Untitled Flashcards Set

Prokaryotes do NOT have __________.

A nucleus

Which of these is NOT a domain of prokaryotes?

has a nucleus

Archaea are considered __________.

Nonpathogenic

What is the main function of bacterial flagella?

Movement

A bacterium with a single flagellum is called __________.

Monotrichous

Bacteria with flagella at both ends are called __________.

Amphitrichous

A bacterium with flagella all over the cell is called __________.

Peritrichous

When a bacterium moves toward a chemical attractant, this is called __________.

Positive chemotaxis

When a bacterium moves away from a harmful substance, this is called __________.

Negative chemotaxis

What is phototaxis?

Movement in response to light

What is halotaxis?

Movement in response to salt

Which of these bacterial shapes does NOT typically have flagella?

Cocci

Spirochetes move by __________.

Twisting motion using periplasmic flagella

What are fimbriae used for?

Adhesion

What is the primary function of pili?

Conjugation

What is conjugation?

Transfer of genetic material

What type of DNA is often transferred during conjugation?

Plasmid DNA

A glycocalyx is also known as __________.

Slime layer

A thick glycocalyx is called __________.

Capsule

What is the primary function of a bacterial capsule?

Protection from host defenses

What is a biofilm?

A community of microbes attached to a surface

Why are biofilms clinically important?

They are hard to treat and can form on medical devices

What are the two main components of a cell envelope?

Cell membrane and cell wall

The fluid mosaic model describes the structure of the __________.

Cell membrane

The cell membrane is composed of a __________.

Phospholipid bilayer

Proteins that span the cell membrane are called __________.

Integral proteins

Proteins associated with only one side of the membrane are called __________.

Peripheral proteins

What is the function of receptor proteins in the cell membrane?

Detect environmental stimuli

What is the cell wall made of?

Peptidoglycan

What is peptidoglycan?

A sugar/peptide complex

What is the main function of the cell wall?

Maintain cell shape and prevent lysis

Which enzyme destroys cell walls by breaking down peptidoglycan?

Lysozyme

What type of cells have a thick peptidoglycan layer in their cell wall?

Gram positive

Gram-positive cell walls are __________.

Not porous

Teichoic and lipoteichoic acids are found in __________.

Gram positive bacteria

What is the purpose of teichoic and lipoteichoic acid?

Maintain cell wall integrity and help with adhesion

Gram-negative cell walls have __________.

A thin peptidoglycan layer and an outer membrane

What is the outer membrane of Gram-negative cells made of?

Lipopolysaccharides (LPS)

What is LPS also known as?

Endotoxin

What are porins?

Nonselective channels in the outer membrane of Gram-negative bacteria

How does Gram staining work?

It uses dye to differentiate bacteria based on cell wall structure

What are mycoplasmas?

Bacteria that naturally lack a cell wall

What do mycoplasmas use to stabilize their cell membranes?

Sterols

Where is the bacterial genome located?

Nucleoid

What is a plasmid?

A small circular piece of dna

What is the process of copying DNA into RNA called?

Transcription

What is the function of ribosomes?

Protein synthesis

What is translation?

Using RNA to create proteins

What is the bacterial cytoskeleton?

A network of filaments that help maintain cell shape

What are inclusion bodies?

Storage compartments for nutrients

What is the cytosol?

The liquid portion of the cell

What are endospores?

Dormant structures that protect bacteria during harsh conditions

Which bacterial genera are known for producing endospores?

Clostridium and Bacillus

What is an autoclave?

A device used to sterilize materials by using heat, water, and pressure

What are the three basic bacterial shapes?

Cocci, bacilli, spirilla

What are pleomorphic bacteria?

Bacteria that have more than one shape

What are cocci?

Spherical bacteria

What are bacilli?

Rod-shaped bacteria

What are spirilla?

Curly-Q bacteria

What is a diplococcus?

A pair of cocci

What is a streptococcus?

A chain of cocci

What is a diplobacillus?

A pair of bacilli

What is a streptobacillus?

A chain of bacilli

What is a tetrad?

A group of four cells arranged in a single plane

What is a sarcina?

A cube of eight to 64 cells

What is a staphylococcus?

A cluster of cocci

What is a palisades arrangement?

Cells arranged side by side

Which structure is NOT an external structure of bacteria?

Nucleoid

What is the primary function of flagella?

Movement

What is the primary function of fimbriae?

Adhesion

What is the primary function of pili?

Conjugation

What is the primary function of the cell wall?

Cell shape and protection

Which of the following is NOT part of the cell envelope?

Nucleoid

What is a key component of Gram positive cell walls?

Teichoic acids

What is a key component of Gram negative cell walls?

Lipopolysaccharides