Chapter 5 Microbiology

Catabolism

Breaking down complex molecules into simpler ones

Anabolism

Building complex molecules from simpler ones

Metabolism

All chemical reactions that occur within an organism, both catabolic and anabolic reactions

Catalyst

Substance that speeds up chemical reactions

Carbs, lipids, proteins

Three sources of energy for cells

Exergonic

Release energy to the environment. Free energy of reactants is higher than product.

ATP

Main carrier of energy within a cell, hydrolyzed to release energy

NAD+

Important in metabolism, transfers molecules from one molecule to another

Enzyme

Biological catalyst that speeds up chemical reactions without being consumed.

Optimal temperature for an Enzyme

37°C or body temp, extreme temps cause denaturation

Activation energy

The minimum amount of energy required for a chemical reaction to occur, lowered by enzymes

Substrates

Typically acts on a specific substrate or closely related substrates due to the active site's unique shape

Glycolysis

The process where a six-carbon sugar molecule (glucose) is split into two three-carbon molecules (pyruvates), producing two molecules of NADH and a net gain of two molecules of ATP.

Fermentation

A metabolic process occurring in the cytoplasm that follows glycolysis in the absence of oxygen, producing different end products such as ethanol, carbon dioxide, or lactic acid, and regenerating NAD+ from NADH to sustain glycolysis.

Aerobic Respiration

The process taking place in the mitochondria that follows glycolysis in the presence of oxygen, involving pyruvate decarboxylation, the Krebs Cycle, and the Electron Transport Chain to produce carbon dioxide, water, and ATP.

Krebs Cycle

The stage of aerobic respiration where acetyl CoA combines with a four-carbon molecule to undergo a series of reactions, generating two molecules of carbon dioxide, one ATP, three NADH, and one FADH2 per acetyl CoA.

NADH

A molecule carrying high-energy electrons produced during glycolysis and the Krebs Cycle, which plays a crucial role in the Electron Transport Chain to generate ATP.

Electron Transport Chain

A series of protein complexes in the inner mitochondrial membrane where NADH and FADH2 deposit their electrons, leading to the pumping of protons and the synthesis of ATP through oxidative phosphorylation.

Anaerobic Respiration

A process encompassing glycolysis and fermentation that occurs in the absence of oxygen, yielding a total of 2 ATP per glucose molecule and regenerating NAD+ for glycolysis to continue.

Active Site

Where enzymes bind to substrate molecules

Endergonic

Requires energy to proceed, free energy of products is higher than reactants

Oxidation

Involves loss of electrons

Reduction

Involves gain of electrons