Energy Production

You don’t have to copy the red writing

When a phosphate group splits off ATP it releases energy. It is life’s energy currency.

ATP is essential for cellular metabolism.

3 Methods of energy production in animals

• Anaerobic (no oxygen) – fast short burst of energy (sprints)–Creatine phosphate

–Anaerobic

• Aerobic (requires oxygen) – long slow burst of energy (endurance)

3 Methods of energy production• Creatine phosphate restores ADP to

ATP by donating a phosphate group directly. For ~15 second bursts of energy. Uses no oxygen.– Creatine phosphate + ADP + Pi Creatine

+ 1 ATP

• Anaerobic (Lactic Acid System) –produces ATP and lactic acid. For 30-60 second bursts of energy. Uses no oxygen.– 2 Pyruvic acid + 2ADP + 2Pi Lactic acid + 2

ATP

• NOTE: 2 Pyruvic acids are produced per glucose molecule

• system is also known as anaerobic glycolysis.

NOTE

• In plants, yeast and bacteria anaerobic respiration produces ALCOHOL not LACTIC ACID.

• This process is called fermentation

• This is how we produce alcoholic beverages.

3 Methods of energy production

• Aerobic – fully burns glucose. Produces water, CO2 and ATP. For endurance rather than strength activities. It is a slower process than anaerobic respiration but it produces 18 times more ATP (36 per glucose compared to 2).– Glucose + O2 36 ATP + CO2 + Water

3 Methods of energy production

• Creatine phosphate (Also known as ATP-CP or ATP-PC) – restores ADP to ATP by donating a phosphate group directly. For ~15 second bursts of energy. Uses no oxygen.– Creatine phosphate + ADP + Pi Creatine + 1 ATP

• Anaerobic (Lactic Acid System) –produces ATP and lactic acid. For 30-60 second bursts of energy. Uses no oxygen.– 2 Pyruvic acid + 2ADP + 2Pi Lactic acid + 2 ATP

• Aerobic – fully burns glucose. Produces water, CO2 and ATP. For endurance rather than strength activities. It is a slower process than anaerobic respiration but it produces 18 times more ATP (36 per glucose compared to 2).– Glucose + O2 36 ATP + CO2 + Water

An Analogy• Anaerobic energy production is like using

a Credit Card with a small limit. It is quick and easy to use but leaves you in (oxygen) debt and limits your spending.

• Aerobic energy production is like getting cash out by going to a bank teller (as opposed to

using EFTPOS or an ATM). It takes you longer but you can get more out and you aren’t left in debt.

Which system suit which sports?

• 100m sprint

• 200m to 400m sprint

• 800m run

• Marathon

Oxygen debt • After we use anaerobic respiration we have

to:– restore our glycogen (chains of glucose) levels,– re-synthesise creatine phosphate – and build up our stored supply of ATP. The amount

of oxygen require to do this is called oxygen debt.– convert lactic acid back to pyruvic acid,

• Example: If you do something that requires 6L of oxygen (to do the things above) but you only take in 2L then your oxygen debt is 4L.

The difference between Oxygen Debt and Oxygen Deficit

• Oxygen deficit – is the process of getting into debt

• Oxygen debt – how much oxygen needs to be repayed

Alactic Debt and Lactic Debt (pages 40 and 41)

• Oxygen debt has two portions:

– Alactic Debt – portion of debt needed to restore Creatine Phosphate

– Lactic Debt – the portion of the debt need to turn Lactic Acid into CO2 and Water.

Fatigue

• Psychological fatigue – when your muscles CAN function but mentally you can’t go on.

• Physiological fatigue – your muscle are physically unable to contract anymore.

The Lactic Acid fatigue myth• Most people will tell you that Lactic Acid causes

physiological fatigue. This is not true.

• A muscle fibre that is totally immersed in Lactic Acid can still contract. Therefore it CAN’T be responsible for fatigue.

• Lactic Acid might act as a signal that indirectly tells your brain that your muscles are getting fatigued.

Photosynthesis

• Is the process in plants that converts sunlight into chemical energy.

• The equation for photosynthesis is:

• Or using chemical symbols:

carbon dioxide + water + light energy → glucose + oxygen + water

6 CO2(gas) + 6 H2O(liquid) + photons → C6H12O6(aqueous) + 6 O2(gas)

NOTE

• The equation for photosynthesis is the reverse of the equation for aerobic cellular respiration.