Bacterial Metabolism

Comprehensive practice flashcards covering bacterial metabolism, including major carbohydrate, lipid, and amino acid pathways, bioenergetics, and photosynthesis based on lecture notes.

Metabolism

The total of all chemical reactions occurring in the cell, divided into energy-conserving reactions and reactions that consume energy.

Catabolism

The breakdown of relatively large, complex organic molecules like proteins, lipids, and carbohydrates into smaller, simpler molecules to generate energy.

Anabolism

The synthesis of complex organic molecules from simpler ones, such as amino acids and fatty acids, involving reactions that consume energy.

ATP (Adenosine Triphosphate)

A byproduct of catabolism and the primary carrier of energy in living organisms, used for biosynthesis and other metabolic reactions.

Amphibolic Pathways

Pathways that can function both catabolically and anabolically, such as the Embden-Meyerhof-Parnas pathway and the TCA cycle.

Embden-Meyerhof-Parnas (EMP) Pathway

The most common carbohydrate pathway, also known as glycolysis, which converts sugars into pyruvic acid in both microorganisms and humans.

Pentose Phosphate Pathway (PPP)

Also known as the hexose monophosphate shunt, this pathway generates $NADPH$ and 5-carbon sugars like Ribose-5-phosphate for DNA and RNA synthesis.

Entner-Doudoroff Pathway (EDP)

Also known as the Ketogluconate pathway, it is found only in certain prokaryotes, replaces EMP in some organisms, and yields 1 $ATP$ per glucose.

$eta$-oxidation

The process by which fatty acids in the form of acyl-CoA are broken down 2 carbon atoms at a time to generate Acetyl-CoA.

Gluconeogenesis

The reverse of glycolysis; the synthesis of hexoses from poor carbon sources such as succinate, L-malate, acetate, or glycerol when carbohydrates are depleted.

Tricarboxylic Acid (TCA) Cycle

Also known as the Krebs cycle, it oxidizes Acetyl-CoA to $CO_2$ and generates $NADH$ and $FADH_2$ for the electron transport chain.

Fermentation

A microbially mediated anaerobic process where organic molecules serve as both electron donors and acceptors, often resulting in alcohol or ethanol as byproducts.

Lipases

Enzymes that separate lipids into glycerol and fatty acids during catabolism.

Acyl Carrier Protein (ACP)

A small protein involved in the stepwise build-up of long-chain fatty acids 2 carbons at a time during fatty acid synthesis.

Nucleotide

A molecule containing a nitrogenous base, a sugar, and a phosphate group; the building block of DNA.

Nucleoside

A molecule consisting of only a sugar and a nitrogenous base, lacking a phosphate group.

Oxygenic Photosynthesis

The production of energy from light during which oxygen is set free, utilizing linked photosystems I and II as seen in Cyanobacteria.

Anoxygenic Photosynthesis

Photosynthesis observed in bacteria like green or purple bacteria where no oxygen is produced.

Assimilatory Pathways

Inorganic metabolism pathways where inorganic nitrogen and sulfur are incorporated into organic materials.

Dissimilatory Pathways

Pathways where inorganic compounds are used as electron acceptors and the reduced products are excreted into the environment.

Electrochemical Energy

Energy generated by an ion gradient across the cell membrane, used for solute transport, flagella rotation, and $ATP$ synthesis.

Oxidative Phosphorylation

Also known as electron transport phosphorylation, it occurs in the cell membrane and is coupled to redox reactions via an electrochemical gradient.

Substrate Level Phosphorylation

The phosphorylation of $ADP$ in the soluble part of the cell using high energy phosphoryl donors like phosphoenolpyruvate or 1,3-bisphosphoglycerate.

Quinones

A class of lipid electron carriers that shuffle substances between stations in the electron transport chain.

Cytochromes

Electron carriers that contain heme as a prosthetic group where iron is bound to the nitrogen of the pyrrole ring.

Proton Motive Force (PMF)

The energy released by the controlled dissipation of a pH gradient and electrochemical potential used in the synthesis of $ATP$.

Chemiosmotic Theory

The theory that energy-transducing membranes pump protons to generate a gradient that does work when protons return across the membrane.

ATP Synthase (ATPase)

The enzyme that catalyzes $ATP$ synthesis as protons re-enter the cell, undergoing a conformational change during the process.