Microbiology - Exam 1 Ch. 4 - 8 (Nomenclature, Cultivation, Eukaryotic cells, and Viruses)

Classification depends on…

Cell and Colony morphology
Growth Characteristics
Biochemistry
Physiology
DNA sequence data

Species

Group of strains sharing common features while differing considerable from other strains.

Genus

Group of closely related species

OTU stands for…

Operational Taxonomic Unit

ASV stands for…

Amplicon Sequence Variant

Shapes of bacteria

Coccus (circular)
Bacillus (rod)
Vibrio (curved rod)
Spirillum/spirochete (spiral/squiggle)

Arrangements

Mono (1)
Diplo (2)
Tetra (4)
Staphylo (pyramid shape)
Strepto (line)
Sarcina (4X4 cube)

Factors that influence growth

Temperature
pH (acidophiles, neutrophiles, and alkaliphiles)
Oxygen
Nutrients

Macronutrients

C (carbon)
H (hydrogen)
O (oxygen)
N (nitrogen)
P (phosphorus)
S (sulfur)

Broth

Liquid growing medium for bacteria (test tube)

Agar

Solid growing medium for bacteria (plate)

Complex Media

Do not know exact composition

Defined Media

We do know exact composition

Selective Media

Used to grow specific microorganisms

Differential Media

Used to distinguish between different microorganisms

Steps of binary fission

1. Growth

2. DNA replication

3. Chromosome separation

4. Seperation (cytokinesis)

5. Division

Direct counts

Observe the # of cells
Serial dilutions, membrane filtration, Petroff-Hausser counting chamber, FISH

Serial dilutions

Purpose is to estimate the concentration of a sample CFU (colony forming units)

Membrane filtration

Used to isolate and count microorganisms in liquid samples

Petroff-Hausser counting chamber

Use a microscope to count the cells on a grid

FISH

Identify and quantify specific groups of microorganisms

Indirect counts

Spectrophotometry, Lag phase, Exponential phase, stationary phase, and death phase.

Spectrophotometry

Measures absorbance and how much light is transmitted through a light-sensitive detector.

Lag phase

Bacteria cant replicate after being introduced to a new environment

Exponential phase

Bacteria rapidly multiply and divide at a constant rate

Stationary phase

The rate of cell division equals the rate of cell death

Death phase

The rate of cell death is greater than the rate of cell division (formation)

Fastidious bacteria are _________

Ulculturable

Fastidious bacteria

A bacteria that require special conditions and substances for growth.

Fungi cell wall is made of ______

Chitin

Algae cell wall is made of _________

Cellulose
Pectin, mannuns, minerals

Nucleus

Membrane bound
Double phospholipid bilayer
Contains DNA (chromosomes)
RNA synthesized here
Nucleolus inside: Ribosome constructed, rRNA transcription, rRNA → proteins

Ribosome

Site of protein synthesis
Prokaryotic: 505+305=705
Eukaryotic: 605+405=805

Mitochondria

Site of cellular respiration and ATP production

Endosymbiotic Theory

Theory that mitochondria and chloroplasts originated from prokaryotic cells

Chloroplasts

Responsible for Photosynthesis
Contain Chlorophyll, responsible. for the green color in plants

Algae are _____________ and generate their own food

Photoautotrophs

Algae are ___________, and contain only one cell

Unicellular

Trophozoite

The active feeding stage

3 characteristics of Protozoa

1. Eukaryotic

2. Unicellular

3. Lack a cell wall

Chemoheterotrophs

Feed off of other organisms

Helminths

Multicellular animals with organs and organ (worms)

Flatworms

Very thin segmented body

Roundworms (Nematodes)

elongated, cylindrical, unsegmented body

Are all fungi eukaryotic?

Yes

Microscopic fungi

• Yeast

• Mold

  • Mycelium, Spores

Meiosis

Sexual spores

(two parents)
Allows for genetic diversity

Mitosis

Asexual spores
(one parent)

Host range

The spectrum that a organism can infect

Tropism

The ability of a pathogen to infect

Bacteriophage

A type of virus that infects bacteria

Viral structure

Acellular, obligate, intracellular parasites
“ultramicroscopic”
DNA or RNA

Endocytosis

How a virus enters a host

Steps of replication of a virus

1. Attach

2. Enter

3. Synthesis (genome and proteins)

4. Assembly

5. Release

Permissive cell

Cells that support viral replication determine host range and tropism

Burst size

The # of new viruses that burst out of an infected cell

Burst time

From when the virus attaches until the virus releases

Plaque

Dead

Clear area formed by cell lysis

Colony

Visible growth of an organism in a medium

How are viruses classified?

ICTV and Baltimore system

ICTV

International committee on taxonomy of viruses
Order → Family → Subfamily → Genus → Species

Baltimore System

7 category system that are genomic based

Viral infection outcomes

1. Acute infection

2. Chronic infection

3. Lutent infection

4. Transformation

Viroids

RNA Viruses

RNA replicase

Replicates RNA virus’s genome

Prions

Proteins that have been misfolded that then cause disease.
Infect the brain

Satellite Viruses

Need another virus for infection