METABOLISM EXAM REVIEW

Redox

An electron transfer reaction.

Coupled Reaction

A type of reaction in which two reactant molecules are bonded together.

Endergonic

A chemical reaction that absorbs free energy; the products have more free energy than the reactants.

Exergonic

A chemical reaction that releases free energy; the products have less free energy than the reactants.

Isomerase

The enzyme that converts DHAP to G3P in glycolysis.

Isomers

Molecules that have the same composition as another but a different arrangement of atoms.

Phosphorylated

The transfer of a phosphate group, usually from ATP to another molecule.

SLP

The formation of ATP by the direct transfer of a phosphate group from a substrate to ADP.

Chemiosmosis

A way to make ATP; involves a proton pump and a gradient across a membrane.

Dehydrogenase

An enzyme that catalyzes the removal of hydrogen atoms from a substrate.

Decarboxylation

A chemical reaction that removes a carboxyl group to form CO2.

CoA

A molecule that shuttles to the citric acid cycle (CAC).

Impermeable

Cannot pass through the membrane.

Aerobic

Organisms or processes that require oxygen.

Anaerobic

Organisms that can live without oxygen (e.g., yeast).

Facultative Anaerobe

Organisms that can do either aerobic or anaerobic processes (e.g., muscle cells).

Glycolysis

The metabolic pathway that converts glucose to pyruvate; occurs in the cytoplasm.

ETC

Electron Transport Chain; converts O2 to H2O and makes 32 ATP in the cristae of mitochondria.

CAC

Citric Acid Cycle; occurs in the matrix and generates NADH and FADH from acetyl-CoA.

Lactic Acid Fermentation

Anaerobic process occurring in muscle cells; converts pyruvate to lactate.

Ethanol Fermentation

Anaerobic process occurring in yeast; converts pyruvate to ethanol.

Endosymbiotic Theory

The theory that mitochondria and chloroplasts were once free-living bacteria.

Evidence for Endosymbiotic Theory

Mitochondria and chloroplasts are the same size as bacteria, possess circular DNA, and have double membranes.

Isomers in Glycolysis

Includes glucose 6-phosphate/fructose 6-phosphate and DHAP/G3P.

Glycolysis Products

2 pyruvate, 2 H2O, 2 ATP, and 2 NADH.

ATP in Glycolysis

Made by substrate-level phosphorylation (SLP) reactions.

Recycled Molecule in CAC

Oxaloacetate is the recycled molecule.

CAC Products per Glucose

8 NADH, 6 CO2, 2 FADH, and 2 ATP.

Oxidation of Pyruvate

Involves decarboxylation, NADH formation, and conversion to Acetyl-CoA.

NADH Purpose

Generates energy and carries electrons to the transport chain.

FADH Purpose

Serves a similar function to NADH in energy production.

ETC Location

Occurs in the cristae of the mitochondria.

Roles of ETC

Electron transport and Proton pumping.

ATP in ETC

ATP is produced through oxidative phosphorylation.

ETC Products

12 H2O and 32 ATP.

Final Electron Acceptor

Oxygen is the final electron acceptor in the ETC.

ETC Disruption

Cyanide can disrupt the electron transport chain.

Fermentation Purpose

To regenerate NAD+ to keep glycolysis going when O2 is not present.

Fermentation Products

Ethanol and NAD+ from fermentation; lactate and NAD+ from lactic acid fermentation.