micro exam 2

Sterilization

The process of completely destroying all forms of microbial life, including bacterial endospores.

Disinfection

The process of reducing the number of microorganisms on inanimate objects to a level that is considered safe.

Decontamination

Also known as sanitization, it is the process of reducing the number of microorganisms on inanimate objects to a level that is considered safe.

Antisepsis

Also known as degermation, it is the process of applying chemical agents directly to exposed body surfaces to prevent the growth of vegetative pathogens.

Microbicidal agents

Chemical agents that kill microorganisms.

Microbistatic agents

Chemical agents that prevent the growth of microorganisms.

Bacterial endospores

Highly resistant forms of bacteria that can survive harsh conditions.

Cellular targets

Specific components of microorganisms that physical and chemical agents can act upon to control their growth.

Sepsis

The growth of microorganisms in the blood and other tissues.

Asepsis

Practices that prevent the entry of infectious agents into sterile tissues to prevent infection.

Antiseptics

Chemical agents applied directly to exposed body surfaces, wounds, and surgical incisions to prevent the growth of vegetative pathogens.

Bacteristatic

Chemical agents that prevent the growth of bacteria on tissues or objects in the environment.

Fungistatic

Chemicals that inhibit fungal growth.

Microbial death

The permanent termination of an organism's vital processes.

Death rate

The rate at which microorganisms are killed by a microbicidal agent.

Cellular targets of physical and chemical agents

The specific components of microorganisms that physical and chemical agents target to kill or inhibit their growth.

Moist heat

The use of hot water, boiling water, or steam to control microorganisms.

Dry heat

The use of hot air or an open flame to control microorganisms.

Thermal death time

The shortest length of time required to kill all test microbes at a specified temperature.

Thermal death point

The lowest temperature required to kill all microbes in a sample in 10 minutes.

Filtration

The process of passing a liquid or gas through a filter to remove microorganisms.

Osmotic pressure

The use of high concentrations of salt or sugar to control microorganisms.

Incineration

The process of burning microorganisms to ashes using high temperatures.

Hot air oven

The use of hot air to control microorganisms.

Cold treatment

The use of low temperatures to slow the growth of microorganisms.

Desiccation

The process of drying out microorganisms.

Lyophilization

The process of freeze-drying microorganisms.

Lyophilization

A method of preserving microorganisms by freezing and drying them, allowing them to remain viable for many years.

Radiation

Energy emitted from atomic activities and dispersed at high velocity through matter or space.

Ionizing Radiation

Gamma rays and X rays, which have the ability to ionize atoms and molecules.

Nonionizing Radiation

Ultraviolet rays, which do not have the ability to ionize atoms and molecules.

Filtration

An effective method to remove microbes from air and liquids by passing them through a filter with controlled pore sizes.

Osmotic Pressure

Adding large amounts of salt or sugar to create a hypertonic environment that causes plasmolysis in bacteria.

Chemical Agents in Microbial Control

Substances that range from disinfectants and antiseptics to sterilants and preservatives.

Desirable Qualities in a Germicide

Rapid action, solubility, broad-spectrum microbicidal action, penetration, resistance to inactivation, non-corrosive, and affordable.

High-, Intermediate-, and Low-Level Germicides

Germicides evaluated based on their effectiveness in destroying different types of microbes.

Factors Affecting the Germicidal Activity of Chemicals

Nature of microorganisms, nature of material being treated, degree of contamination, time of exposure, and strength and chemical action of the germicide.

Required Concentrations and Times for Chemical Destruction of Selected Microbes

Different concentrations and exposure times needed to effectively destroy specific microbes.

Metabolism

Pertains to all chemical reactions and physical workings of the cell.

Anabolism

Any process that results in synthesis of cell molecules and structures.

Catabolism

Breaks the bonds of larger molecules into smaller molecules and releases energy.

Enzymes

Biological catalysts that increase the rate of chemical reactions.

Enzyme characteristics

Made of protein, act as organic catalysts, have unique characteristics such as shape, specificity, and function.

Enzyme structure

Simple enzymes consist of protein alone, conjugated enzymes contain protein and nonprotein molecules.

Enzyme-substrate interactions

Temporary union between enzyme and substrate at the active site.

Cofactors

Organic molecules called coenzymes or inorganic elements that participate in enzyme-substrate interactions.

Coenzymes

Organic compounds that work in conjunction with an apoenzyme to carry and transfer chemical groups.

