Energy Energy SystemsSystems

Here we go again

Three Key Energy Nutrients

1. 2. 3. – _______________ is the usual form in which carbs are

digested in humans– It is stored within the skeletal muscle and liver as

_____________– Glucose can be broken down by the body to produce

an _______________________We use these through bioenergetic conversion to

carry out physical activity

ATP

• The end result of the breakdown of nutrients is the production of various amounts of adenosine triphosphate (ATP).

ATP- the science• ATP is the _______________ energy source for

muscular contraction.• An ATP molecule consists of an adenosine

molecule bonded to ____ phosphate (P) groups.

• ATP molecules are supplied by chemical reactions that take place in the _________________ found in muscle cells.

• To release the energy, a phosphate molecule breaks away from the phosphate group through hydrolysis to form adenosine diphosphate (ADP)

Adenosine P P P Chemical reaction

Adenosine P P

HEATHEAT

ENERGYENERGY

P

ATP = ADP + Energy + P

• ADP requires ___________ to become ATP again!

A P PEnergy

in

PA P P

Energy

out

Note:

Revisiting the Sliding Filament theory for Application of ATP Consumption

• Breaking ATP into ADP releases energy and allows _________________________formation to occur between the myosin and actin filaments inside the muscle.

Two Energy Systems

1. Aerobic– An energy system which is used in

prolonged continuous activity in the presence of oxygen and does not produce lactic acid.

2. Anaerobic– Energy systems that do not rely on the

immediate use of oxygen. There are two types of anaerobic energy systems.

3 Metabolic PathwaysAnaerobic Alactic (ATP-CP) or (ATP-PC)• A short term energy of both fast and

slow twitch muscle fibres that does not require oxygen and does not produce lactic acid.

Anaerobic Lactic (glycolysis)• A fast twitch muscle energy system

which does not require the immediate use of oxygen but does produce lactic acid.

Next Class:Aerobic (cellular respiration)

Anaerobic Alactic - ATP-CP SystemAn immediate - _______________phosphate system

Involves _____ power output activities that require an immediate high rate of energy production for a short period of time.

Involves activities such as

Adenosine PP P

HEATHEAT

ENERGYENERGY

• As muscle contraction begins, the body’s metabolism may not be able to supply ATP to the contracting muscle cells as rapidly as required…

• The body must then make use of _______________________. – (the chemical reaction that must occur for contraction)

ADP

Creatine phosphate serves as _____________________________for muscles as it is broken down into creatine and

phosphate.

CP-

ATPATPENERGYENERGY

Adenosine P P P P / CP / CCreatineCreatine

(on its own)(on its own)+

ATP- Potential EnergyThe free

phosphate ions bonds with ADP to produce ATP and leave behind creatine.

The new ATP molecule is stored as _____________________________.

Potential

Energy

Anaerobic Alactic Characteristics

•Oxygen is• Lactic acid is•Only a ___________ amount of ATP and CP is stored in muscle fibres;• Uses very large amounts of energy in a short period of time;• The rate of recovery is relatively rapid. After a brief rest, the system is recharged and ready for the next sprint;• The system can only provide energy for muscles for the first ___________ seconds of high intense activity;• Uses both fast and slow twitch muscles;•Work output is relatively high.• Formula:

If an athlete must continue vigorous work a ___________ energy system uses a complex biochemical process which __________________________________________________.

CarbsCarbs

Glucose/glycogenGlucose/glycogenENERGYENERGY

Lactic Lactic AcidAcid

ADP + P ATPADP + P ATP

Anaerobic Lactic - GlycolysisAnaerobic Lactic - Glycolysis

Glycolysis

• Glycolysis breaks _____________ down into energy (ATP)

• Glucose is plentiful throughout the body• Glycolysis is the ____________ sequence of

reaction in the full metabolsim of glucose• Therefore glycolysis alone will allow the body

to be active for medium term activities

Glycolysis- produces 2 ATP

Energy is produced with a buildup of________________Energy is produced with a buildup of________________

1 Glycogen molecule

Glycolysis

Pyruvate/Lactic Acid

A

P

P

P

A

P

P

P

Characteristics of the Lactic Acid System

• The energy source is entirely __________________;

• Oxygen is• Energy is provided for

• Uses predominately fast twitch muscle fibres• Work output is moderate• Used in sports such as football, basketball and

hockey.• Formula:

The Effects of Lactic Acid

During intense exercise, lactic acid builds up in the blood __________________________.• As lactic acid builds up an athlete will reach their anaerobic threshold (AT).

– This is the point where a person begins to feel discomfort and a ________________in their muscles

– the muscle loses it ability to contract resulting in _____________________.

• As work increases, the body reaches the:

• At this point the anaerobic system can no longer keep pace with the increasing requirements of the muscles.

• You either___________________________________

Low

Exercise Intensity

Moderate

The anaerobic thresholdis the highest intensity ofworkload at which lactateclearance still keeps pacewith lactate production.

Once this level is reachedthe intensity level mustdecrease to reduce theamount of lactic acid buildup

High

The Effects of Lactic Acid• Lactic acid causes _____ changes in the

muscle fibres and they can no longer respond to stimulation (___________________________________).

• Lactic acid interferes with cross- bridge bonding by limiting the strength of the fibre contraction on the Actin.

• When lactic acid accumulates, extreme fatigue sets in and __________________develops.Oxygen debt is the reason you must breathe

The Effects of Lactic AcidThe Effects of Lactic Acid

Oxygen Debt• Oxygen debt refers to post exercise oxygen

consumption where the body needs to _________________its debt incurred after the exercise is over

• You will notice that even after you are done racing you will continue to breath hard.

• At this point your body is still trying to repay the oxygen debt that was created when you were working hard.

• After you stop ________________, your body needs extra oxygen to burn up the excess lactic acid and return your energy reserves to normal.

• Lactic acid cannot be removed until

Cori Cyle• After exercise where lactic acid has built up you

need to convert it back to ____________________• converting to ______ is important for future

conversion to glucose and glycogen for future anaerobic use

• In the muscle_________becomes __________ which can be transported in __________

• lactate is transported by the blood to liver where most of it is converted back to glucose, from which glycogen is formed in a process called __________________

• about one-sixth of the lactate is oxidized to carbon dioxide

The Effect of Training on the Lactic Acid System

At any level of work, the rate of lactic acid build-up is decreased through training.

How do you know if your workouts are pushing your Anaerobic Threshold?

• Elite athletes use the _____________which requires a hand-held device that directly measures blood lactate concentration. The corresponding heart rate at the AT gives you a convenient way of monitoring your workouts.