Micro - Lec 1

Introduction to Microbiology

What is Microbiology?

The study of organisms too small to be seen w/out magnification. These organisms are commonly referred to as microorganisms or microbes.

What do microorganisms include?

* Bacteria
* Viruses
* Fungi (mushroom, yeast)
* Protozoans
* Algae
* Helminths (Parasitic Worms)

What are all organisms made of?

All organisms are made of cells

How many types of cells in life?

Life exits as two different cell types

What is prokaryotic cell?

Very small cells that lack complex internal structures such as nucleus and organelles

What is eukaryotic cell?

Cells that contain a nucleus & membrane-bound organelles

Are microbes prokaryotes or eukaryotes?

Microbes can either be prokaryotes or eukaryotes

Do prokaryotes have nucleus?

No

Do eukaryotes have nucleus?

Yes

What type of genetic material does prokaryotes have?

Single circular DNA

How many copy of DNA does prokaryotes have?

One copy

Where are DNA located in prokaryotes?

Inside the cell

Why does prokaryotes have only one copy of DNA?

Since they are very tiny

Does prokaryotes have organelles?

No

What type of genetic material does eukaryotes have?

Linear segmented DNA

How many copy of DNA does eukaryotes have?

Multiple copies

Where are DNA located in eukaryotes?

Inside nucleus

Does eukaryotes have organelles? Give examples

Yes. Mitochondria for energy synthesis, nucleus, cell membrane, etc.

How many ribosomes does prokaryotes have?

70s ribosomes

How many ribosomes does eukaryotes have?

80s ribosomes

What types of body plan does prokaryotes have?

All multicellular

What types of body plan does eukaryotes have?

Multicellular or unicellular

What is organelles?

Internal compartments in cells that are surrounded by one or more membranes

When did first simple prokaryotes appear?

About 3.5 billion years ago. They were the only form of life for half of the earth’s history

When did eukaryotes appear?

About 1.8 billion years ago.

Once appeared, what did the earliest eukaryotes look like?

They were similar to protozoans and algae

What did appear about 1 billion years ago until now?

Reptiles → roaches, termites → mammals → humans

Why are viruses considered as microbes?

Since they are microscopic & can cause infections & diseases

Are viruses large particles?

No, they are small particles

Are viruses cells and belongs to eukaryotes/or prokaryotes?

Viruses are not cells and are not prokaryotes or eukaryotes

What do viruses compose of?

Composed of protein coat (capsid) surrounding genetic information (DNA)

What can viruses be classified as?

Obligate intracellular parasites

Do viruses have ribosomes?

No, they don’t

Can viruses make proteins by themselves? Why?

No, they cannot since they don’t have ribosomes

What viruses take proteins from?

They take proteins from the host

Are viruses dependent or independent on the host cell’s machinery for their activities?

They are highly dependent on the host cell’s machinery for their activities

How is dimensions of macroscopic?

Visible to human eyes, dimensions given in meter, cm, and mm

How is dimensions of microscopic?

* Invisible naked eyes
* Fall within the range of micrometer (um) or nanometer (nm)

Which lab equipment can be used to observe microscopic?

Microscopes

What types of microbes that we can observe under microscopes?

Bacteria

What types of microbes that we can observe under electronic (powerful) microscopes?

Viruses

What does ubiquitous mean?

Found everywhere

Are microbes ubiquitous?

Yes, they are. They can live by themselves, no host dependent

What are lifestyle diversity of microbes?

* Free-living
* Parasites
* Some are photosynthetic

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Which lifestyle of microbes take majority?

Majority are free-living & obtain all food from environment

What are parasites?

Parasites are organisms that live on or within another organisms (host), from which it obtains nutrients and produce some degree of harm in the host

What is photosynthetic in microbes?

A light derived reaction that makes organic compounds from carbon dioxide: CO2 + H2O + light → C6H12O6 + O2

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What types of microbes do photosynthetic occur?

Occurs in plants, algae, and some bacteria

Are bacteria prokaryotic or eukaryotic?

Prokaryotic

Are bacteria unicellular or multicellular?

Unicellular

What is lifestyle of bacteria?

Mostly free-living

Does photosynthetic occur in bacteria? Give examples

Yes. Some are photosynthetic. Ex: Cyanobacteria

Are bacteria pathogenic? Give examples

Yes, some are pathogenic. Ex: E.coli have beneficial while some cause diarrhea

Are fungi prokaryotes or eukaryotes?

