High Energy Compounds Flashcards
What are the three most important high energy compounds?
1) ATP 2) NADH 3) FADH2
How much energy is released in the complete oxidation of glucose?
2850 kJ/mol
Oxidative metabolism occurs in a ____________ fashion, so energy released can be captured as __________ ________ of energy and conserved as high energy compounds such as _________, _______, and _______.
stepwise; discrete packets; ATP, NADH, and FAD
Where does the biological importance of ATP lie?
In the large free energy released when cleaving one phosphoanhydride bond.
How many high energy bonds are in ATP
2
What is ATP when it loses a phosphate group?
ADP
What is ATP when it loses 2 phosphate groups?
AMP
What groups are high energy bonds between?
phosphate and a carbonyl group
What pulls an endergonic reaction that produces ATP to the right?
Coupling the reaction with an exergonic reaction (the exergonic reaction pulls both reactions to completion).
What must be true of coupled reactions for them to operate in the forward direction?
Total delta G must be negative
How long is ATP’s half-life?
seconds to minutes (depending on tissue and needs)
Why does the brain rapidly deteriorate when it is in oxygen deprivation?
The brain only has a few seconds worth of ATP.
What catalyzes the transfer of a high energy phosphate group?
Kinases
What is the storage form of ATP in muscle and nerve cells?
Creatine phosphate (phosphocreatine)
Is the reaction that forms creatine phosphate and ADP from ATP and creatine spontaneous?
No, it is slightly endergonic.
What catalyzes the reaction that forms creatine phosphate?
Creatine kinase
What sort of compounds are ATP, GTP, UTP, and CPT?
High energy phosphate compounds
What pulls the endergonic reaction of phosphate and glucose to glucose-6-phosphate and water to the right?
The reaction of ATP and water to make ADP and phosphate that it is coupled to.
What is the function of converting ATP and creatine to creatine phosphate and ADP?
Storage of ATP
What form are ATP reserves in in resting muscle?
Creatine phosphate (phosphocreatine)
What happens to ATP in muscle under resting conditions?
Concentration of ATP increases, pushing the ATP + creatine→ creatine phosphate + ADP to the right, thereby converting ATP to its storage form.
How much reserve ATP in the form of creatine phosphate does resting muscle contain?
Several minutes worth
What happens to ATP when it comes into contact with water?
Hydrolysis
What are nucleosides that exist at high energy triphosphate compounds used for?
Biosynthesis of proteins and nucleic acids
What is the high energy bond in acetyl CoA?
The thioester bond (the bond between sulfur and the carbonyl).
What does metabolism do to acetyl CoA?
Moves the acetyl group on and off of it (makes and breaks the thioester bond)
What are two molecules that contain thioester bonds?
1) Acetyl-CoA
2) Succinyl-CoA
Which molecule in the Citric Acid Cycle (TCA) contains high energy thioester bond?
Succinyl-CoA
