The breakdown of ATP provides

the energy currency for all forms

of biological work

Bioenergetics

Muscle cell Energy systems

Food Molecules

Mechanical Work

ATP

Energy stored during the

breakdown of food is used

to manufacture a chemical

compound

Contains a lot of energy

Stored in muscle cells

Cells use the energy released

from the breakdown of ATP to

perform work

Bioenergetics

Chemical to Mechanical Energy

ATP is broken down enzymatically to adenosine

diphosphate (ADP) and inorganic phosphate (Pi) to yield

energy for muscle contraction

Bioenergetics

Energy for muscle contraction

ATP

ENERGY

ADP Pi

Release of the myosin cross bridge from actin requires binding of ATP. After ATP binds it is split to

ADP and inorganic phosphate the energy derived from this reaction is used to cock the cross bridge

in preparation for the power stroke. The power stroke is initiated when the myosin cross bridge

binds to actin. The cycle begins again when another ATP binds to myosin

Bioenergetics

Metabolic Systems

1. Phosphagen system

2. Glycolysis

3. Aerobic system

Each system provides energy to make ATP

Bioenergetics

Phosphagen System

Immediate source of energy that can be used to

add a phosphate to ADP

Creatinephosphate

Bioenergetics

Glycolysis

Lactate

Acetyl-CoA

Glucose

G-6-PGlycogen

Occurs inside the cytosol

Glucose 6-phosphate – from

muscle glycogen or from blood

glucose is converted to lactate or

pyruvate producing ATP

Bioenergetics

Krebs/TCA cycle

Occurs in the mitochondria

and involves a series of 8

chemical reactions that

begins and ends with

Oxaloacetate

Bioenergetics

Phosphagen System

Cis-Aconitate

Citrate

Succinyl-CoA

-ketoglutarate Isocitrate

Malate

Fumarate

Succinate

4 H

4 H

4 H

4 H

2 ATP

Oxaloacetate

Acetyl-CoA

Cis-Aconitate

Citrate

Succinyl-CoA

-ketoglutarate Isocitrate

Malate

Fumarate

Succinate

4 H

4 H

4 H

4 H

2 ATP

Cis-Aconitate

Citrate

Succinyl-CoA

-ketoglutarate Isocitrate

Malate

Fumarate

Succinate

4 H

4 H

4 H

4 H

2 ATP

Oxaloacetate

Acetyl-CoA

Oxaloacetate

Acetyl-CoA

Bioenergetics

Electron Transport Chain

Within the mitochorndria

oxidative phosphorylation

occurs in the electron

transport chain (ETC) which

is situated on the inner

mitochorndrial membrane

Bioenergetics

Phosphagen System

NADH

Dehydrogenase

Cytochrome

b-c1

Cytochrome

oxidase ATP

Synthase

The ETC, the final metabolic pathway; it proceeds as a series of chemical reactions in the

mitochondria that transfer electrons from hydrogen atoms NAD and FAD to Oxygen. The

electrochemical energy releases is coupled to the formation of ATP from ADP and Pi

Acetyl-CoA

Mitochondria(engine of the cell)

Bioenergetics

Chemical Energy

Lactate

Acetyl-CoA

Glucose

G-6-PGlycogen

Glucose 36 ATP

KrebsCycle

‘Oxidation’

Glycogen 37 ATP Fat 129 ATP

Fat

Thank you

Questions?