Energy Metabolism and Bioenergetics

Question 1

Nutrients from foods are stored as

Answer 1

carbohydrates, fats and proteins

Question 2

Bioenergetics

Answer 2

The process of producing energy (ATP) in a biological system and using ATP to do work

Question 3

Metabolism

Answer 3

All the chemical reactions in the body

Question 4

Thermodynamics

Answer 4

Energy neither created and destroyed

Question 5

Exergonic reactions

Answer 5

energy-releasing reactions (free energy negative)

Question 6

Endergonic reactions

Answer 6

energy-consuming reactions (free energy positive)

Question 7

Metabolic Pathway- Metabolism

Answer 7

Total of all the catabolic/exergonic and anabolic/endergonic reactions in the system

Question 8

Catabolic pathway

Answer 8

Breakdown of larger molecules into smaller molecules

Question 9

Anabolic pathway

Answer 9

Synthesis of larger molecules from smaller molecules

Question 10

ATP

Answer 10

Metabolic currency in biological tissues

Question 11

Three sources of ATP Production

Answer 11

1. ) Phosphocreatine (PCr)
2. ) Oxidative Phosphorylation ( mitochondrion)
3. ) Glycolysis

Question 12

Phosphocreatine

Answer 12

• Immediate source lasts only a few seconds at maximal flux
• Occurs in the cytoplasm
• Does not require O2, anaerobic metabolism

Question 13

Glycolytic (uses glucose)

Answer 13

• At maximal flux, only lasts up to a few minutes before muscle fatigue occurs
• Occurs in the cytoplasm
• Anaerobic in that oxygen is not used, but pyruvate moves into mitochondria to supportive oxidative phosphorylation

Question 14

Oxidative phosphorylation

Answer 14

• Can support exercise for hours
• Occurs in the mitochondria
• ‘Aerobic metabolism’
• Slower form of ATP production because it is so complexed, however it’s the most efficient

Question 15

ATP-Phosphocreatine (ATP-PCr)

Answer 15

ATP + Cr ⇌ ADP + PCr + H+

• The reaction is bi-directional depending on substrate level concentrations
• During skeletal muscle contraction, there is an ⬆️ in the concentration of ADP and H+ and a ⬇️ in ATP
• If PCr is available, the reaction will work to restore ATP
• PCr replenishment can take between <5-15 mins
• Still used at low and moderate intensity exercise, but can replenish at same time using ATP produced in mitochondria

Question 16

Glycolysis

Answer 16

• When exercise continues for more than a few seconds, ATP regeneration is derived from blood glucose and muscle glycogen stores
• Converts glucose (6 carbons) into 2 molecules of pyruvate ( 3 carbons) and a net of 2 ATP
• PFK is also known as the ‘rate of liminting enzyme’ : regulates the interaction between F6P and F1,6 biphosphate
• In the glycotic process there are also 2 NADH which
  are formed that can be used in aerobic metabolism to produce additional ATP

Question 17

Anaerobic and Aerobic Glycolysis

Answer 17

• If O2 is present (aerobic condition), pyruvate can enter the Krebs cycle

Question 18

Using ATP produces Acid

Answer 18

During exercise ATP is used by:
- Cross-bridge cycling (myosin ATPase)
- Action potentials (Na/K ATPase)
- SR calcium uptake
ATP 'hydrolysis' is A MAJOR SOURCE OF ACID BUILD UP DURING EXERCISE

Question 19

What causes metabolic acidosis in skeletal muscle?

Answer 19

Acidosis develops when the rate of H+ production exceed the rate of H+ removal/buffering

Question 20

Electron Transport Chain

Answer 20

• Complex 1 is a stonger magnet than NADH
• Complex 2 is a stronger magnet than FADH2
• Complex 4 is the strongest of them all for proteins
• O2 is a magnet
• Everytime you have an electron going through the ETC, you pump 3 protons through complex 1,3 and 4
• If your O2 is limited, the mitochondria won’t benefit you