glycogen metabolism and glycolysis Flashcards
What are the main roles of carbohydrates in the body?
Energy storage, structural components, coenzyme components, and essential for DNA replication.
how is glycogen stored in the body?
Glycogen is a multi-branched polysaccharide of glucose stored mainly in the liver and skeletal muscle
what enzyme breaks down glycogen and what product does it yeild?
Glycogen phosphorylase breaks down glycogen, yielding glucose-1-phosphate.
Which hormones regulate glycogen metabolism, and how?
Insulin promotes glycogen synthesis, while glucagon and adrenaline stimulate glycogen breakdown in the liver and muscle, respectively.
what is glycolysis and what are its end products ?
Glycolysis is the breakdown of glucose to pyruvate, producing a net gain of 2 ATP and 2 NADH molecules.
What role does phosphofructokinase play in glycolysis?
It is a key regulatory enzyme that controls glycolysis, influenced by ATP, AMP, H⁺, citrate, and fructose-2,6-bisphosphate.
How is glycolysis regulated at the level of pyruvate kinase?
Pyruvate kinase is regulated by allosteric interactions and feed-forward stimulation by fructose-1,6-bisphosphate; it is inhibited by ATP and activated by fructose-1,6-bisphosphate.
how does glycogen synthesis differ from glycogen breakdown ?
Glycogen synthesis is not simply the reverse of glycogen breakdown; it involves different enzymes and pathways.
What happens when blood glucose levels are low?
Glucagon is released, stimulating glycogen breakdown and inhibiting glycogen synthesis in the liver to release glucose into the bloodstream.
What is the significance of NADH produced in glycolysis?
NADH serves as an electron carrier for the electron transport chain, which helps produce ATP.
