BACTERIOLOGY & INFECTION CONTROL Flashcards
(34 cards)
What is the definition of Bacteriology?
Bacteriology is the study of bacteria, including their structure, classification, growth, and role in diseases.
What are the three essential components of a bacterial cell?
- Bacterial genome (chromosome and genetic materials)
- Cytoplasm
- Cell wall
What are some non-essential components found in bacteria?
- Capsules
- Flagella
- Pili
- Endospores
What characterizes bacteria as prokaryotic organisms?
Bacteria are characterized by a simple internal structure without a true nucleus or membrane-bound organelles.
What is the function of the bacterial cell wall?
The cell wall provides structural support and shape to the cell, protects against mechanical damage, and prevents osmotic lysis.
What are the two main types of bacterial cell walls?
- Gram-Positive
- Gram-Negative
What is the primary characteristic of Gram-Positive bacteria?
They have a thick peptidoglycan layer and stain purple in Gram staining.
What is a key characteristic of Gram-Negative bacteria?
They have a thin peptidoglycan layer and stain pink in Gram staining.
What distinguishes Acid-Fast bacteria?
They contain mycolic acids and are resistant to antibiotics and desiccation.
What is unique about Mycoplasma bacteria?
They lack a peptidoglycan wall and have no defined shape.
What is the role of the cytoplasm in bacterial cells?
The cytoplasm is the site for cell growth, metabolism, and replication.
What is a nucleoid?
An irregularly-shaped region in the cytoplasm that contains the bacterial chromosome, a single circular DNA molecule.
What are plasmids?
Small, circular, double-stranded DNA molecules independent of the chromosomal DNA that often carry advantageous genes.
What is the size of bacterial ribosomes?
Bacterial ribosomes are 70S in size, consisting of 50S and 30S subunits.
What is the function of flagella in bacteria?
Flagella enable motility and aid in movement toward favorable environments.
What are pili (fimbriae) used for in bacteria?
Pili facilitate attachment to surfaces, host tissues, and other bacteria.
What is the function of a bacterial capsule (glycocalyx)?
The capsule offers protection against environmental hazards and aids in adherence to surfaces.
What are the four main temperature categories for bacterial growth?
- Psychrophiles
- Mesophiles
- Thermophiles
- Hyperthermophiles
What is the optimal pH range for most bacteria?
A neutral pH range of 6.5 to 7.5.
What are obligate aerobes?
Bacteria that require oxygen for growth.
What are facultative anaerobes?
Bacteria that can grow in both the presence and absence of oxygen but prefer oxygen-rich environments.
What nutrients do bacteria require for growth?
- Carbon
- Nitrogen
- Minerals and trace elements
- Vitamins and growth factors
- Water
What is the role of moisture in bacterial growth?
Moisture is crucial for survival and serves as a solvent for cellular reactions.
What are the phases of bacterial growth?
- Lag phase
- Log phase
- Stationary phase
- Death phase
