FOM week 5 Flashcards
What are the main types of living organisms in infection classification?
Protozoa (single-celled, eukaryotic), Fungi (eukaryotic, plant-like), Bacteria (prokaryotic, single-celled), Viruses (non-living, obligate parasites).
What are the key differences between eukaryotes and prokaryotes?
Eukaryotes: Larger (5-50?m), complex, often multicellular, linear chromosomes, 80S ribosomes. Prokaryotes: Smaller (0.5-10?m), simpler, mostly single-celled, single circular chromosome, 70S ribosomes.
What is the function of the bacterial cytoplasmic membrane?
It generates energy through a proton gradient and is a target for antimicrobial agents like ethanol.
What distinguishes Gram-positive from Gram-negative bacteria?
Gram-positive: Thick peptidoglycan layer, stains purple. Gram-negative: Thinner peptidoglycan layer, stains pink, with an additional outer membrane containing lipopolysaccharide (LPS).
What is Lipopolysaccharide (LPS)?
A component of the outer membrane of Gram-negative bacteria that acts as an endotoxin and influences inflammation and antibiotic uptake.
How do bacteria generate energy?
By using electron transport chains to create proton gradients across their membranes.
What factors affect bacterial growth?
Food (C, O, H, N), temperature (psychrophiles, thermophiles), pH (neutral for human commensals), oxygen requirements (aerobes, anaerobes).
What are biofilms?
Bacterial colonies that adhere to surfaces, often more resistant to antimicrobials and important for survival and virulence.
What is the microbiome?
The community of microorganisms and their genetic material associated with a host.
What are the types of bacterial pathogens?
Gram-negative: Neisseria meningitidis, Escherichia coli, Salmonella. Gram-positive: Streptococcus, Staphylococcus aureus, Enterococcus.
What are the main shapes of bacteria?
Coccus (spherical), Bacillus (rod-shaped), Vibrio (curved rod), Spirillum (rigid spiral), Spirochaete (flexible spiral), Fusiform (spindle-shaped).
What is the role of bacterial capsules and spores?
Capsules: Protective outer polysaccharide layer. Spores: Resistant structures formed in adverse conditions.
What are selective and differential media?
Selective: Promotes growth of specific organisms. Differential: Produces visible changes to identify bacteria.
What are the steps in viral replication?
- Attachment, 2. Entry, 3. Uncoating, 4. Synthesis, 5. Assembly, 6. Release (budding or lysis).
What are cytotoxic T lymphocytes (CTLs)?
Immune cells that target and destroy infected cells.
What are the types of immunoglobulins and their functions?
IgM: First response, agglutination. IgG: Most abundant, neutralizes pathogens. IgA: Mucosal immunity. IgD: B cell activation. IgE: Allergic reactions, parasitic infections.
What is the complement system?
A series of proteins that enhance immune responses by opsonizing pathogens, killing them, or promoting inflammation.
What are the primary immune cells in innate immunity?
Macrophages, mast cells, neutrophils, NK cells, dendritic cells.
What are the pathways of viral entry into the body?
Respiratory tract, gastrointestinal tract, urogenital tract, blood.
What is the difference between latent and chronic viral infections?
Latent: Virus dormant with no active replication (e.g., herpes). Chronic: Ongoing replication and persistence (e.g., HIV).
What are pro-inflammatory cytokines?
Cytokines that enhance immune responses, such as IL-1 and TNF?.
What is sepsis?
An overreaction of the immune system to infection, leading to organ failure and damage.
What is the function of viral envelopes?
A lipid bilayer that surrounds some viruses, aiding in entry and immune evasion.
