Microbial Growth & Culturing, Metabolism & Enzyme Kinetics, and Biotechnology & Molecular Techniques

These flashcards cover key concepts related to microbial growth, metabolism, enzyme kinetics, and biotechnological applications.

Lag Phase

The initial phase of bacterial growth where cells adapt to new media and 're-stock' metabolites.

Log (Exponential) Phase

The phase of maximum growth rate in bacterial growth; cells are at their healthiest.

Stationary Phase

The phase where growth slows as nutrients are exhausted and waste products accumulate.

Death Phase

The phase where nutrients are no longer available and toxic waste levels result in cell lysis.

Optical Density (OD)

A measurement using a spectrophotometer to assess light scattering; counts both living and dead cells.

Viable Count (CFU)

A method involving dilution and plating samples to count only the living (colony-forming) cells.

Batch Culture

A closed system in microbiology where no nutrients are added and no waste is removed, leading to changing growth conditions.

Continuous Culture (Chemostat)

An open system in microbiology where nutrients are constantly replenished and waste is removed.

Selective Media

Medium that encourages the growth of specific organisms while suppressing others.

Differential Media

Medium that contains constituents causing observable changes to help distinguish between species.

Anabolism

The metabolic pathway that consumes energy to build complex molecules from simpler ones.

Catabolism

The metabolic pathway that releases energy by breaking down complex molecules into simpler ones.

Glycolysis

The first stage of aerobic cellular respiration, converting 1 glucose into 2 pyruvate, producing 2 ATP and 2 NADH.

Citric Acid Cycle (Krebs Cycle)

The stage of aerobic respiration where acetyl groups are oxidized to CO2, producing ATP, NADH, and FADH2.

Oxidative Phosphorylation

The final stage of aerobic respiration utilizing the electron transport chain to produce approximately 26–28 ATP.

Michaelis Constant (Km)

The substrate concentration at which the reaction rate is half of Vmax; reflects the stability of the enzyme-substrate complex.

Competitive Inhibitor

An inhibitor that binds to the active site of an enzyme, increasing Km while Vmax remains unchanged.

Non-competitive Inhibitor

An inhibitor that binds to an allosteric site on the enzyme, decreasing Vmax while Km remains unchanged.

PCR

Polymerase Chain Reaction, a technique for amplifying DNA that involves denaturation, annealing, and extension.

Taq Polymerase

A heat-stable enzyme from Thermus aquaticus used in PCR to withstand high temperatures.

Recombinant DNA

DNA formed by combining DNA from different sources, used to produce human insulin.

CRISPR-Cas9

A gene-editing system that acts like 'find and replace' for DNA, originating from bacteria.

Bacteriostatic Antibiotics

Antibiotics that inhibit the growth of bacteria.

Bactericidal Antibiotics

Antibiotics that kill bacterial cells.

Bacteriolytic Antibiotics

Antibiotics that kill bacteria by causing cell lysis.