Control of blood glucose levels

• What hormones control blood glucose concentration?

  Insulin and glucagon
• What does blood glucose concentration describe?

  The amount of sugar in the bloodstream
• Why do cells need a constant supply of glucose?

  For respiration to produce energy
• What happens if blood glucose concentration is too high?

  It can damage our tissues
• What occurs when a person eats a large meal with carbohydrates?

  Blood glucose concentration increases
• How does the pancreas respond to high blood glucose levels?

  It releases insulin into the bloodstream
• What is blood glucose concentration?

  The amount of sugar in the bloodstream
• Why do we need to maintain a fine balance in blood glucose concentration?

  Too high can damage tissues, too low can starve cells
• What happens when we eat a meal high in carbohydrates?

  Carbs are broken down into glucose, absorbed into bloodstream
• How does the body respond to a rise in blood glucose?

  Pancreas releases insulin, which causes cells to take up glucose
• What is the role of insulin?

  Causes cells to take up glucose from the bloodstream
• What is the role of glucagon?

  Causes the liver to break down glycogen into glucose
• How do insulin and glucagon work together in a negative feedback loop to regulate blood glucose?

  • Insulin is released when blood glucose is high, causing cells to take up glucose
  • This lowers blood glucose levels back to normal
  • Glucagon is released when blood glucose is low, causing the liver to release stored glucose
  • This raises blood glucose levels back to normal
  • This creates a negative feedback loop to maintain blood glucose homeostasis
• If a person skips breakfast and has been active, what would happen to their blood glucose levels?

  Blood glucose levels would drop, causing the pancreas to release glucagon
• How do the functions of insulin and glucagon differ?

  Insulin decreases blood glucose, glucagon increases blood glucose
• What is glycogen?

  A long-term storage form of glucose in the body
• Where is glycogen primarily stored in the body?

  In the liver and muscle cells
• What are the key steps in the negative feedback loop for blood glucose regulation?

  1. Blood glucose rises (e.g. after a meal)
  2. Pancreas detects high glucose and releases insulin
  3. Insulin causes cells to take up glucose, lowering blood glucose
  4. Blood glucose drops too low
  5. Pancreas detects low glucose and releases glucagon
  6. Glucagon causes liver to release stored glucose, raising blood glucose
  7. Blood glucose returns to normal range
• How does the body use glycogen to regulate blood glucose levels?

  • When blood glucose is high, excess glucose is converted to glycogen for storage
  • When blood glucose is low, glycogen is broken down into glucose and released into the bloodstream
  • This helps maintain blood glucose homeostasis
• What is the formula to calculate the area of a circle?

  $A =$$\pi r^2$
• What are the key differences between scanning electron microscopes (SEMs) and transmission electron microscopes (TEMs)?

  • SEMs produce 3D images, TEMs produce 2D images
  • SEMs image the surface of samples, TEMs image the interior of thin samples
  • SEMs use a focused beam of electrons to scan the sample, TEMs use a broad beam to illuminate the entire sample
  • SEMs are better for studying surface features, TEMs are better for studying internal structures
• What is the first derivative of $x^2$?


  $2x$
• What are the strengths and weaknesses of qualitative research methods?

  Strengths:

  • Provides in-depth, rich data
  • Flexible and adaptable to new information
  • Captures complex phenomena

  
  

  Weaknesses:

  • Time-consuming and labor-intensive
  • Potential for researcher bias
  • Limited generalizability
  • Difficulty in replicating results
• If you wanted to observe the surface of a cell in detail, which microscope would you use?

  Scanning electron microscope (SEM)
• How does the process of photosynthesis work in plants?

  1. Light absorbed by chlorophyll
  2. Light-dependent reactions produce ATP and NADPH
  3. Calvin cycle fixes CO2 and produces carbohydrates