Energy and metabolism

Question 1

definition of Energy?

Answer 1

“the ability to do work”

Question 2

different types of Energy?

Answer 2

Heat, Mechanical, Chemical, Electrical and sound

Question 3

what is the law of conservation of Energy?

Answer 3

There is a finite amount of energy in the Universe. Energy cannot be created or destroyed, but can be transferred from one form to another

Question 4

what is the best energy source in?

Answer 4

Fat intake
carbohydrate intake
protein intake
alcohol intake

Question 5

what is the best energy source out

Answer 5

resting metabolic rate

thermic effect of feeding

physical activity energy expenditure

Question 6

energy balance is?

Answer 6

energy storage=energy intake-energy expenditure

Question 7

what is the law of Thermodynamic spontaneity?

Answer 7

energy will be transformed into:

1. A random disordered or dissipated form unavailable to do work (known as entropy, ∆S)
2. Free energy ∆G and-
3. Heat energy (known as enthalpy, ∆H)

Question 8

what is the second law of thermodynamics?

Answer 8

∆G = ∆H - T∆S
which means:
∆G= change in free energy
∆H= change in enthalpy (change in heat energy)
T= absolute temperature ( ̊K)
∆S= change in entropy (change in random energy)

Question 9

what is ΔG, change in free energy?

Answer 9

The definition of ΔG in a biological reaction is the difference in free energy content between the reactants and products

Question 10

what is -ΔG?

Answer 10

Expend energy from CHO, Fat, Protein

Question 11

what is +ΔG?

Answer 11

Store energy from CHO, Fat, Protein

Question 12

what is an exergonic and endergonic reaction?

Answer 12

Endergonic Reaction: a reaction that uses energy

Exergonic Reaction: a reaction that produces energy

Question 13

how much ATP is stored in the body?

Answer 13

•Concentration in the cell:~5 mmol/kg
•Muscle mass average man (70 kg): 30 kg
•ATP in average man:150 mmol≈76 g
equivalent of a mars bar

Question 14

what is the amount of ATP we use at rest?

Answer 14

–~10 million molecules ATP –for EVERY cell
•~1014 cells (100 trillion cells)
–EVERY second

Question 15

what is the concentration of ATP in the cells vs ATP breakdown during sprinting and how long does it take us to turnover ATP (resynthesise)?

Answer 15

• Concentration in the cell:~5 mmol·kg-1
• ATP breakdown (sprinting):~2.5mmol·kg-1·sec-1
• ATP turnover: every 2 sec!

Question 16

how is ATP re-synthesised?

Answer 16

–ATP + H2O → ADP + Pi + H+ energy for work + heat (ΔG = -31 kJ / mole)
–ADP + Pi + H+ + energy from food → ATP + H2O heat

Question 17

Energy: Food: what happens to any excess calories?

Answer 17

•Any excess calories:
–Fat: 
•stored in adipose tissue
–Carbohydrates: 
•stored as fat in adipose tissue
–Protein:
•stored as fat in adipose tissue
–Alcohol:
•stored as fat in adipose tissue

Question 18

Fat as a substrate for ATP re-synthesis?

Answer 18

• Fat is the preferred form of energy for storage and oxidation
• ~10-25% of body weight
• ~66% of energy supply (ATP resynthesise) at rest

Question 19

Glucose as a substrate for ATP re-synthesis?

Answer 19

• Glucose is needed by the brain (always) and during exercise
• ~100 g in liver and ~300-750 g in skeletal muscle

•100% of energy supply to brain, and main source of energy supply (ATP resynthesise) during higher intensity exercise

Question 20

where is fat stored in the body?

Answer 20

muscles: 300 g
blood: 4-5 g
adipose: 12000 g+

Question 21

where is carbohydrates stored in the body?

Answer 21

muscles: 300-750 g
blood: 4 g
Liver: 100 g

Question 22

Metabolism in the creation of ATP

Answer 22

1. Take substrate with lots of hydrogens / electrons
   - Take off hydrogen atoms / electrons
2. Transport electrons from one electron carrier to the next
   - Energy released, used to pump H+ over a membrane
3. Use the energy of the resulting H+-gradient
   - by coupling to ATP-synthase creating ATP

Question 23

what happens to energy stored in food during metabolism?

Answer 23

energy stored in food → energy stored in ATP

Question 24

what does muscle glycogen and liver glycogen turn into and what does it go through?

Answer 24

Glucose

Glycolysis (2 ATP)

Question 25

what does Glycolysis lead to and what enzymes are involved?

Answer 25

Glucose turns into Lactate or acetyl-CoA with the presence of O2 due to lactate de hydrogenase turning pyruvic acid via phosphofructokinase and turns into acetyl-CoA by acetyl-Coenzyme A combining with pyruvic acid

Question 26

what happens to acetyl-CoA?

Answer 26

it enters the citric cycle(2 ATP) as citric acid and and produces H+ and combines with FAD and NAD to form FADH+ and NADH+ and enters electrolysis(electron transfer)

Question 27

what happens in the Electron transfer?

Answer 27

FADH+ and NADH+ are electrolysed and produce Water by combining with O2 and the energy created is used to synthesis 34 ATP