Microbio Exam 1

BIO 314

Microbiology

The study of small organisms

Why should we study microbiology?

Helps us understand/develop vaccines, treatments, foods, and drinks

What percent of microbes are pathogenic?

Less than 5 percent

Normal flora

All of the microbes on or in your body (aka helpers)

Pathogenicity

Potential to cause disease

Virulence

Severity of disease caused

How can normal flora become pathogenic?

If placed in the wrong place or if host is immunocompromised.

What are opportunistic pathogens?

Infections that take advantage of immunocompromised people

Nosocomial Infections

Hospital Acquired Infections such as spesis

What is the first step for pathogenic microbes?

Enter the body/cell

What is the second step for pathogenic microbes?

Stay in!

What is the 3rd step for pathogenic microbes?

Defeat the host’s defenses

What is the 4th step for pathogenic microbes?

Cause damage

What is the 5th step for pathogenic microbes?

Transmit to a new host

What domain of life do fungi fall into?

Eukarya

What is the coccus bacteria shape?

Sphere

What is the bacillus arrangement of bacteria?

Rod

What is the spirillum arrangement of bacteria?

Spiral

What is the Strep arrangement of bacteria?

Chain

What is the Staph arrangement of bacteria?

Cluster

What is the name for 2 cells?

Diplo

What is the name for 4 cells?

Tetrad

What is peptidoglycan also known as?

Murein

What is the primary component of bacterial cell walls?

Peptidoglycan

What are peptidoglycan meshes made of?

Sugars & amino acids

How big is/are the layer(s) of peptidoglycan in gram positive bacteria?

Only 1 layer; it’s a thick layer

How big is/are the layer(s) of peptidoglycan in gram negative bacteria?

Two thin layers; one outer one inner

Teichoic acid

Sugar phosphate molecules

Describe the concentration of teichoic acids & lipids in gram positive bacteria

Lots of teichoic acids; little to no lipids

Describe the concentration of teichoic acids & lipids in gram negative bacteria

No teichoic acid; lots of lipids

Is this gram positive or gram negative?

Gram negative

Is this gram positive or negative?

Gram positive

Which gram configuration is harder to treat and why?

Gram negative because it has more layers and selective porins.

exotoxins

Continually released

Endotoxins

only released upon cell death

What type of toxins do gram positive bacteria have?

exotoxins

What type of toxins do gram negative bacteria have?

endotoxins

What is the purpose of teichoic acid in nosocomial infections?

They help with attachment

What happens when a gram positive cell dies?

Teichoic acids are released, triggering immune response and inflammation

What is the benefit of having an outer membrane for a bacterium?

More protection

What is the Lipid A anchor of LPS?

It’s a toxin released during gram negative cell death

What does the release of endotoxins in gram negative cell death lead to?

Stomach issues and a host immune system overreaction

What is distinct about mycoplasma?

It has no cell wall and is the smallest known bacteria

What does the lack of a cell wall mean for mycoplasma?

Antibiotics targeting the cell wall will be ineffective

What does mycoplasma cause?

Walking pneumonia

What is a glycocalyx

A structure outside a cell wall that some bacteria have. It helps with protection, attachment, and nutrients.

What are the 3 structures that some bacteria have outside their cell wall that help with adherence?

Glycocalyx, fimbriae, and pili.

What are the 3 structures that some bacteria have outside their cell wall that help with movement?

Pili, flagella, and axial filaments

What are the two different types of glycocalyx?

Capsules and slime layers

Capsules

Tightly attached to cells and gelatinous

Slime layers

Loosely attached to the cell

Monotrichious flagella

One flagella

Lophotrichous flagella

Lots of flagella

Amphitrichous flagella

2-sided flagella (flagella attached on each end)

Peritrichous flagella

Flagella all around the bacterium

What type of flagella is A?

Monotrichious flagella

What type of flagella is B?

Lophotrichous flagella

What type of flagella is C?

Amphitrichous flagella

What type of flagella is D?

Peritrichous flagella

What do axial filaments allow for in terms of motion?

Corkscrew motions to screw into host

What is a medical infection example of axial filaments?

Syphilis

Gliding motility

Secretes large amounts of slime to glide over cell surfaces WITHOUT having to use flagella

What is a simple stain?

A single dye that can determine shape, arrangement, and size of bacteria

What is a differential stain?

When you use 2 or more dyes

What can a differential stain uncover?

Cell structures or cell types

What is gram staining?

It distinguishes gram positive and gram negative bacteria based on the composition of their cell wall

What is the first stain in the gram staining process?

Crystal violet

What type of stain is crystal violet?

A primary stain

What is the 2nd stain in gram staining?

Iodine

What does iodine achieve in gram staining?

It traps the primary stains

What is the 3rd stain in gram staining?

Alcohol

What is the significance of the alcohol wash in gram staining?

It dissolves lipids because it is a lipid solvent

What is the 4th stain in gram staining?

Safranin

After gram staining, what are purple cells?

Gram positive cells

After gram staining, what are pink and/or red cells?

Gram negative cells

What is osmosis?

The passive movement of H20 across a cell membrane

In osmosis, what direction does water flow?

From high concentration to low concentration

What happens to a hypotonic cell?

It swells due to too much water

What happens to a hypertonic cell?

It shrivels due to too much salt/not enough water

What is an isotonic cell

In equilibrium

What is passive transport?

No energy is used; molecules move WITH the gradient from high to low concentration

WHat is active transport?

ATP energy is needed to move molecules AGAINST the gradient from low to high concentration

What is sporulation

When a bacterium goes into a protective pod

When does sporulation occur

In harsh environments

How does a sporulated bacterium exit the state of dormancy?

When environmental conditions are better, the cell(s) take in water and become active “germinates”.

How can you kill endospores?

By autoclaving them (high heat and pressure)

What is cytosol?

The liquid inside the cell

What is the cytoplasm?

The space inside the cell

What is the function of the cytoskeleton?

It maintains the shape and support of the cell

What type of cells have a nucleus?

Eukaryotic cells

What type of cells have a nucleoid?

Prokaryotic cells

What is the difference between a nucleus and nucleoid?

A nucleoid has no internal membrane around it

What advantage can plasmids provide bacteria?

antibiotic resistance

What is a nucleoprotein?

A combination of proteins and ribosomal RNA (rRNA)

Why is it significant when a structure is a nucleoprotein?

It can grab nucleic acids

What do inclusions do?

They hold things such as enzymes and ATP

What is the endomembrane system?

A class of organelles that communicate with each other via membrane channels or vesicles

What are some examples of the endomembrane system?

The nuclear envelope, golgi apparatus, and endoplasmic reticulum

What are examples of energy-related organelles?

Mitochondria and chloroplasts

What are energy-related organelles?

Energy independent and self-sufficient organelles