BOB's 1 Flashcards
What is a metabolite?
A substance formed in metabolism or necessary for metabolism.
What are the products of catabolic metabolism?
Building block materials
Organic precursors like acetyl CoA
Biosynthetic reducing power like NADH and NADPH
Energy for cell function ATP
Give an example of a high energy signal and what it activates?
ATP and it activates anabolic pathways.
What is adenylate kinase or myokinase?
An enzyme that turns two low energy ADP molecules into an ATP and an AMP
What is creatine phosphate?
It acts as an energy store in muscles. Glycogen breakdown would be too slow for muscle requirements.
How is creatine phosphate used to store energy?
Creatine is phosphorylated by creatine kinase to form phosphocreatine. Energy is held in the phosphate bond.
When is phosphocreatine r creatine phosphate formed?
When ATP levels are higher. When ATP levels begin to deplete phosphocreatine goes back to creatine and produced an ATP from ADP
Creatine kinase and MI or myocardial infarction.
Creatine kinase has different isoforms found in different tissues.
CK-MM at 70% in heart while CK-MB is at 30%.
CK-MM is 98% in muscle while CK-MB is at 1%.
During MI CK is released from cardiac myocytes and if you find the heart ratio in the blood then that’s indicative of an MI. If you find the skeletal ratio in the blood then that indicates skeletal muscle damage.
What is creatinine?
Creatinine is formed from the breakdown of creatine and phosphocreatine. A constant proportion of the two break down each day unless during muscle wasting.
Creatinine as a clinical marker?
As its formation is based on a constant proportion of muscle mass it can be used to measure muscle mass in an individual as its excreted in the urine and can be measured.
It can also be used as a marker of urine dilution and compared against other substance in urine like hormones in pregnancy to estimate their loss.
