Week 3 Microbiology Lab and Immunity Vocabulary

Vocabulary flashcards covering lab safety, bacterial morphology, microscopy, immune system concepts, and common bacteria mentioned in Week 3 notes.

Risk group 1 bacteria

Bacteria considered low risk to healthy people; used in teaching labs with standard safety measures.

Contamination

Unwanted transfer of bacteria into a specimen or environment, potentially affecting results or outcomes.

PPE (Personal Protective Equipment)

Protective gear (gloves, lab coat, eye protection) used to minimize exposure to hazards.

Hair tied up

Safety rule to keep long hair away from faces and flames when working with Bunsen burners.

Bunsen burner

Gas-powered flame tool used to heat substances in the lab; requires safe operation.

Heat fixing

Passing a smear briefly through flame to fix bacteria to a slide and kill them.

Simple stain

One-dye staining method used to visualize bacteria and assess shape (morphology).

Morphology

The shape and arrangement of bacteria (e.g., cocci, bacilli, spirilla).

Cocci

Round, spherical bacteria.

Bacilli

Rod-shaped bacteria.

Spirilla

Spiral-shaped bacteria (includes vibrios and spirochetes).

Diplococci

Two cocci joined together in pairs.

Streptococci

Cocci arranged in chains.

Staphylococci

Cocci arranged in grape-like clusters.

Tetrad

Group of four cocci.

Sarcina

Cube-like arrangement of eight cocci (two tetrads).

Escherichia coli (E. coli)

Rod-shaped, Gram-negative bacterium; common gut inhabitant; used as a lab example.

Bacillus subtilis

Rod-shaped, Gram-positive bacterium used in demonstrations.

Staphylococcus epidermidis

Cocci on human skin; common skin flora; lab example.

Streptococcus pneumoniae

Diplococcus that causes pneumonia; example of a pathogenic Streptococcus.

Clostridium tetani

Bacterium that causes tetanus; anaerobic rod.

Clostridium botulinum

Bacterium that produces botulinum toxin; causes botulism.

Treponema pallidum

Spirochete that causes syphilis.

Vibrio cholerae

Curved rod bacterium that causes cholera; linked to contaminated water.

Salmonella Typhi

Bacterium causing typhoid fever; transmitted via contaminated water/food.

Helicobacter pylori

Bacterium linked to stomach ulcers; discovered by Barry Marshall and Robin Warren.

Streptobacillus

Rod-shaped bacteria arranged in chains; associated with rat bite fever.

Leptospira interrogans

Spirochete causing leptospirosis; slender spiral bacterium.

Pasteurization

Heating milk to kill bacteria and reduce illness from raw milk.

Antibiotic resistance

Bacteria evolve to survive antibiotic exposure; can spread to future generations; major global issue.

Prion

Infectious misfolded protein fragment causing diseases like Creutzfeldt-Jakob; not living.

Trisomy

Having three copies of a chromosome in a cell; examples include Down syndrome (21), Edwards (18), Patau (13).

Down syndrome (Trisomy 21)

Extra copy of chromosome 21; associated with developmental differences.

Edwards syndrome (Trisomy 18)

Extra copy of chromosome 18; associated with multiple anomalies.

Patau syndrome (Trisomy 13)

Extra copy of chromosome 13; associated with severe congenital anomalies.

Algal bloom

Rapid growth of algae due to excess nutrients; can be toxic and affect aquatic life and humans.

Vector

An organism that transmits pathogens between hosts (e.g., fleas, ticks).

Immersion oil

Optical oil used with a 100x objective to improve image resolution; must be cleaned after use.

100x objective

High-power objective lens used with immersion oil to achieve up to 1000x magnification.

Colony

Visible cluster of bacteria growing on agar, derived from a single cell.

Streak plate

Technique for spreading a sample on agar to obtain isolated colonies.

Gram stain

Differential stain distinguishing Gram-positive (purple) from Gram-negative (pink) bacteria.

Mucous membranes

Innate defense barriers lining the nose, mouth, and digestive tract to trap pathogens.

Natural killer cells

Innate immune cells that destroy infected or abnormal cells without prior exposure.

Macrophage

Phagocytic immune cell that engulfs pathogens and presents antigens to T cells; derived from monocytes.

Helper T cell

CD4+ adaptive immune cell that coordinates immune responses after antigen presentation.

Lysosome

Cell organelle containing digestive enzymes used to break down ingested material.

Eosinophil

White blood cell with lysosome-rich granules; combats parasites and participates in allergies.

Innate vs Adaptive immunity

Innate: non-specific, immediate defense; Adaptive: specific, memory-based defense developed after exposure.

Generation time

Average time for a bacterial population to double (often around 12 hours for some bacteria).