Intro to Microbiology- Test 1

What are the main domains of microorganisms?

Bacteria, Archea, Fungi, and Protozoa

Describe Bacteria

Prokaryotic

Unicellular

No organized Nucleus

Binary Fission

Describe Archea

Live in extreme environments

Methanogens, extreme halophiles, and thermophiles

No human disease

Describe Fungi

Eukaryotes

Distinct Nucleus

Cell wall of Chitin

Unicellular (yeast) or Multicellular (mold)

Describe Protazoa

Eukaryotes

Unicellular

Some are photosynthetic

Some cause disease like amebic dysentery

What are the major milestones of Microbiology

1876- Koch proves bacteria cause disease

1884- Gram develops stains

1928- Fleming Discovers penicillin

Modern developments?

Recombinant DNA tech

Biotech applications

Study of emerging infectious diseases

Microbes in human health and ecology

What are good things microbes do?

Make food

recycle sewage

vitamin synthesis

medical treatmens=ts

What are the 3 domains of life?

Bacteria

Archea

Eukarya

Order of Taxonomic Hierarchy

Drunk King Phillip Came Over From Great Spain

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Key differences between bacteria and archea?

Both are prokaryotic with no nucleus

Archea has no peptidoglycan but has pseudomurein

Archea live in extreme areas

Both are single celled, lack membranes-bound nucleus, but arches have distinct cellular and genetic characteristics that set them apart

What are the main types of microorganisms studied in microbiology?

bacteria

archaea

fungi

protozoa

algae

viruses

and multicellular animal parasites

What disproved the theory of spontaneous generation?

Pasteur used s-beaker in 1861 to prove that organisms do not arise spontaneously.

Curve allowed air but not microorganisms to enter which resulted in the broth not becoming cloudy for an extended period of time.

Led to aseptic technique development

What must be used to view microorganisms?

Microscopes

What are the types of microscopes?

Compound Light

Specialized (dark field, phase-contrast, fluorescence, and electron microscopes)

Describe Compound light?

Basic microscopes resulting in picture on white background.

light→ condenser→ specimen→ objective lens→ optic lens

Describe dark field?

Light images against dark backgrounds

Describe Phase contrast?

Visualize internal details through refractive index differences

Describe Fluorescence?

Use ultraviolet light to see specific structures

Describe Electron microscopes?

Extremely high magnification and detailed images

Light goes top to bottom on these

What is a simple stain?

Uses a single dye to increase contrast.

What is a Differential stain?

Separates bacteria into groups (Gram Stain)

What is a Special stain?

Highlight specific structure like flagella, capsules, or spores.

What is a Gram stain?

Separates bacteria into Gram Positive or Gram Negative based on cell wall composition.

What is Acid-Fast Staining?

Uses lipid-based staining to identify specific bacteria like Mycobacterium.

What is a transmission electron microscope (TEM)?

Requires dehydrated, ultra thin, specimens (usually laid with some form of sense metal like gold or silver).

What is a scanning electron microscope? (SEM)

Provides detailed 3D image of surface.

What is a scanned probe microscope?

Probes alter surface.

What are the two main sets of lenses in a compound light microscope?

Objective which directly magnifiers the specimen

Ocular which magnifies image (final view)

How to calculate total magnification?

Objective x Ocular (usually always 10x)

What are the objective lens magnifications?

Scanning lens- 4x

Low dry lens- 10x

High dry lens- 40x

Oil immersion- 100x

What is immersion oil used for?

It prevents the spreading of light as it hits the specimen which allows for high resolution images.

Key difference between brightfieqld and dark field?

Brightfield- image against bright background

Darkfield- image against dark background

What type of microscope uses ultraviolet light instead of visible light?

Flouorescence microscopes

Prokaryote cell type?

Prokaryotes- simple no membrane bound nucleus

Small cells (0.2-1.0um)

Single circular chromosome

no histones or organelles

bacteria and archaea

Eukaryotes cell type?

Larger structured cells

Paired chromosomes in nuclear membrane

Multiple organelles (like mitochondria)

Animals, plants, fungi

What are the key structural differences between prokaryotes and eukaryotes?

Pro-

Composed of peptidoglycan which provides structure and prevents osmotic lysis (they don’t fall to penicillin)

Euk-

has no/ less peptidoglycan (should fall to penicillin)

both have selective permeability.

What is the endosymbiotic theory?

The first cell was prokaryotic. It consumed another prokaryote which created mitochondria and chloroplasts which then evolved further.

Prokaryotes>

No membrane bound nucleus

Nucleoid is “open concept” containing one circular chromosome

Have 70s ribosome (-50s and 30s)

Have peptidoglycan cell walls

Eukaryotes>

Membrane enclosed nucleus

Paired chromosomes

Organized with histones

Multiple organelles (mitochondria, Er, Golgi A.)

80s Ribosomes (40s and 60s)

Carbohydrate cell wall (chitin usually)

no peptidoglycan

Basic bacteria shapes?

bacillus- rods

coccus- PERFECT circles

Spiral

>Spirillum- waves

>Vibrio- V or boomerang

>Spirochete- tight swirls

Bacteria arrangement variations?

Pairs- diplo…

Clusters- staphylo…

Chains- strepto…

What does the cell wall do?

Structural support and osmotic stability

What is catabolism?

the break down of molecules to release energy

What is anabolism?

the use of energy to build complex structures

What is the enzymatic process?

Enzymes are critical biological catalysts that facilitate chemical reactions.

apoenzyme(protein portion) + cofactor(non protein activator) = holoenzyme(complete enzyme)

What is cellular respiration?

Glycolosis- glucose breakdown to make atp

Krebs cycle- oxidizes acetyl CoA

Electron transport chain- generates majority of cellular atp

Photoautotrouph

energy- light

carbon- CO2

Photoeterotroph

energy- light

carbon- organic compounds

Chemoautotroph

energy- cheical

carbon- CO2

Chemoeterotroph

energy- chemical

Carbon- organic compounds

What is fermentation?

The process of producing energy without the use of oxygen

What is anaerobic respiration?

Uses alternative electron receptors.

What are the two key players in metabolism?

catabolism- provides energy and building blocks through oxidizing molecules

anabolism- uses energy and building blocks to build large molecules (synthesizes macromolecules)

What are are the holoenzyme components?

Apoenzyme- protein portion which is initially inactive

Cofactor- Nonprotein component that acts as activator

Coenzyme- specific organic cofactor

Stages of cellular respiration?

1 Glycolysis-

occurs in cytoplasm

oxidizes glucose to pyruvic acid

produces 2atp and 2 NADH

first stage of carbohydrate catabolism

2 Pyruvic acid id oxidized and decarboxylated (turns into acetyl CoA)

3 Krebs cycle-

Occurs in mitochondrial matirx

oxidizes acetyl CoA

produces NADH and FADH2

Generates 2 ATP through substrate level phosphorylation

4 Electron Transport Chain-

ATP is produced through oxidative phosphorylation

occurs in mitochondrial membrane

Two types of fermentation?

Alcohol fermentation- produces ethanol and CO2

final electron acceptor is an organic molecule

Lactic acid Fermentation- produces lactic acid

homolactic acid- only lactic acid

heterolactic acid- lactic acid and other compounds