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Production of ATP using the Aerobic System

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Page 1: Aerobic system

Production of ATP using the Aerobic

System

Page 2: Aerobic system

Aerobic system of energy production needs oxygen

At onset of activity, although oxygen is present in the muscles there isn’t enough to break down fuels into energy.

So for immediate energy production the anaerobic systems are used ie ATP-PC system

Lactic Acid System

As soon as we start to exercise heart rate and breathing rate increases so more oxygen is getting to the muscles.

Within a few minutes the muscles are supplied with enough oxygen for aerobic respiration to work.

Page 3: Aerobic system

Aerobic energy is used for low to moderate intensity and long duration.

It offers a high energy yield, allowing activity to be maintained for long periods.

Page 4: Aerobic system
Page 5: Aerobic system

Elite athletes may use their aerobic pathways to perform what would be high intensity to lesser athletes.

Page 6: Aerobic system

Aerobic System uses oxygen to break down food fuels.

This gives off a high energy yield.

Carbohydrates and fats

Page 7: Aerobic system

Three stages of the aerobic pathway

Stage 1 : Glycolysis

Stage 2 : Kreb’s Cycle

Stage 3 : Electron Transport Chain

Page 8: Aerobic system

Stage 1 glycolysis

Glycogen

Pyruvic Acid (pyruvate)

Glycolysis

ENERGY

ADENOSINE P P

ADENOSINE P P

P

P

Page 9: Aerobic system

As oxygen is present the pyruvic acid is NOT converted into lactate.

Instead it is converted intoacetyl-coenzyme-A

(CoA)Acetyl Co-A moves to the mitochondria within the muscle cell where energy release now takes place.

Page 10: Aerobic system

Stage 2 Kreb’s Cycle

Takes place inside the matrix of mitochondria.

As Acetyl CoA enters the matrix it triggers a complex cycle of reactions called Kreb’s Cycle.

From these reactions

energy is produced to resynthesise 2 molecules of ATP.

carbon dioxide is formed.

hydrogen is taken to the electron transport

chain.

Page 11: Aerobic system

Stage 3 electron transport chain

Hydrogen is carried to the electron transport chain.

This occurs in the cristae of the mitochondria.

Hydrogen splits into hydrogen ions and electrons.

Hydrogen ions are oxidised to form water.

Hydrogen electrons provide energy for resynthesis of ATP (34 molecules)

Page 12: Aerobic system

Total energy yield from the aerobic

system is

38 molecules of ATP

Page 13: Aerobic system

The aerobic system is the most efficient in energy production.

The by-products (water and carbon dioxide) are easily expelled.

The system relies on the availability of oxygen.

However…

Page 14: Aerobic system

Sub-maximal exercise will predominantly use this system as oxygen can be delivered at a rate to match the demand for oxygen

Page 15: Aerobic system

Unless the body runs out of carbohydrate and fat stores, this system is

unlimited.

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summary

Stage 1

Glycolysis

(Sarcoplasm)

Stage 2

Kreb’s Cycle

(Mitochondria)

Stage 3

Electron Transport Chain

(Mitochondria)

GlycogenPyruvic

AcidAcetyl

Coenzyme A

ENERGY

ADENOSINE P P

ADENOSINE P P

P

P

Acetyl Coenzyme A

ADENOSINE P P

ADENOSINE P P

P

P

ENERGY

Carbon Dioxide

Hydrogen

Hydrogen Water

ADENOSINE P P P

34

ENERGY

Page 17: Aerobic system

Glycogen

Pyruvic Acid

Acetyl Coenzyme

A

Carbon Dioxide

Electron Transport Chain

2ATP

2ATP Glycolysis

34ATP

Water

Krebs Cycle

Oxygen present

Hydrogen

Page 18: Aerobic system

Fats can also be broken down to

produce energy to resynthesise ATP

Page 19: Aerobic system

Triglycerides (stored fat in muscle)

Glycerol and Fatty

AcidsBeta Oxidation

Lipase

Carbon Dioxide

Electron Transport Chain

Energy

130 ATP

Water

Kreb’s Cycle

Acetyl Coenzyme

A

Hydrogen

Page 20: Aerobic system

Lots more ATP can be resynthesised (38 moles of ATP from 1 mole of glycogen).

The body has large stores of muscle glycogen and triglycerides so exercise can last for several hours.

Oxidation of glycogen and fatty acids do not produce any fatiguing by products.

Advantages of the aerobic system

Page 21: Aerobic system

Takes a while for sufficient oxygen to be available to breakdown glycogen and triglycerides.

