Paper 1

• What is the purpose of the cell membrane in a plant cell?

  It determines which substances enter and exit the cell.
• What is the function of the cell wall in a plant cell?

  It provides structural support.
• What is the role of the vacuole in a plant cell?

  It is important for structure.
• Where do most reactions take place in a plant cell?

  In the cytoplasm.
• What are ribosomes responsible for in a cell?

  Protein synthesis.
• What is the function of chloroplasts in a plant cell?

  They are involved in photosynthesis.
• What is the role of mitochondria in a cell?

  They release energy.
• What is the function of the nucleus in a cell?


  It is the control center that holds DNA.
• What are the main differences between plant and animal cells?

  Plant cells have a cell wall, vacuole, and chloroplasts, while animal cells do not.
• What is a bacterial cell's chromosome like?


  It contains DNA not enclosed in a nucleus.
• What is the function of flagella in a bacterial cell?


  It is used for locomotion.
• What is cell differentiation?


  It is the process where cells become specialized for specific functions.
• What are the specialized cells in the human body and their functions?


  • Villi: Increase surface area for absorption.
  • Neurons: Transmit electrical signals over long distances.
  • Muscle cells: Stretch and contract for movement.
• How do enzymes work?


  They have specific active sites that bind to substrates to form enzyme-substrate complexes.
• What happens to enzymes at low temperatures?


  They have insufficient energy to function effectively.
• What is the optimal temperature for enzyme activity?


  It is the temperature at which enzyme activity is at its peak.
• What does denaturation of an enzyme mean?


  It means the enzyme's structure is altered, affecting its function.
• How does pH affect enzyme activity?


  Extreme pH levels can denature enzymes, affecting their active sites.
• What is the relationship between substrate concentration and enzyme activity?


  Enzyme activity increases with substrate concentration until all active sites are filled.
• What does lipase do?


  It breaks down fats into fatty acids and glycerol.
• What are the main topics covered in Edexcel GCSE Biology Paper 1?


  Cells and control, genetics, natural selection, genetic modification, health, disease, and medicines
• What is the difference between eukaryotic and prokaryotic cells?


  Eukaryotic cells have a nucleus, while prokaryotic cells do not
• Where is lipase produced?


  In the pancreas and small intestine.
• What is the function of the cell membrane?


  It keeps everything inside the cell and is semi-permeable
• What does protease do?


  It breaks down proteins into amino acids.
• What is the role of mitochondria in a cell?

  Mitochondria are where respiration takes place, releasing energy for the cell
• Where is protease produced?


  In the stomach, pancreas, and small intestine.
• What is the function of ribosomes?


  Ribosomes are where proteins are assembled or synthesized
• What does amylase do?


  It breaks down starch into sugars.
• What is the function of chloroplasts in plant cells?


  Chloroplasts contain chlorophyll and are where photosynthesis takes place
• What is the role of enzymes in biological processes?


  Enzymes are biological catalysts that speed up chemical reactions
• Where is amylase produced?


  In the salivary glands, pancreas, and small intestine.
• How does amylase function in the body?

  Amylase breaks down starch into glucose and is found in saliva and the small intestine
• What is diffusion?


  It is the movement of substances from high to low concentration.
• What is the lock and key principle in enzyme activity?


  It describes how a substrate must fit the enzyme's active site to form a complex
• What happens to an enzyme when the temperature exceeds its optimum level?


  The enzyme denatures, changing shape and preventing substrate binding
• How does diffusion occur in the lungs?


  Oxygen diffuses from the lungs into the blood, and carbon dioxide diffuses from the blood into the lungs.
• What is the effect of pH on enzyme activity?


  Extreme pH levels can denature enzymes, affecting their activity
• What is osmosis?


  It is the movement of water through a partially permeable membrane from high to low water concentration.
• What is the procedure for testing the effect of temperature on amylase activity?


  1. Mix amylase with starch at different temperatures.
  2. Start timing and remove drops every 10 seconds.
  3. Use iodine to test for starch presence.
  4. Record the time taken for starch to be broken down.
  5. Plot times against temperature to find optimum temperature.