Microbiology Exam 2 Study Guide - Spring 2022

Essential Nutrients: Substances that organisms must obtain from their environment to survive and grow.
Macronutrients: Nutrients required in large amounts.
Micronutrients: Nutrients needed in smaller amounts, but still essential for growth.
Six Essential Macronutrients:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
- Nitrogen (N)
- Phosphorus (P)
- Sulfur (S)
Six Micronutrients:
- Potassium (K)
- Sodium (Na)
- Calcium (Ca)
- Magnesium (Mg)
- Iron (Fe)
- Zinc (Zn)
Heterotroph: Organisms that obtain carbon from organic compounds.
Autotroph: Organisms that obtain carbon from inorganic sources, such as carbon dioxide.
Phototroph: Organisms that use light energy to synthesize compounds.
Chemotroph: Organisms that obtain energy from chemical compounds.
Saprobe: Organisms that obtain nutrients from decaying organic matter.
Parasite: Organisms that live on or in another organism and derive nutrients at the host's expense. (Examples include tapeworms, lice)

Passive Transport: Movement across cell membranes without energy input.
- Diffusion: Movement of particles from an area of higher concentration to lower concentration.
- Osmosis: Diffusion of water through a selectively permeable membrane.
Active Transport: Movement against the concentration gradient requiring energy (ATP).
Endocytosis: Process by which cells engulf external material.
- Pinocytosis: Cell engulfs liquid.
- Phagocytosis: Cell engulfs large particles or cells.

Temperature Range: Organisms classified by their temperature preferences (psychrophiles, mesophiles, thermophiles).
Oxygen Usage and Tolerance: Varies among microorganisms, resulting in classifications such as obligate aerobes, facultative anaerobes, and obligate anaerobes.

Symbiosis: Interaction between different biological species. It includes:
- Mutualism: Both parties benefit.
- Commensalism: One benefits, while the other is neither helped nor harmed.
- Parasitism: One benefits at the expense of the other.
Antagonism: The relationship where one organism produces substances harmful to another.
Synergism: Interactions that produce a result greater than the sum of individual effects.
Biofilms: Complex communities of microorganisms that adhere to surfaces and are encased in a protective matrix.

Growth Curves: Sequential changes in microbial population levels over time, typically characterized by the lag phase, log phase, stationary phase, and death phase.

Anabolism: Biosynthetic processes that build complex molecules from simpler ones, requiring energy.
Catabolism: Breakdown of complex molecules into simpler ones, releasing energy.
Enzymes: Biological catalysts that increase the rate of reactions without being consumed.
- Structure: Composed of proteins, may have a cofactor (non-protein) or coenzyme (organic cofactor).
Constitutive Enzymes: Present at all times regardless of conditions.
Regulated Enzymes: Synthesis or activity modified in response to environmental changes, including induction and repression.
Denaturation: Loss of 3D structure of proteins, resulting in loss of function, often due to extreme temperature or pH changes.
Types of Inhibition:
- Competitive Inhibition: Inhibitor competes with the substrate for the active site.
- Non-competitive Inhibition: Inhibitor binds to an allosteric site, altering enzyme function.
Exergonic vs. Endergonic Reactions:
- Exergonic: Reactions that release energy.
- Endergonic: Reactions that require energy input to proceed.
Redox Reactions: Chemical reactions involving the transfer of electrons between substances.
- Reduced Substance: Gains electrons and its charge becomes more negative (i.e., its charge is reduced).
- Oxidized Substance: Loses electrons and its charge becomes more positive (opposite of reduction).