Therefore this system cannot provide energy for ATP resynthesis straight away or during high intensity activity.

disAdvantages of the aerobic system

Page 22: Aerobic system

How can this system be improved?

Increased muscle stores of glycogen & triglycerides.

Increased number of oxidative enzymes.

Continuous training

Fartlek training

Page 23: Aerobic system

The triathlon is an athletic event that involves performers undertaking a long distance swim, immediately followed by a cycle race and then finally a run of several kilometres.

What would be the major energy sources used by a triathlete? (3 marks)

Briefly explain how these energy sources are used for regeneration of ATP. (5 marks)

Page 24: Aerobic system

Fats

Fatty acids

Glycerol

Triglycerides (sub max 2 marks)

Carbohydrates

Glycogen

Glucose (sub max 2 marks)

What would be the major energy sources used by a triathlete? (3 marks)

Page 25: Aerobic system

Briefly explain how these energy sources are used for regeneration of ATP. (5 marks)Carbohydrates/glycogen broken down into glucose then into pyruvate.

Called glycolysis.

Some ATP is produced.

In presence of oxygen, pyruvic acid converted into acetyl coenzyme A.

Enters mitochondria where Kreb’s cycle takes place.

Carbon dioxide and energy produced to resynthesise 2 molecules of ATP.

Hydrogen is carried to electron transport chain.

Water produced and energy to resynthesise 34ATP.

Page 26: Aerobic system

Considers the importance of each energy system in a particular activity.

Intensity and duration will decide which energy system is used.

Often there will be a combination of all three.

Energy continuum

Page 27: Aerobic system

Energy continuum

Example: Marathon RunnerATP-PC System – Start

of race.

Aerobic System – Majority of race.

Lactate Anaerobic System – Sprint finish.

Page 28: Aerobic system

Example: Midfield in football

ATP-PC System – Sprinting for the ball.

Lactate Anaerobic System – High intensity work, chasing ball, moving into space, dribbling with ball.

Aerobic System – Less intense periods when play does not involve the player. Time to recover using aerobic system.

Page 29: Aerobic system

Energy continuum

Page 30: Aerobic system

Energy supplied against time

A = ATP-PC - Lactic Acid threshold. The point at which ATP-PC system is exhausted and the lactic acid system takes over.

B = Lactic Acid - Aerobic threshold. The point at which the lactic acid system is exhausted and the aerobic system takes over.

ATP-PC

Lactic Acid

Aerobic

Page 31: Aerobic system
Page 32: Aerobic system

Phosphocreatine broken down by creatine kinase.

Energy released is used to resynthesise ATP.

Aerobic system used for recovery.

Page 33: Aerobic system

THE EFFECTS OF RELIEF PERIODS FOLLOWING INTERMITTENT EXERCISE ONTHE LEVELS OF ATP-PC STORES IN MUSCLE.

ATP-PC STORES

TIME

WORK RELIEF WORK RELIEF WORK

i) ATP-PC stores are exhausted rapidly in high intensity/short duration activities. 8-9 secs in average individual

ii) Possible to achieve regeneration by up to 50% after 30 seconds rest

iii) Can regenerate in game by walking or standing but supplies only go back up to approx 90% then down then back up to approx 80% then down etc.

Page 34: Aerobic system

At low intensity, the aerobic system is used.Fats, glycogen and carbohydrates broken down.Acetyl Coenzyme-A enters Kreb’s cycle in mitochondria.Carbon dioxide produced and a small amount of energy to resynthesise ATP.Hydrogen taken to electron transport chain.Lots of energy given off.As intensity increases, there will be a lack of oxygen.So ATP produced through lactic acid system.Glycogen broken down into pyruvic acid giving off energy to resynthesise ATP.As no oxygen present pyruvic acid converted to lactate.

Page 35: Aerobic system

In part (d)(ii), a disappointingly large proportion of candidates suggested that the energy systems somehow work in a sequence suggested by interpreting the x-axis of Figure 3 as simply duration of a single event, rather than as duration of differing events. Better answers, though rarer, did manage to suggest that a long-

distance run was predominantly an aerobic activity, which became anaerobic

as the intensity increased.

Page 36: Aerobic system

RATE OF ENERGY PRODUCTION

% O

F M

AX

IMU

M R

AT

E O

F E

NE

RG

Y P

RO

DU

CT

ION

TIME

2 SECS 10 SECS 60 SECS 2 HOURS

OVERALL PERFORMANCE

ATP-PC SYSTEM

LACTACID SYSTEM

ATP STORE

AEROBIC SYSTEM