organisation

• What is the basic unit of life?

  Cell
• What is a tissue?

  A group of similar cells performing a function
• What is an organ?

  Group of tissues working together
• What is an organ system?

  A group of organs working together
• What is an organism?

  A living individual
• What is the purpose of the digestive system?

  Breaks down food into smaller molecules for absorption
• What is the role of the mouth in digestion?

  Mechanical digestion and enzymes in saliva
• What is the function of the oesophagus?

  Moves food to stomach via peristalsis
• What does the stomach produce?

  Hydrochloric acid and protease enzyme
• What is the function of the small intestine?

  Produces enzymes and absorbs nutrients
• How does the liver contribute to digestion?

  Produces bile to neutralise stomach acid
• What is the role of the gallbladder?

  Stores bile
• What does the pancreas produce?

  Digestive enzymes
• What is the function of the large intestine?

  Absorbs water from undigested food
• What does the rectum do?

  Stores waste (faeces)
• What are enzymes?

  Biological catalysts that speed up reactions
• What is the Lock and Key Model in relation to enzymes?

  Enzymes have a specific active site for a substrate
• What happens to enzymes if temperature or pH is too extreme?

  They are denatured
• What does amylase do?

  Converts starch to sugars
• What does protease do?

  Converts proteins to amino acids
• What does lipase do?

  Converts lipids to glycerol and fatty acids
• What factors affect enzyme activity?

  Temperature and pH
• What is the optimum temperature for enzyme activity in humans?

  Approximately 37°C
• What is the function of the heart?

  Pumps blood throughout the body
• What is a double circulatory system?

  Right side pumps deoxygenated blood to lungs
• What do the atria do?

  Receive blood
• What do the ventricles do?

  Pump blood out
• What is the function of valves in the heart?

  Prevent backflow of blood
• What are arteries?

  Thick walls, carry blood away from heart
• What are veins?

  Thin walls, valves to prevent backflow
• What are capillaries?

  One-cell thick for efficient diffusion
• What do red blood cells do?

  Carry oxygen
• What do white blood cells do?

  Fight infections
• What do platelets do?

  Help with clotting
• What does plasma do?

  Transports substances like glucose and CO₂
• What is health?

  State of physical and mental well-being
• What are communicable diseases?

  Caused by pathogens like bacteria and viruses
• What are non-communicable diseases?

  Not infectious diseases like cancer and heart disease
• What are risk factors for diseases?

  Lifestyle choices and genetic factors
• What is cancer?

  Uncontrolled cell division