Metabolism
 
 What's Inside  - Metabolism

   Anabolism/Catabolism 
   Anaerobic Metabolism 
  Glycolysis 
  Cori Cycle 
   Aerobic Metabolism 
  TCA Cycle 
  Electron Transport Chain
   Metabolism
The sum of chemical reactions which occur in the body
Calculate Your Metabolic Rate

ATP Adenosine Triphosphate
    What the body uses for energy

Anabolism
Building reactions which require the input of energy.  Examples:
Carbohydrate - linking glucose units together to form and store glycogen.
Protein - linking amino acids together to form proteins.
Lipids - combining fatty acids with glycerol to make triglycerides.

Catabolism
Reactions which breakdown substances to smaller units and release energy.
Carbohydrate - breaking down glycogen to glucose and glucose to ATP
Protein - breaking down proteins to amino acids and amino acids to ATP
Lipids -  breaking down triglycerides to fatty acids and glycerol and using those to resynthesize ATP 

Anaerobic  Metabolism
Anaerobic metabolism does not require oxygen. Anaerobic metabolism is used to produce intense power for a short period of time.  An individual reaches fatigue when the production of lactic acid (lactate) exceeds its removal from the muscle cell.  Anaerobic metabolism relies exclusively on carbohydrate as an energy source.
Glycolysis
    Glucose to Pyruvate >>>  Lactate

Glucose
A six carbon molecule  C6H12O6
C-C-C-C-C-C
|
v
C-C-C  +  C-C-C
|
v
                    2 pyruvate ->  Lactic Acid
C-C-C
C-C-C
and
|
v
             C-C-CoA   +  CO2
             C-C-CoA   +  CO2
2 acetyl CoA + 2 carbon dioxide

CoA is short for coenzyme A whose function is to move compounds from one place to another in the cell.

    Cori Cycle:  lactate is picked up from the muscle by the vascular system and taken to the liver where it is reconverted to glucose.  Glucose then leaves the liver and enters the blood stream to resupply the working muscle.

    Pyruvate to Acetyl CoA
one glucose (6 C's) produced two pyruvates (3 C's) then removed a carbon dioxide from each pyruvate. 

Aerobic Metabolism
Aerobic metabolism requires oxygen, thus it primarily occurs at low and moderate rates of activity.  Aerobic metabolism may use carbohydrates, triglycerides and protein for energy.  Two energy sub pathways makeup aerobic metabolism: Tricarboxylic Acid Cycle [(TCA cycle) also known as the Kreb cycle], and the electron transport chain/system (ETC/ETS)
 

Coenzymes: nicotine adenine dinucleotide (NAD) from the vitamin niacin and
                   flavin adenine dinucleotide (FAD) from riboflavin are used to transport hydrogen electrons from the TCA cycle to the electron transport chain.

NAD -> NADH+H+   = value of 3 ATP

FAD -> FADH2       = value of 2 ATP 

Electron Transport Chain
 The electron transport chain (ETC) is where the trapped H electrons from NADH+H+ and FADH2 are processed to release energy to resynthesize ADP to ATP.   Adenosine-PO3~PO3  (ADP) + [PO3  & energy ] > ATP

Terms to know
glycolysis
glycogenesis
glycogenolysis
gluconeogenesis
ketone
ketosis
lipolysis
lipogenesis
 

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