Mircobio #2

Bacteria

Prokaryotic cells that are generally very small (0.2-2.0 micrometers) without a nuclear membrane.

Prokaryotic cells

Cells that lack a true nucleus and membrane-bound organelles, characterized by their simple structure.

Eukaryotic cells

Cells that have a true nucleus and membrane-bound organelles, including fungi, plant cells, protozoa, and metazoa.

Binary fission

The method of cell division in prokaryotic cells.

Capsule

A protective layer in some bacteria that aids in survival and evading the immune system.

Nucleotide

The area in prokaryotic cells containing chromosomal DNA, without a surrounding membrane.

Plasma membrane

A phospholipid bilayer that performs various functions, including synthesis, secretion, and energy production.

Ribosomes

Cellular structures involved in protein synthesis, typically consisting of 70s subunits in prokaryotes.

Peptidoglycan

A structural component of bacterial cell walls primarily providing rigidity.

Gram-positive bacteria

Bacteria that retain the crystal violet stain used in Gram staining, characterized by thicker peptidoglycan layers.

Gram-negative bacteria

Bacteria that do not retain the crystal violet stain and have an outer membrane containing lipopolysaccharides.

Chromosomal DNA

The main genetic material in bacteria, usually a single circular strand located in the nucleotide.

Extrachromosomal DNA

Primary examples being plasmids, which provide selective advantages such as antibiotic resistance.

Flagella

Hair-like structures that aid in the mobility of bacteria by propelling them through their environment.

Fimbrae

Short, hair-like structures that promote adherence of bacteria to surfaces or other cells.

Sexual reproduction in bacteria

Not present in prokaryotic cells, which reproduce asexually.

Simple flagella

The less complex form of flagella found in prokaryotic cells.

Complex flagella

More intricate flagella found in eukaryotic cells, allowing for more versatile movement.

Gram staining

A critical technique used to classify bacteria based on their cell wall composition.

Acid-fast stain

A staining method specifically used to identify mycobacterial organisms, such as those causing tuberculosis.

Antiphagocytic

Refers to the ability of certain bacterial structures like capsules to evade phagocytosis by immune cells.

Morphological classification of bacteria

Classification method based on the shape of bacterial cells, such as cocci, bacilli, or spirilla.

Aerobic bacteria

Bacteria that require oxygen for growth.

Anaerobic bacteria

Bacteria that do not require oxygen for growth and may even be harmed by it.

Facultative anaerobes

Bacteria that can grow in both the presence and absence of oxygen.

Serotyping

A method to classify bacteria based on their antigens using antibodies.

Coccus

A spherical-shaped bacteria.

Bacillus

A rod-shaped bacteria.

Spirillum

A spiral-shaped bacteria.

Gram stain steps

The four key steps involved in performing a Gram stain: 1) Apply Crystal Violet, 2) Add Iodine, 3) Decolorize with alcohol, 4) Apply counterstain.

Teichoic acids

Components found in Gram-positive bacteria that are important for their structural integrity.

LPS (Lipopolysaccharides)

A component of the outer membrane of Gram-negative bacteria that can trigger strong immune responses.

Mycobacteria

Bacteria characterized by a different peptidoglycan structure and a lipid coat of mycolic acid, leading to acid-fastness.

Capsule function

Aids in the adherence to surfaces and protection against the host immune response.

Cytoplasm

The gel-like substance within the bacterial cell where various cellular processes occur.

Inclusions

Storage bodies in bacterial cells that contain nutrients.

Ribosome function

The site of protein synthesis in the cell.

Cytoskeleton in prokaryotes

Absent in prokaryotic cells, unlike eukaryotic cells which possess a complex cytoskeleton.

Genus and species naming

The two-part naming convention for bacteria where the genus is capitalized and species is lowercase, both italicized.

Bacterial cell wall

A complex structure that provides shape and protection, composed of peptidoglycan in many bacteria.

Mycoplasmas

A type of bacteria that lack a cell wall, making them resistant to certain antibiotics.

Energy production in bacteria

Occurs in the plasma membrane, as bacteria do not have mitochondria.

Nutritional requirements for bacteria

Bacteria have varying needs for nutrients which can categorize them further.

Antigenic properties of bacteria

Characteristics that allow the immune system to recognize bacterial cells.

Bacterial survival in hosts

Some bacteria possess features such as capsules that enhance their survival against host defenses.

Protein synthesis in bacteria

Occurs on ribosomes where mRNA is translated into proteins.

Two names convention for bacteria

Refers to the system of nomenclature in which every bacterial species is identified by a combination of its genus and species names.

Bacterial morphology

The study of the physical form and structure of bacteria.

Role of flagella

Facilitates movement towards nutrients and away from toxins.

Gram stain importance

Essential for diagnosing bacterial infections and determining treatment options.

Plasma membrane composition

Contains a phospholipid bilayer along with proteins, sterols, and carbohydrates.

Role of enzymes in bacteria

Synthesis and secretion of various enzymes and toxins are crucial for bacterial survival and pathogenicity.

Chemical composition differences

The bacterial plasma membrane differs from human and fungal cell membranes in sterol presence.