biogenetics

• What is photosynthesis?


  Photosynthesis is the process by which plants make glucose from sunlight.
• What type of reaction is photosynthesis?

  Photosynthesis is an endothermic reaction.
• How is energy transferred in photosynthesis?

  Energy is transferred from the environment to the chloroplasts by light.
• What is the equation for photosynthesis?

  Carbon dioxide + water → glucose + oxygen.
• What is the chemical symbol for carbon dioxide?

  CO​2
• What is the chemical symbol for water?

  H​2​O
• What is the chemical symbol for oxygen?

  O​2
• What is the chemical formula for glucose?


  C​6​H​12​O​6
• What factors affect the rate of photosynthesis?

  Temperature, light intensity, carbon dioxide concentration, and amount of chlorophyll.
• How does temperature affect the rate of photosynthesis?

  With an increase in temperature, the rate of photosynthesis increases until enzymes begin to denature.
• What happens to enzymes at high temperatures during photosynthesis?

  Enzymes begin to denature, causing the rate of reaction to decrease.
• How does light intensity affect the rate of photosynthesis?

  The higher the light intensity, the faster the rate of the reaction for most plants.
• What is the role of carbon dioxide in photosynthesis?

  Carbon dioxide is needed to make glucose.
• How does the amount of chlorophyll affect photosynthesis?

  If chlorophyll levels are reduced, the rate of photosynthesis decreases.
• How can you measure the rate of photosynthesis in a plant?

  By measuring the oxygen production of a plant.
• What is the experimental setup to measure the rate of photosynthesis using pondweed?


  • Place pondweed in a test tube full of water, sealed with a bung.
  • Attach a capillary tube with water leading into the test tube.
  • Position a lamp at a measured distance from the test tube.
  • Measure the distance the oxygen bubble moves in the capillary tube.
  • Control variables like temperature, time, and light intensity.

  
• What is a limiting factor in photosynthesis?


  A limiting factor is an environmental condition that restricts any increase in the rate of photosynthesis.
• How can a graph indicate a limiting factor in photosynthesis?

  A graph shows one limiting factor if it has one line that levels off, with the factor on the horizontal axis and rate of photosynthesis on the vertical axis.
• What does a graph with two lines represent in terms of limiting factors?

  A graph with two lines represents two limiting factors in two experiments conducted under different environmental conditions.
• How is light intensity measured in experiments related to photosynthesis?

  Light intensity is measured in lux.
• What is the inverse square law in relation to light intensity?

  Light intensity is inversely proportional to the square of the distance from the light source.
• If a lamp is 2 meters away from a plant, what is the light intensity compared to its original value?

  The light intensity is a quarter of its original value.
• What are the uses of glucose produced from photosynthesis?

  1. For respiration
  2. Converted into insoluble starch for storage
  3. To produce fat or oil for storage
  4. To produce cellulose for strengthening cell walls
  5. Combined with nitrates to form amino acids for protein production

  
• What is respiration?


  Respiration is the process of transferring energy from glucose so living processes can occur.
• What type of reaction is respiration?


  Respiration is an exothermic reaction.
• What are the two types of respiration?

  Aerobic respiration and anaerobic respiration.
• What happens to respiration during exercise?

  Respiration occurs faster, requiring more oxygen to be supplied to cells.
• How does the body respond to increased energy needs during exercise?

  By increasing heart rate, breathing rate, and breath volume.
• What is aerobic respiration?

  Aerobic respiration uses oxygen and yields the most energy.
• What is the equation for aerobic respiration?


  C​6​H​12​O​6​ + O​2​ → CO​2​ + H​2​O
• What is anaerobic respiration?

  Anaerobic respiration occurs when there is not enough oxygen and does not yield as much energy as aerobic respiration.
• When is anaerobic respiration used?

  Anaerobic respiration is used as a last resort, for example during a sprint when it is difficult to breathe in enough oxygen.
• What is produced during anaerobic respiration in animals?

  Lactic acid is produced during anaerobic respiration in animals.
• What is fermentation in plants and yeast cells?

  Fermentation is the process where glucose is converted into ethanol and carbon dioxide.
• What is oxygen debt?


  Oxygen debt is the amount of extra oxygen the body needs after exercise to react with accumulated lactic acid.
• What happens to lactic acid after exercise?

  Lactic acid is transported to the liver where it is converted back to glucose.
• What is metabolism?


  Metabolism is the sum of all the reactions in a cell or the body.
• What is the role of energy transferred in respiration?

  The energy transferred in respiration is used in metabolic processes to make new molecules.
• What are examples of metabolic reactions?

  1. Glucose converted to starch, glycogen, and cellulose.
  2. Glycerol and fatty acids forming a lipid molecule.
  3. Glucose and nitrate ions forming amino acids for protein production.
  4. Reactions in respiration.
  5. Urea formation from the breakdown of proteins for excretion.