CH.2: ENERGY SYSTEMS

Flashcards for reviewing energy systems and ATP re-synthesis.

ATP Hydrolysis

The breakdown of ATP that provides energy for muscle contraction.

ATP Stored in Muscle Cells

A small amount is stored in muscle fibers for a quick 'flight or fight' response, but lasts only 1-2 seconds.

Why don’t we just store more ATP?

Because it's highly reactive with water and wouldn't remain stable in cells.

ATP Re-Synthesis

Requires energy, which comes from the food we eat.

To re-synthesize the ATP

To re-synthesize ATP we need to add a phosphate group back onto the ADP.

ATP-PC System (Anaerobic Alactic)

ATP re-synthesis from phosphocreatine (PC) breakdown.

When Do We Use ATP-PC System?

All-out maximum efforts.

Starting Fuel for ATP-PC System?

Phosphocreatine (PC).

of Rxns Involved in ATP-PC System?

1.

Duration of ATP-PC System?

10s.

ATP Produced by ATP-PC System?

1/PC.

Reason the ATP-PC System Stops?

Run out of PC (quickly!).

Glycolytic System (Anaerobic Lactic)

ATP re-synthesis from glucose breakdown

Steps of Glycolysis

Glucose starts to get broken down, enough E! is released which is used to re-generate 2 ATP’s

When Do We Use GLYCOLYTIC SYSTEM?

During high-intensity work

Starting Fuel for GLYCOLYTIC SYSTEM?

Glucose

of Rxns Involved in GLYCOLYTIC SYSTEM?

10.

Duration of GLYCOLYTIC SYSTEM?

Dominates during high-intensity work lasting ~1 min

ATP Produced by GLYCOLYTIC SYSTEM?

2/molecule of glucose

Reason GLYCOLYTIC SYSTEM Stops?

During high-intensity work, the hydrogens that are removed from glucose build up = pain! Otherwise, this system is always operating.

Is the Build-Up of Lactic Acid “Bad”?

A build up of Hydrogen ions (H+) is ‘bad’

Lactic Acid is Your Hero!

The conversion of pyruvate into Lactic acid temporarily prevents H+ build-up (buying you a little more time).

Why are H+’ s “BAD”???

They change the pH of the muscle tissue, making the muscles more acidic.

AEROBIC SYSTEM

ATP re-synthesis from complete glucose breakdown

When Do We Use AEROBIC SYSTEM?

During low-intensity (or “sub-maximal” work)

Starting Fuel for AEROBIC SYSTEM?

Glucose (or fatty acids…or even amino acids if necessary!)

of Rxns Involved in AEROBIC SYSTEM

A lot!

Duration of AEROBIC SYSTEM?

Always the dominant system unless work rate gets too high

ATP Produced by AEROBIC SYSTEM?

36/molecule of glucose

Reason AEROBIC SYSTEM Stops?

During high-intensity work, the body can’t take in enough oxygen to allow this system to work. Otherwise, this system is always operating.

The 3 Stages of AEROBIC SYSTEM

The conversion of pyruvate. The Kreb’s Cycle. The Electron Transport Chain.

STAGE 1 – THE CONVERSION OF PYRUVATE

Each 3-carbon pyruvate enters the mitochondria, where it is further broken down into a 2-carbon acetyl-CoA

STAGE 2 – THE KREB’S CYCLE

Each 2-carbon acetyl-CoA is broken down completely.

STAGE 3 – THE ELECTRON TRANSPORT CHAIN

NADH and FADH are oxidized (lose their hydrogens).

Oxygen's Impact

Oxygen picks up the H+’s (and the electrons) once they’ve gone through ATP synthase