Homeostasis

• Why is maintaining a core temperature of 37°C important?

  It enables enzymes involved in metabolism to function efficiently
• What processes do enzymes control in living organisms?

  Metabolic processes
• What are the optimal conditions for enzyme activity?

  • Optimal temperature: Varies (e.g., 37°C for humans)
  • Optimal pH: Varies (e.g., 8 for trypsin)
• What is the optimal pH for enzymes?

  Specific pH range where enzymes function best
• How does pH affect the rate of enzyme-catalyzed reactions?

  Enzyme activity is optimal at a specific pH. Deviations from the optimum pH can lead to decreased activity due to changes in enzyme structure and conformation.
• What are the main components of the body temperature regulation system?

  • Stimulus: Body temperature exceeding 37°C
  • Sensor: Nerve cells with endings in skin and brain
  • Control Center: Temperature regulatory center in brain
  • Effector: Sweat glands throughout the body
• If body temperature rises, what immediate action do blood vessels take?

  They widen to increase heat loss
• What are enzymes classified as?

  Biological catalysts
• What are the effectors triggered by the hypothalamus when body temperature rises?

  • Blood vessels widen
  • Sweat glands produce sweat
  • Breathing rate increases
• What is homeostasis?


  The ability to maintain a stable internal environment
• What is the role of the liver in blood glucose homeostasis?

  • Stores glucose as glycogen when insulin levels are high.
  • Breaks down glycogen into glucose and releases it into the blood when glucagon levels are high.
• What role do enzymes play in relation to homeostasis?

  They control chemical reactions that require stable conditions
• What happens to enzymes at high temperatures?

  They can denature
• Why is glucose critical for cellular function?

  It provides immediate energy for cells
• What is the core temperature the body maintains?

  37°C
• What can extremes in pH do to enzymes?

  Disrupt enzyme structure and reduce function
• What are the effects of temperature and pH on enzyme activity?

  • High temperatures: Denature enzymes
  • Low temperatures: Slow enzyme activity
  • Extremes in pH: Disrupt structure and function
• What is the primary function of homeostatic mechanisms in the body?

  To maintain optimal enzyme conditions
• Why are stable internal conditions important for enzyme activity?

  They ensure optimal enzyme shape and function
• What shape is used to represent the relationship between enzyme activity and pH?

  Bell-shaped curve
• What occurs when all enzyme active sites are occupied?

  Reaction rate levels off and does not increase
• What does homeostasis ensure regarding enzymes?

  Enzymes operate at optimal efficiency
• At what temperature does the body's temperature regulation system activate in response to overheating?

  37°C
• Describe the relationship between temperature and the rate of enzyme-catalyzed reactions.

  • Increased temperature initially increases the rate due to increased molecular motion and collision frequency.
  • However, high temperatures can denature enzymes, leading to decreased activity.
  • There is an optimal temperature range for maximum enzyme activity.
• What are the three independent variables being studied in the images?

  1. pH
  2. Temperature
  3. Substrate concentration
• What hormone does the pancreas produce when glucose levels fall?

  Glucagon
• Explain how substrate concentration influences the rate of enzyme-catalyzed reactions.

  • Low substrate concentration: rate increases linearly with substrate concentration as more enzymes become occupied.
  • Medium substrate concentration: rate increases gradually as more substrate competes for available enzymes.
  • High substrate concentration: rate plateaus as all enzyme active sites become saturated.
• At what pH does amylase work best?

  7.0-7.1
• How does insulin and glucagon work together to maintain blood glucose levels?

  Insulin lowers blood glucose by facilitating uptake into cells and glycogen storage in the liver, while glucagon raises blood glucose by promoting glycogen breakdown in the liver. They act as opposing hormones to maintain glucose homeostasis.
• What are the specific optimal conditions for enzyme function?

  • Optimal pH range
  • Specific temperature range (0-40°C)
  • Appropriate substrate concentration
• What happens in the body when blood glucose levels fall?

  • Alpha cells in the pancreas release glucagon into the blood.
  • Glucagon stimulates the liver to break down glycogen into glucose.
  • Glucose is released into the blood, raising blood glucose levels back towards the set point.
• What can affect the shape and function of enzymes?

  Changes in temperature or pH
• Which organs act as effectors in the body's temperature regulation system?

  Sweat glands throughout the body.
• What are the normal glucose levels maintained in the body?

  $90mg / 100ml$
• Which part of the brain acts as the control center for temperature regulation?

  Hypothalamus
• What does glucagon stimulate in the liver?

  Breakdown of glycogen into glucose
• What is the role of amylase?

  Breaks down carbohydrates
• How does the optimal pH affect enzyme activity?

  Enzymes function best within a specific pH range
• What physiological response occurs when sweat glands are activated?


  They produce sweat to cool the body
• What is the target body temperature that these mechanisms aim to maintain?

  37°C