Glycolysis and Metabolism Review

These flashcards cover key vocabulary terms and concepts related to glycolysis, glycogen metabolism, gluconeogenesis, and associated metabolic pathways.

Glycolysis

A metabolic pathway that converts one glucose molecule into two pyruvate molecules, producing ATP and NADH.

Cytosol

The aqueous component of the cytoplasm in which various organelles, proteins, and other cell structures are suspended; glycolysis occurs here.

Pyruvate

The product of glycolysis that can be converted to acetyl CoA or lactate depending on aerobic or anaerobic conditions.

Investment Phase

The initial phase of glycolysis where two ATP molecules are consumed to convert glucose into glyceraldehyde 3-phosphate.

Payoff Phase

The phase of glycolysis where four ATP and two NADH molecules are produced and two glyceraldehyde 3-phosphate molecules are converted to pyruvate.

Hexokinase

An enzyme that catalyzes the first step of glycolysis, transferring a phosphoryl group from ATP to glucose.

Phosphofructokinase

An important regulatory enzyme that catalyzes the third step of glycolysis, forming fructose 1,6-bisphosphate.

Glycogenolysis

The breakdown of glycogen into glucose, occurring primarily in muscle and liver cells.

Gluconeogenesis

The synthesis of glucose from non-carbohydrate precursors, primarily occurring in the liver and kidneys.

Pentose Phosphate Pathway

An alternative pathway for glucose 6-phosphate metabolism that produces NADPH and ribose 5-phosphate.

Non-oxidative Phase

A phase of the pentose phosphate pathway involving reversible reactions that rearrange carbon skeletons.

Anaplerotic Reactions

Reactions that replenish TCA cycle intermediates, such as pyruvate carboxylase.

Proton Gradient

An electrochemical gradient created by pumping protons across the inner mitochondrial membrane during the electron transport chain.

Ketone Bodies

Compounds (acetone, acetoacetate, and β-hydroxybutyrate) produced in the liver from acetyl-CoA; used as an energy source during fasting.

Acetyl-CoA

A central metabolite connecting glycolysis and the TCA cycle, produced from pyruvate.

NADH

A reduced form of NAD+ produced during glycolysis and the TCA cycle, serving as an electron carrier.