Aseptic Technique and Cell Biology – Lab Procedures and Chapter 3 Concepts

Vocabulary flashcards covering key lab practices, terminology, and basic cell biology concepts from the lecture notes.

Aseptic technique

A set of practices to prevent microbial contamination of cultures, tubes, and lab surfaces.

Sterile technique

Another term for aseptic technique; procedures that aim to eliminate all life forms from objects or environments.

Sepsis

Spreading of infection within the body, often through the bloodstream.

Inoculate

To introduce a microorganism into a culture medium.

Inoculum

The material containing microorganisms that is added to a culture.

Nutrient media

Media that provide nutrients for microbial growth; commonly includes nutrient broth (NB) and nutrient agar (NA).

Nutrient broth (NB)

A liquid nutrient medium used to grow microorganisms.

Nutrient agar (NA)

A solid nutrient medium formed with agar to culture microorganisms; agar acts as a solidifying agent.

Broth

A liquid medium used for growing microorganisms.

Agar

A solidifying agent used to make solid media; not itself a nutrient.

Incubate

To grow microorganisms under controlled environmental conditions, especially temperature.

Incubator

A device that maintains a controlled temperature (and sometimes CO2) for growing cultures.

Serratia marcescens

A bacterium used in labs that often produces a red pigment; used to make results more interesting.

Loop

A curved wire tool used to transfer bacteria and streak plates; sterilized between uses.

Needle

A straight needle used to inoculate agar by stabbing; used for deep inoculations.

Incinerator

A flame-based device used to sterilize metal instruments by burning; only the wire part should be inserted.

Sterilize

To kill all living organisms; achieve complete absence of life.

Disinfect

To kill or remove many microorganisms on surfaces; does not always achieve sterility.

Disinfectant BioClean

A pH-neutral disinfectant used on lab benches; requires about ten minutes of contact time.

Goggles

Safety eyeglasses worn to protect eyes during lab work; located in a designated room.

45-degree angle (opening tubes)

Angle used when opening test tubes to minimize contamination from dust landing inside.

Mouth closed when opening a tube

Keep the tube’s opening closed when not actively transferring to prevent contamination.

Lid handling (test tubes)

Keep lids on and avoid setting them on the bench to prevent contamination.

NB and NA abbreviations

NB stands for nutrient broth (liquid); NA stands for nutrient agar (solid medium).

Incubation at 25°C

Room-temp incubation used for some cultures; boxes are labeled with temperature and schedule.

Streaking

Inoculation technique to spread a culture on a surface of agar to obtain isolated colonies.

Stab inoculation

Inoculation technique using a needle to inoculate the interior of an agar stab (deep).

Tape labeling

Label tubes with tape (name and organism) rather than writing on glass; easier to remove and dispose.

Vortex

A mixer used to homogenize liquid cultures; vortex cultures before inoculation when needed.

Culture

A growth of microorganisms in or on a suitable medium.

Membrane (cell membrane)

The phospholipid bilayer that separates the inside of the cell from the outside environment.

Phospholipid head and tail

Head is hydrophilic (water-loving); tails are hydrophobic (water-fearing).

Cholesterol in bacterial membranes

Bacteria do not use cholesterol in their membranes.

Integral vs peripheral proteins

Integral proteins span the membrane; peripheral proteins are attached to the surface or membrane.

Transport proteins

Proteins that aid substances in crossing the cell membrane (channels and carriers).

Selective permeability

The membrane allows some substances to pass while restricting others.

Diffusion

Movement of molecules from high to low concentration without energy input.

Facilitated diffusion

Diffusion that requires help from transport proteins to cross the membrane.

Osmosis

Diffusion of water across a membrane; may occur directly or via aquaporins.

Surface area to volume ratio

Smaller cells have a larger surface area relative to volume, enabling faster exchange with the environment.

Cocci

Spherical bacteria; include arrangements like diplo-, strepto-, and staphylo-.

Bacilli

Rod-shaped bacteria; can occur singly or in various arrangements.

Streptococcus

A chain-forming arrangement of cocci (strepto- means chain).

Staphylococcus

A cluster-forming arrangement of cocci (staphylo- means cluster).

Spirochete

A spiral-shaped bacterium (corkscrew-like).

Vibrio

A curved rod-shaped bacterium (comma-shaped).