Download Chapter-4 part-2 Energy Metabolism

Chapter 4
Enzymes and metabolism
part II
Outline
• Names of enzymes & types of reactions
• ATP Production
• Synthetic Pathways
Enzymes
• Normally end in “ase”
• Normally are proteins
• “Isozymes” may look
different but catalyze
the same reaction
General types of reactions
• Oxidation-reduction
• Add or subtract e- or H+
• Hydrolysis-dehydration • Add H20
• Remove H20
• Transfer of groups
• Exchange, add, or remove
• Ligation
• Link together
Some examples of reactions
Steps of ATP production
1
2
3
4
Glycolysis
GLUCOSE
PYRUVATE
Site of Citric Acid Cycle
Citric Acid Cycle
or Krebs Cycle
Electron Transport System
Oxidative
Phosphorylation
= synthesis of ATP
Using the electron
Transport system.
Chemiosmosis
• Proteins of mitochondria have 2 purposes, to
– Transport electrons
– Transport hydrogen atoms
Summary: Energy Yield from cellular
respiration
Final hydrogen
acceptor
is oxygen!!
When ATP is broken down this reaction
releases free energy.
• Is this reaction exergonic or endergonic.
• How would you measure free energy?
• ATP can then yield 7-12 kcal/mole ATP
What happens to ATP production without O2?
What do we call metabolism without oxygen?
Anaerobic Metabolism
aerobic
to
30-32 ATPs
DECREASES
anaerobic
No O2!
2 ATPs
Anaerobic Fermentation!
Lactic acid fermentation
Alcohol fermentation
BIG BIOMOLECULES CAN BE BROKEN DOWN AND USED FOR ATP
SYNTHESIS
• Glycogenolysis
• Lipolysis
• Deamination
BIG BIO
Glycogenolysis:
Energy from stored carbohydrates
• Glycogen to glucose
• Energy 4 kcal/gm
Lipolysis:
Energy from fat
• Beta-oxidation
• 9 kcal/gm fat
• Excess Beta-oxidation
can lead to
“ketone bodies”
Energy from proteins:
Typically surplus proteins
but sometimes not from surplus
Aneroxia Nervosa
Synthetic pathways
• Glycerol or amino acids*
• Glucose to
• Glucose to
to Glucose
* gluconeogenesis
Glycogen
*glycogenesis
Glycerol
Triglycerides
• Acetyl CoA to
Fatty acids
Glycogenesis
Synthesis of glycerol and fatty acids
The End