surfactants are used in the treatment of respiratory system disease in premature babies.
The table shows some of the components of different surfactant preparations.
Phospholipids found in the surfactants form a surface film on the moist lining of the alveoli. Outline how the hydrophilic and hydrophobic parts of the phospholipids in the surfactants are aligned on the alveolar surface.