BIOLOGY: Organisation

• What are the levels of organisation in multicellular organisms?

  Cells, tissues, organs, organ systems

  
• How do unicellular organisms differ from multicellular organisms?

  Unicellular organisms consist of one cell
• What is the role of specialised cells in multicellular organisms?

  They perform specific functions
• What does the respiratory system do?

  Provides oxygen and removes carbon dioxide
• What is digestion?

  A process that breaks down food molecules
• What is the alimentary canal?

  The passage through which food flows
• What is the role of accessory organs in digestion?

  They produce substances needed for digestion
• What are the two types of organs in the digestive system?

  Alimentary canal and accessory organs
• What is the role of bacteria in the large intestine?

  They aid in digestion and nutrient supply
• What is the microbiota?

  A microbial ecosystem in the gut
• How do bacteria help in digestion?

  By breaking down indigestible substances
• What can disrupt the gut microbiota?

  Taking antibiotics
• What is metabolism?

  The sum of all reactions in a cell
• What are enzymes made from?

  Proteins
• How do enzymes speed up reactions?

  By acting as biological catalysts
• What happens to substrates when they bind to enzymes?

  A chemical reaction occurs, forming products

  
• What determines the specificity of an enzyme?

  The shape of the active site

  
• What happens to enzymes at high temperatures?

  They can become denatured

  
• How does temperature affect enzyme activity?

  Higher temperatures increase reaction rates

  
• What is the purpose of chemical digestion?

  To break down large molecules into smaller ones
• What is the role of amylase?

  To break down starch into maltose

  
• Where is amylase produced?

  Salivary glands, pancreas, small intestine
• What do proteases do?

  Break down proteins into amino acids

  
• Where does protein digestion occur?

  In the stomach and small intestine
• What are the two main roles of bile?

  Neutralise stomach acid and emulsify fats
• What is the role of the pancreas in digestion?

  Produces digestive enzymes and hormones
• How is glucose used after digestion?

  In respiration to release energy
• What can the products of lipid digestion be used for?

  To build new cell membranes and hormones
• What are the main functions of the digestive system?

  • Digestion of food
  • Absorption of nutrients
  • Providing energy to cells
  • Supplying materials for growth and repair

  
• What is the process of digestion in the human body?

  1. Ingestion of food
  2. Mechanical digestion (chewing)
  3. Chemical digestion (enzymes break down food)
  4. Absorption of nutrients into the bloodstream
  5. Elimination of waste
• What are the effects of temperature and pH on enzyme activity?

  • Enzymes have an optimum temperature (around 37°C)
  • High temperatures can denature enzymes
  • Most enzymes have an optimum pH of 7
  • Extreme pH levels can denature enzymes

  
• What are the products of digestion used for in the body?

  • Building new carbohydrates, lipids, and proteins
  • Providing energy through glucose
  • Supporting growth and repair of cells
• What is the primary function of the lungs?

  Gas exchange
• How does breathing affect gas exchange in the lungs?

  It maintains high oxygen and low carbon dioxide levels
• What is the total surface area of each lung?

  About 70 m²
• What are the two halves of the heart responsible for?

  The right side pumps to lungs; left pumps to body
• Why is a double circulatory system beneficial?

  It allows for faster oxygen delivery to cells
• What happens to blood pressure in the lungs?

  It decreases to allow gas diffusion
• What is the role of the right side of the heart?

  Pumps deoxygenated blood to the lungs
• What is the role of the left side of the heart?

  Pumps oxygenated blood to the body