Microbiology - Lab 19-21

What is osmosis?

Water movement across a semipermeable membrane

What is a solute?

Compound that dissolves in a solution, including proteins, carbs, and salts or ions

What does it mean when a cell is hypertonic?

When the concentration of solutes outside the cell is higher than inside the cell; refers to the solution surrounding the cell

Hypertonic solutions move …

Out the cell

What is plasmolysis?

When water loss causes the volume of the cytoplasm to decrease, and the plasma membrane shrinks

What makes a cell hypotonic?

When the concentration of solutes outside the cell is lower than inside the cell; refers to the solution surrounding the cell

How is turgor pressure created?

Influx of water into a bacterial cell

Halophiles grow at …

Higher salt concentrations due to their ability to maintain high enough cytoplasmic concentrations of solutes, preventing excess water loss

Facultative halophile bacteria grow in …

Both low and high-salt environments

Obligate halophile bacteria grow in …

The presence of high salt

In Anaerobic respiration what is utilized?

Alternate O2

In fermentation, organic molecules act as …

Final electron acceptors

Obligate aerobes rely on …

Oxygen for cellular respiration

Facultative anaerobe use O2 for …

Aerobic respiration (can grow without)

Obligate anaerobes …

Are unable to grow in the presence of O2 (toxic)

Aerotolerant anaerobes …

Don’t use O2 to produce ATP but can grow in the presence of O2

Microaerophiles …

Use O2 for energy production, but only in low concentrations

How are infections made?

The presence or absence of O2

Gas gangrene is caused by …

Anaerobes

What is brain-heart infusion agar?

Enriched medium for the cultivation of fastidious microorganisms

Growth patterns: Obligate aerobes; Facultative; Obligate; Aerotolerant; Microaerophiles

Only at top; throughout the agar and on the top; below it; below the surface not on it; heaviest growth in a band below the surface of the agar (O2 is optimal)

When is Hydrogen peroxide made?

In the elctron transport system