Energy Reactions In Cells Flashcards
Metabolism
Set of processes which derive energy and raw materials from food stuffs and use them to support repair, growth and activity of the tissues of the body to sustain life
Describe the 2 types of metabolic pathways
Catabolic: Breakdown of large molecules into smaller ones, release energy, OXIDATIVE (release H)
Anabolic: Synthesise larger cellular components from intermediary metabolites, use energy, REDUCTIVE (use H released in catabolism)
Define exergonic, endergonic
Exergonic: release energy (G<0)
Endergonic: require energy (G>0)
What is the H-carrier redox cycle ?
REDUCTION
Biosynthetic reduction: NADPH + H+ ➡️ NADP+
ATP synthesis: NADH + H+ ➡️ NAD+
Why do cells need a continuous supply of energy?
ADP is a carrier and only exists in small amount. Therefore a constant supply is needed.
How much ATP does the human body contain at any moment in time?
~250 g ATP
Outline high and low energy signals
High: Activate anabolic pathways
-ATP
-NADH
-NADPH
-FADH2
Low: Activate catabolic pathways
-ADP,AMP
-NAD+
-NADP+
-FAD
AMP is an activator of…
AMP dependent kinase:
Regulates gene expression switching from anabolic to catabolic pathways
Equation for producing creatine phosphate
Creatine + ATP ➡️ Creatine Phosphate + ADP
Enzyme: Creatine kinase
When is creatine phosphate formed ?
When ATP conc. is high
What is creatine kinase used for ?
Marker for muscle damage
Why is creatine kinase appropriate as a marker?
It is a dystopia enzyme that appears in blood soon after cell damage
What are the 3 different iOS form combinations of M and B in the subunits of creatine kinase?
MM, BB, MB
CK-MB: Used to be a marker for cardiac muscle damage (now superseded by cardiac specific troponin tests)
CK activity: Sensitive marker for any condition that causes myocyte damage (e.g. myopathy)
What is creatinine?
Breakdown product of creatine (& creatine phosphate)
-Creatinine excretion per 24hr is proportional to muscle mass of the individual
-Creatinine conc. in urine is a marker of urine dilution
