Thompson in class Flashcards
Directors of metabolism?
Catabolic and Anabolic.
need ATP and NADH for biosynthetic pathways and create during catabolic.
Why is ATP referred to as high energy molecule?
Upon hydrolysis, products are more stable than ATP. Products are ADP and Phosphate. Greater tendency to want to move toward hydrolysis.
due to
- charge repulsion
- resonance stabilization of phosphate
- given aqueous condition of blood in cell, water binds better when have this phosphate than ATP.
What is important form of cellular energy transformation
Phosphoryl transfer potential is an important form of cellular energy transformation.
First step of glycolysis?
Glucose + Pi –> glucose-6-P + H2O.
catalyzed by hexokinase (in liver)
What is metabolism?
ability to harness energy from various sources and channel it into biological work
Energy is derived by doing what to food?
Oxidation, yielding glucose and amino acids and triglycerides of lipoproteins in the bloodstream. Then triglycerides are broken down into fatty acids and glycerol in the bloodstream by an enzyme.
What happens to excess fuel after a meal?
excess fuel is stored as glycogen and adipose triglyceride, and amino acids are converted to muscle protein.
How is food oxidized to produce ATP?
TCA cycle - oxidizes Acetyl CoA, produces CO2, and electrons are passed to NAD+ and FAD. Then NADH and FADH2 transfer the electrons to O2 via the electron transport chain.
Then energy from this transfer of electrons is used to produce ATP by the process of OXIDATIVE PHOSPHORYLATION.
What is oxidative phosphorylation?
The coupling of electron transport with ATP synthesis is called oxidative phosphorylation. Transfer of electrons for the nadh or fadh2 which are reduced coenzyme, to carriers along electron transport chain creates proton gradient that allows ATP to be formed.
What is the difference between the outer and inner mitochondrial membranes?
“the outer membrane contains special channels (formed by the protein porin), making it freely permeable to most ions and small molecules, the inner membrane is a specialized structure that is impermeable to most small ions”
Inner membrane also has lots of protein involved in oxid. phosph.
What occurs in matrix of mitochondria?
“Has lots of protein responsible for oxidation of pyruvate, amino acids, and fatty acids (by β-oxidation) as well as those of the tricarboxylic acid (TCA) cycle.
“The synthesis of glucose, urea, and heme occurs partially in the matrix of mitochondria.
“In addition, the matrix contains NAD+ and FAD (the oxidized forms of the two coenzymes that are required as hydrogen acceptors), and ADP and Pi, which are used to produce ATP. [Note: The matrix also contains mitochondrial DNA (mtDNA) and RNA (mtRNA) and ribosomes
What is the net yield of ATP in oxidative phosphorylation?
3 mol ATP per mol NADH oxidized,
2 mol ATP per mol FADH2 oxidized.
Where does oxidative phosphorylation take place and where is the ATP? How does it get transported?
It is a mitochondrial process so ATP is in the mitochondrial matrix and transported out to the cytosol by ATP / ADP translocase.
What are the inhibitors that block electron transport down the ETC?
Amytal reotenone, antimycin A, sodium azide.
All block flow of electrons from substrate to oxygen.
What causes proton leak which prevents production of ATP coupled with the ETC?
Uncoupling proteins allow protons to re-enter the mitochondrial matrix