Enzyme naming

Enzymes are classified and named based on characteristics such as site of action, type of action, and substrate.

Regulation of enzyme action

Enzyme activity can be influenced by temperature, pH, and other factors.

Denaturation

Weak bonds that maintain the native shape of the enzyme are broken, causing distortion of the enzyme's shape.

Competitive inhibition

Inhibits enzyme activity by supplying a molecule that resembles the enzyme's normal substrate.

Noncompetitive inhibition

Enzymes have two binding sites, the active site and a regulatory site, and molecules bind to the regulatory site to slow down enzymatic activity.

Enzyme repression

Genetic apparatus responsible for replacing enzymes is automatically suppressed.

Enzyme induction

Enzymes appear only when suitable substrates are present.

Metabolic pathways

Multistep series or pathway of reactions catalyzed by enzymes.

Energy in cells

Mostly stored as ATP and managed through chemical reactions involving the making and breaking of bonds and the transfer of electrons.

Oxidation and reduction

Oxidation is the loss of electrons, reduction is the gain of electrons.

Redox reactions

Enzymes called oxidoreductases remove electrons from one substrate and add them to another.

NAD and FAD

Coenzyme carriers involved in redox reactions.

ATP

Three-part molecule that stores and releases energy for cellular work.

ATP utilization and replenishment

Energy released during ATP hydrolysis drives biosynthesis and prepares molecules for catabolism.

Heterotrophs

Organisms that obtain energy by consuming organic matter from other organisms.

Catabolic pathways

Metabolic pathways that break down organic molecules to release energy.

ATP

Adenosine triphosphate, a molecule that stores and releases energy for cellular processes.

ADP

Adenosine diphosphate, a molecule that is converted to ATP by adding a phosphate group.

Glycolysis

The metabolic pathway that converts glucose into pyruvic acid, producing a small amount of ATP.

Krebs cycle

Also known as the citric acid cycle, a series of reactions that generates energy-rich molecules (NADH and FADH2) and ATP.

Electron transport system

A series of redox reactions that transfer electrons from NADH and FADH2 to generate ATP.

Anaerobic respiration

The process of generating energy without the use of oxygen as the final electron acceptor.

Aerobic respiration

The process of generating energy using oxygen as the final electron acceptor.

Fermentation

The process of converting glucose into ethanol or lactic acid in the absence of oxygen.

Noncarbohydrate compounds

Organic molecules other than carbohydrates that can be catabolized for energy.

Metabolism

The sum of all chemical reactions that occur in an organism.

Anabolism

The process of building larger, more complex molecules from smaller precursor molecules.

Amphibolism

The integration of catabolic and anabolic pathways to improve cell efficiency.

Monosaccharides

Simple sugars that are the building blocks of carbohydrates.

Amino acids

The building blocks of proteins.

Fatty acids

The building blocks of lipids.

Nitrogen bases

The building blocks of nucleic acids.

Carbohydrate biosynthesis

The process of synthesizing carbohydrates from simpler molecules.

Protein synthesis

The process of building proteins from amino acids.

Nucleic acid synthesis

The process of building DNA and RNA from nucleotides.

Cell division

The process of a cell dividing into two daughter cells.

Genome

The sum total of genetic material of an organism.

Gene

A segment of DNA that codes for a specific protein or RNA molecule.

Genotype

The sum of all gene types; an organism's distinctive genetic makeup.

Phenotype

The expression of certain traits (structures or functions) in an organism.

Nucleotide

The basic unit of DNA structure, consisting of a phosphate, deoxyribose sugar, and a nitrogenous base.

Chromosome

A distinct cellular structure composed of a neatly packaged DNA molecule.

DNA Replication

The process by which DNA is copied to produce two identical daughter molecules.

Leading Strand

The strand of DNA that is synthesized continuously during DNA replication.

Lagging Strand

The strand of DNA that is synthesized discontinuously during DNA replication.

Double Helix

The twisted ladder-like structure of DNA, consisting of two antiparallel strands.

DNA Polymerase

The enzyme responsible for synthesizing new DNA strands during replication.

Transcription

The process by which the DNA code is used to synthesize an RNA molecule.

Translation

The process by which the transcribed RNA is used to produce a protein.

Codon

A group of three nucleotides that dictates which amino acid is added to the growing peptide chain during translation.

Anticodon

A sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on mRNA.

Operon

A coordinated set of genes regulated as a single unit in bacteria and archaea.

Lac Operon

An operon involved in the regulation of lactose metabolism in bacteria.