The Citric Acid Cycle - Lecture 17 Review

A collection of flashcards summarizing key terms and concepts from the lecture on the Citric Acid Cycle.

Citric Acid Cycle

A key metabolic pathway that involves the oxidation of acetyl-CoA to produce energy in the form of ATP and reduced coenzymes.

Acetyl-CoA

A two-carbon molecule that is the starting point for the citric acid cycle, formed from pyruvate.

Oxidative Phosphorylation

The final stage of cellular respiration where ATP is produced using the energy derived from the transfer of electrons.

NADH

A reduced coenzyme that carries electrons to the electron transport chain.

FADH2

Another reduced coenzyme produced in the citric acid cycle that also carries electrons.

Citrate

The first product of the citric acid cycle formed from the combination of acetyl-CoA and oxaloacetate.

Isocitrate

A product formed from citrate by the action of aconitase, which involves rearrangement of its constituents.

a-Ketoglutarate

A key intermediate in the citric acid cycle formed from isocitrate, producing NADH and CO2.

Succinyl-CoA

Another intermediate formed from a-ketoglutarate which further contributes to the production of ATP or GTP.

GTP

A molecule similar to ATP that is produced during the citric acid cycle, which can be converted to ATP.

Regulation of the Citric Acid Cycle

Control mechanisms that affect the activity of the cycle, primarily involving key enzymes such as pyruvate dehydrogenase.

Aconitase

An enzyme that catalyzes the conversion of citrate to isocitrate in two steps.

Feedback Inhibition

A regulatory mechanism where the end product inhibits an upstream process, often involving high energy molecules.

Pyruvate Dehydrogenase Complex (PDH)

A multi-enzyme complex that converts pyruvate into acetyl-CoA.

Allosteric Regulation

Control of an enzyme's activity by the binding of substances at sites other than the active site.

Mitochondria

The organelles where the citric acid cycle and oxidative phosphorylation take place in eukaryotic cells.

Electron Transport Chain

A series of protein complexes located in the inner mitochondrial membrane that transfers electrons and creates a proton gradient.

Cristae

The folds of the inner mitochondrial membrane that increase the surface area for ATP production.

Oxaloacetate

A four-carbon molecule that combines with acetyl-CoA to initiate the citric acid cycle by forming citrate.

Hydroxyl Ethyl Group

An intermediate formed during the conversion of pyruvate to acetyl-CoA.

Hydrophobic Bonding

Non-polar interactions between hydrophobic molecules, important for enzyme-substrate specificity.

Proton Gradient

A difference in proton concentration across a membrane that drives ATP synthesis.

Succinate Dehydrogenase

An enzyme that catalyzes the conversion of succinate to fumarate while producing FADH2.