metabolism - finish on laptop

Question 1

metabolism =

Answer 1

collective term for all the chemical reactions in the body

• metabolism of a food source (substrate) is generally carried out to release potential energy ‘locked’ inside chemical bonds

Question 2

a kilocalorie =

Answer 2

amount of heat required to raise 1g of H20 by 1 degrees Celsius

Question 3

Substrates -

Answer 3

= substance that is the starting point for a reaction
• act as fuel for exercise - energy from chemical bonds in food are stored as ATP

• 3 primary energy substrates…
◦ Carbohydrates = main fast acting substrate
◦ Fats = endurance long acting substrate
◦ Proteins = if other two are not available

	‣ At rest use 50% carbohydrate and 50% fat 
	‣ During short exercise use more carbohydrates 
	‣ During long exercise isle more fats

Question 4

how are food calories counted:

Answer 4

4kcal/g for protein

4kcal/g for carbs

9kcal/g for fats

Question 5

adenosine triphosphate (ATP) synthesis pathways:

Answer 5

• 7.3 Kcal per bond broken
• ATP is not a long-term energy store - body must constantly synthesise new ATP
◦ There are three ATP synthesis pathways…

1. ATP-phosphocreatine system
2. glycolytic system
3. oxidative system

Question 6

Measurements of energy:

Answer 6

• kilocalorie (Kcal or cal)… 1000 cal = 1 Kcal = 1 calorie
◦ 1 calorie is the amount of heat required to raise 1g H20 by 1°C
‣ Measured from 14.5-15.5 °C