Chapter 1: Bacterial Cell Structure, Physiology, Metabolism, and Genetics

6 kingdoms of life

Eubacteria, Archaeabacteria, Protista, Fungi, Plantae, Animalia

3 domains of life

Bacteria, Archaea, Eukarya

What do prokaryotes NOT have that eukaryotes DO have?

Prokaryotes do not have a true nucleus or other organelles; however, eukaryotes have membrane bound organelles (a nucleus and organelles)

Is archaea bacteria?

No!

Do archaea cause disease in humans?

No!

What is the most common living organism?

Kingdom Eubacteria (prokaryote)

What is a common kingdom protista (eukaryote)?

Marlia ,which is caused by a protist NOT by bacteria

4 components of ALL cells in general

Cytoplasm

Cell membrane

Ribosomes

Genetic material

Cytoplasm

Jelly inside that stuff floats in

Cell membrane

Outer lipid bilayer that delineates the cell from the inside

Ribosomes

Responsible for making proteins

Genetic material

Responsible for reproduction and replication

Are viruses living?

No because they do not have DNA and RNA. Viruses only can have either, but never both.

Virus fact!

Cause some of the most deadly and impactful sicknesses in the human body and are incredibly impactful to our ecosystem and relationship with microorganisms because there is nothing to treat them

Can viruses be treated?

No!

Are viruses considered organisms?

No, they are RARELY considered organisms. They're mostly considered viral particles

Where can viruses reproduce?

Host cell

Can viruses use human cells to reproduce?

Yes! Viruses use human cells to reproduce, so in order to "treat," the infected must kill their own cells, making viruses extremely deadly

Can viruses reproduce on their own?

No!

Do viruses use energy or respond to the environment?

No!

What do all bacterial cells have?

Plasma membrane, genetic material, cytoplasm, and ribosomes

MOST bacterial cells have:

Cell wall

SOME bacterial cells can have:

Capsule, flagella, pili

Capsule

Protective structure protecting the bacteria from the environment

Flagella

Long whip-like structures used for movement

Pili

Short hair-like structures used for movement and attachment

What happens if a cell wall is not made up of peptidoglycan?

It cannot be gram stained

Gram + cell wall

Purple/blue

Gram = cell wall

Pink

What is a gram stain?

A gram stain is a quick process that gives a lot of information like color, morphology, arrangement, etc.

Morphology

Shape of the individual cell

Because bacteria has a cell wall, what shapes are they confined to?

Cocci (spheres), bacilli (rod), and spiral (helical cork screw shape)

Arrangement

How multiple cells interact with each other

Staph-

clumps/clusters

Strep-

chain

All bacteria have three basic nutritional needs

A source of carbon for making most cellular constituents

A source of nitrogen for making nucleic acids and proteins

A source of energy for performing cellular functions

Autotrophs

Use inorganic carbon dioxide gas for carbon and sunlight for energy

Heterotrophs

Use organic carbon (like glucose or other

sugars) and obtain energy by oxidizing or fermenting sugars

All human pathogens are what?

Heterotrophs (Ex. E. coli vs. H. influenzae)

E. Coli

Just needs a small amount of oxygen and sugar, can grow anywhere. Equivalent to a person who eats anything!

H. influenzae

Delicate bacteria that needs a very specific amount of CO2 and only grows in the respiratory tract

Oxidation (aerobic respiration)

Requires oxygen, much more efficient than fermentation

- Every glucose consumed = 30 ATP

Fermentation

Doesn't require oxygen, less efficient

Prefix "a"

with

Prefix "an"

without

Which organisms are most successful?

Ones who can perform both oxidation and fermentation

Three major environmental factors for bacterial growth

pH, temperature, gaseous composition of the atmosphere/oxygen requirements

pH

- Low on pH scale = acidic

- High on pH scale = alkaline basic

- Middle (7) on pH scale = neutral

- Blood pH = 7.35-7.45

- Human vaginal tract = 4-5.5

- Vast majority of human pathogens fall into the neutrophile category

Temperature

- All organisms have a temperature range at which they will grow

- Optimal temperature = the best

- Psychrophiles → 0 C (freezing)

- Psychrotrophs → 20 C (room temperature)

- Mesophiles → 35 C

- Thermophiles → 65 C

- Hyperthermophiles → 100 C (boiling)

Psychrophiles

0 C (freezing)

Psychrotrophs

20 C (room temperature)

Mesophiles

35 C

Thermophiles

65 C

Hyperthermophiles

100 C (boiling)

5 categories of oxygen requirements

Obligate aerobes, obligate anaerobes, facultative anaerobes, aerotolerant anaerobes, microaerophiles

Obligate aerobes

Required to have oxygen

Obligate anaerobes

Cannot have oxygen, oxygen is toxic to them

Facultative anaerobes

Organisms that prefer oxygen, but can go without

Aerotolerant anaerobes

Don't use oxygen, but aren't killed by it

Microaerophiles

Can't have too much oxygen, can't have too little

Which is most successful?

Facultative anaerobes

Bacterial Growth Curve

The rate at which bacteria grow

Lag phase

Happens after inocculation, bacteria are metabolising, not dividing yet

Exponential phase

Most "happy," have all the food they need, continuously growing and dividing, not swimming in their own waste yet

- Lab testing occurs in this phase

- Observed every 16-24 hours

Stationary phase

Bacteria start running out of nutrients and space, and they begin producing so much waste that they begin to swim in it, which kills a lot of bacteria.

- Equal amounts of death and reproduction

Death phase

Closed system, nothing goes in or out

Gene Transfer

Vertical transmission, horizontal transmission, transformation, transduction, conjugation

Vertical Transmission

Moves from one generation to the next

- Ex. Reproduction (creating a new organism)

- Plasmid transferred during replication to daughter cells

- Parent to offspring

Horizontal Transmission

Organism to organism within a single generation

- Plasmid transferring to other bacteria of the same generation

- Humans are not capable of horizontal transmission and most animals cannot either

- Ex. Cannot exchange DNA by asking for it

Transformation

Picks up dead DNA

Transduction

Through virus

Conjugation

Exchange directly through a pileus

- Closest that bacteria get to sex