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Oxidative Energy SourcesMuscle Glycogen-
• 15g/kg x 30 kg = 450g x 4 kcal/g = 1800 kcal
Liver Glycogen-50g/kg x 1.5 kg = 75g x 4 kcal/g = 300 kcal
Blood Glucose-1g/L x 5 L = 5g x 4 kcal/g = 20 kcal
Total: 1800 + 300 + 20 = 2120 kcal
Fat-70 kg x 10% fat = 7 kg x 7700 kcal/kg = 54,000 kcal
Enzymes• Introduction
German for yeast
Proteins acting as catalysts to speed up Rx by the energy of activation
Specificity
Active site = catalytic site + binding site
E + S ES complex E + PNo waste product produced!No enzyme lost!
V max
Km affinity of enzyme for S.
max rate of Rx
Initial
Velocity
loss of S
or
gain in P
Concentration of Substrate
Enzyme Kinetics
Competitive Inhibition
Km Km
V max
Concentration of Substrate
Rate
of
Rx.
Regulation of Enzymes
A) Competitive Inhibition
Similar geometric shape
O.A.A.
Acetyl Co-A
Citrate
Example:
citrate synthase
( - )
C-C |C-C
O
OHO
OH
C-C |C-C |C-C
O
OHOOHOOH
B) Allosteric Regulation
Binds at a site different from active site.
Changes the shape of the enzyme. Increasing or decreasing the ability to react with the substrate.
V maxRate
of
Rx.
Concentration of Substrate
Allosteric Regulation (cont.)
AMPATP
(substrate)
(Enzyme--PFK)
normal activated inhibited
Fructose 6-P Fructose 1-6 P via PFK
3 AA have hydroxylside chains
SerineTyrosine
Threonine
They are polar and
hydrophilic and thus stick outinto the cytosol
D) Increase in the amount of enzyme.
V max
Rate
of
Rx.
Concentration of Substrate
Temperature
Vmax Vmax
pH
Metabolic Pathway
A B C D E1 E2 E3
Final ProductInitial Substrate
Usually first irreversible step is controlled by an allosteric
enzyme.
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