2.4) Metabolism in Conformers and Regulators

Question 1

• State the abiotic factors that affect an organism’s ability to maintain its metabolic rate.

Answer 1

• Temperature 🌡️
• pH 🧪
• Salinity 🧂

Question 2

• What are the key points about conformers?

Answer 2

• Conformers’ internal environment is dependent upon the external environment 🌳
• Behavioural responses by conformers allow them to tolerate variations in their external environments
  ➞ (e.g. basking in the sun = absorbing heat energy directly + burrow under the surface = heating or cooling down)
• Conformers also tend to have:
  ➞ low metabolic costs ✨
  ➞ narrow ecological niche 🌱

Question 3

• What are the key points about regulators?

Answer 3

• Regulators maintain thier internal environment regardless of the external environment 🍃
• Regulators use metabolism to control thier internal environment by homeostasis
  ➞ (e.g. maintains a balance in: body temperature, water levels and glucose levels)
• Regulators tend to have:
  ➞ high metabolic costs⚡
  ➞ increase in the range of possible ecological niches 🌳

Question 4

• Describe homeostasis

Answer 4

• Homeostasis is the process responsible for regulatuion of the internal environment
• It is responsible for maintaining a balance in:
  ➞ body temperature (thermoregulation) 🌡️
  ➞ water levels (osmoregulation) 💧
  ➞ glucose regulation (glycoregulation) 🍦

Question 5

• Describe ‘thermoregulation’ and explain what the hypothalamus is.

Answer 5

• ‘Thermoregulation’ is the general process responsible for regulating the internal environment
  ➞ which is controlled by negative-feedback mechanisms 🔄️
• The hypothalamus is the body’s temperature monitoring centre within the brain 🌡️
  ➞ which is sensitive to nerve impulses that come from receptors in the skin.

Question 6

• Can you explain what the response (thermoregulation) is to an increase in body temperature? ☀️

Answer 6

• SWEATING 🥵
  ➞ body heat is used to evaporate water in the sweat, cooling the skin
• VASODILATION 🩸
  ➞ increased blood flow to skin, increases heat loss
• DECREASED METABOLIC RATE ✨
  ➞ less heat is produced

Question 7

• Can you explain what the response (thermoregulation) is to a decrease in body temperature? ❄️

Answer 7

• SHIVERING 🥶
  ➞ muscle contraction generates heat
• VASOCONSTRICTION 🩸
  ➞ decreased blood flow to the skin, decreases heat loss
• HAIR ERECTOR MUSCLES CONTRACT 💪
  ➞ traps layers of insulating air
• INCREASED METABOLIC RATE ⚡
  ➞ more heat is produced

Question 8

• What is the importance of ‘thermoregulation’?

Answer 8

• Regulating temperature requires a lot of energy
• Thermoregulation provides enzymes with optimum temperatures,
  ➞ so they work faster
• Thermoregulation is also important for diffusion, as diffusion rates are higher in warmer temperatures.