Energy Reactions In Cells Flashcards
Define metabolism
Metabolism is the set of processes which derive energy and raw material from food and use them to support growth, repair and activity of the tissues to sustain life
Describe the relationship between catabolism and anabolism
Catabolism = breakdown, (oxidative) releases energy and H atoms (reducing power) for anabolism
Anabolism = synthesis, (reductive)
Define exergonic and endergonic
Exergonic: release energy (delta G<0)
Endergonic: require energy(delta G >0)
What is the function of H-carrier molecules?
When fuel molecules are oxidised, electrons and protons are transferred to carrier molecules. Act as carriers of “reducing power” for ATP production and biosynthesis
Name 3 carrier molecules
NAD+ (NADP + H+), NADP+ (NADPH + H+), FAD (FADH2)
What is the oxidation of NADH used for?
ATP synthesis
What is the oxidation of NADPH used for?
Biosynthetic reduction
What enables the flow of energy to be controlled?
ATP is stable in the absence of specific catalysts
How is energy released from ATP?
Exergonic reactions drive synthesis of ATP, High energy of bond hydrolysis, when bond breaks releases a lot of energy
Why can’t ATP be used as an energy store?
Limited amount of ADP, only enough for a few seconds, must be a cycle, so only a carrier, not a store
Name 2 energy stores in the body
Triglycerides
Glycogen
ATP is an energy currency- NOT A STORE
What is the equation for creatine phosphate?
Creatine + ATP —> creatine phosphate + ADP (via creatine kinase)
How can monitoring creatine metabolism be clinically useful?
Creatine kinase activity can be a marker of muscle damage. Is a sensitive serum marker for myocardial damage and suspected muscle injury. CK-MB is used as a marker for cardiac muscle damage.
What are the 2 subunits of CK? What are the 3 combinations of these subunits?
M and B. CK is cytosolic enzyme so will appear in the blood soon after cell damage.
3 isoform combos: MM, MB and BB
What is creatinine?
Breakdown product of creatine (and creatine phosphate)
Excreted via kidneys
Used to assess kidney function, provide a measure of muscle mass and estimate urine dilution
