Energy reactions in cells Flashcards
Metabolism definition
The set of chemical processes which derive energy from food and use them to support growth, repair and activity of the tissues to sustain life
Metabolic pathways
Involve several steps with different intermediates and are interconnected with other pathways
What type of energy is used to drive energy requiring activities in the body?
Chemical bond energy
Exergonic
Release energy - has a negative delta G
Endergonic
Require energy - has a positive delta G
Carrier molecules
When fuel molecules are oxidised, electrons and protons are transferred to the carrier molecules so they are reduced
Concentration of carrier molecules
Total conc. of oxidised and reduced forms is constant as they are in a cycle of oxidative and reductive processes
How is the oxidised form of a carrier molecule converted to the reduced form?
Addition of two protons and electrons
Why is ATP a good energy carrier?
The phosphate bonds store a lot of energy and are stable unlike other high energy bonds. It is also stable in the absence of specific catalysts
High energy signals
Activate anabolic pathways - use energy
ATP, NADH, NADPH, FAD2H
Low energy signals
Activate catabolic pathways to release energy
ADP, AMP, NAD+ NADP+, FAD
AMP as a low energy signal
Strong signal for low energy as it is made quickly by myokinase. This increase ATP generation by glycolysis
Creatine phosphate
Used to produce more ATP by reacting with ADP to produce ATP and creatine. Catalysed by creatine kinase - reversible reaction
Creatine kinase as a marker
Used to detect muscle damage as it will appear in the blood
Creatinine
Usually produced in small amounts through metabolism of creatine or phosphocreatine