Introduction To Microbiology Flashcards
(28 cards)
What are mesosomes?
Large invaginations of the plasma membrane, irregular in shape
They increase membrane surface, potentially useful for enzyme activity in respiration and transport, and may participate in cell replication.
What is the shape of vibrio bacteria?
Comma-shaped or curved
This morphology is one of the classifications of bacterial shapes.
What is the morphology of cocci bacteria?
Spherical or nearly spherical
Cocci can exist in various arrangements such as diplococci, tetrads, sarcina, streptococci, and staphylococci.
What are diplococci?
Coccus pairs
An example of diplococci is Neisseria.
What are tetrads in bacterial arrangements?
Groups of four or eight cocci
An example of tetrads is Micrococci.
What are streptococci?
Bead-like chains of cocci
An example of streptococci is Streptococcus.
What are staphylococci?
Grape-like clusters of cocci
This arrangement is typical in certain bacterial infections.
What is the classification of bacteria based on?
Morphology, Gram reaction, Oxygen requirement
These criteria help in identifying and categorizing bacteria.
What type of cellular configuration do bacteria have?
Prokaryotic
The genetic material exists unbound in the cytoplasm.
What is the size range of bacteria?
0.1 µm to 10 µm
This small size allows them to thrive in various environments.
What defines a parasite?
An organism that lives on or in another and uses that organism for nourishment
Infections caused by parasites are referred to as infestations.
What are the two main groups of fungi?
Yeasts and molds
Yeasts are single-celled fungi, while molds are multicellular.
What are the steps in diagnosing infections?
- Examine patient signs and symptoms
- Obtain specimens
- Examine specimens directly
- Culture the specimen
- Determine culture’s antibiotic sensitivity
- Treat the patient as ordered
These steps are crucial for accurate diagnosis and treatment.
What does the Gram stain classify bacteria into?
Gram positive and Gram negative
This classification is based on the structure of the bacterial cell wall.
What are the oxygen requirements for bacteria?
Aerobic, facultative aerobic, anaerobic
These categories determine how bacteria metabolize oxygen.
What are the surface layers of bacterial cell structure?
Capsule, cell wall, cell membrane
These layers protect the cell and assist in its functions.
What is the function of the bacterial cell membrane?
Control permeability, transport electrolytes and proteins, contain enzymes for metabolism, secrete hydrolytic enzymes, regulate cell division
These functions are essential for bacterial survival and reproduction.
What characterizes Gram positive bacterial cell walls?
Thick peptidoglycan layer, pentaglycin cross linkage, teichoic acid
Gram positive bacteria retain the crystal violet stain used in Gram staining.
What is unique about Gram negative bacterial cell walls?
Thin peptidoglycan layer, second membrane structure with protein and lipopolysaccharide
The lipopolysaccharide contains lipid A, which is toxic.
What are endospores?
Special structures formed by some bacteria that are extremely resistant to harsh conditions
They can survive heat, UV light, and chemicals.
What is the primary function of flagella?
Motility
Flagella enable bacteria to move towards favorable environments.
What is the composition of the bacterial cytoplasm?
80% water, nucleic acids, proteins, carbohydrates, lipids, inorganic ions
This composition is vital for cellular functions.
What is the significance of ribosomes in bacteria?
Site of protein synthesis
Bacterial ribosomes are 70S in size.
What are the differences between prokaryotic and eukaryotic cells?
Prokaryotes lack a nucleus and organelles, while eukaryotes have a defined nucleus and multiple organelles
This distinction is fundamental in microbiology.