Eukaryotes

Does fungi have ribosomes and chromosomes?

Yes

Is fungi (mushrooms) a plant?

No, fungi (mushroom) is not a plant

Is fungi multicellular or unicellular. Give examples

Unicellular (yeast) and multicellular (mold: mushrooms, things on walls)

Does photosynthetic occur in fungi?

No photosynthetic

Are fungi saprobes or parasites? What are saprobes?

* Fungi are saprobes
* Saprobes are microbes that decompose organic remains from dead organisms

Does fungi have internal or external digestion?

Fungi has external digestion that releasers enzyme into the planet, break down the food, and absorb again

Does fungi have the same digestion type to humans?

No, fungi has external digestion that is opposite to human who has internal digestion

Are protozoans prokaryotes or eukaryotes?

All eukaryotes

Are protozoans multicellular or unicellular?

Unicellular

Do protozoans have internal or external digestions?

They have internal digestions

Why protozoans are not one type of yeats even both are unicellular?

Since protozoans have internal digestions whereas yeast has external digestion

What are lifestyle of protozoans?

Can be free-living or parasites

Can protozoans move?

Yes, they can move a lot

Which parasites cause protozoans?

Malaria causes some types of protozoans

Are algae prokaryotes or eukaryotes?

Eukaryotes

Are algae unicellular or multicellular?

All unicellular or multicellular (sometimes colonial)

Give examples of algae multicellular?

Seaweed or kelps

Do photosynthetic occur in algae?

Yes

Can algae live w/out water and why?

No, they can’t since algae are always water-associate

Why do algae always water-associate?

Since algae are not plants, they must be in water all the time

Do plants need to be in water all the time as algae?

No, plant do not need to be in water since they can retain water through the root

Are helminths prokaryotes or eukaryotes?

Eukaryotes

What is classification of helminths?

Parasitic worms

Are helminths unicellular or multicellular?

Multicellular

Where do helminths present?

Raw food

Do helminths have organelles?

Tends to have a lot of organelles

Can helminths be observer through naked eyes?

Yes

Why we still need microscope to observer helminths?

Because of its eggs are very tiny

Why are helminths considered a type of microorganisms even though we can see them on naked eyes?

Because we need to use microscope to see helminth’s eggs that is so tiny

List 4 majority benefits of microbes?

* Decomposition
* Nutrients production and energy flow
* Production of food, drugs and vaccines
* Bioremediation

What is decomposition? Give examples

* The breakdown of dead organic matter
* Ex: things died they got broke down, animals died the bacteria and fungus around them break into soil

How do microbes bring beneficial to nutrients production and energy flow?

N,S,P put into the environment => microbes provide more O2 to planet than the plants do

How are microbes beneficial to food, drugs and vaccines production?

* Microbes provide a lot of food (yogurt, bread, kimchi,…)
* Drugs (fungus produces antibiotics, insulins, hormones regulate level of blood pressure)
* Vaccines (hep B,…)

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What are pathogens?

Are disease-causing organisms

How many different microbes are pathogenic?

2,000

How many infections per year worldwide?

10 billion infections

How many deaths per year worldwide?

12 million deaths

How many microbes caused infections/deaths in U.S?

Two: influenza (#7) and blood stream infections (#10)

Why do U.S has fewer infections than worldwide?

Because they have good vaccination programs in order to prevent pathogens from microbes

Why microbes are top killer around the world?

Due to lack of vaccinations, good of medical care, environments, pollution (not cleaned drinking), overcrowding countries

What is Anton van Leeuwenhoek best known for?

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* He hand-fashioned a single-lens microscopes that magnified up to 300x
* First to observe living microbes which he called “animalcules”

Define spontaneous generation

For thousands of years, people believed in the spontaneous generation, the idea that living things can rise from vital forces present in non-living or decomposing matter, since they did not know the existence of microorganisms

Who was an advocate of the Theory of Biogenesis?

Louis Pasteur

Define Theory of Biogenesis?

Louis Pasteur stated that living things arise from others of the same kind “all life is from life”

When did Louis Pasteur demonstrate that microbes are present in the air?

In 1861, Louis Pasteur demonstrated that microbes are present in the air

Louis Pasteur Inventions and Achievements?

* Disproved spontaneous generation of microbes
* Showed microbes caused fermentation & spoilge
* Developed pasteurization = heating liquid
* Developed a rabies vaccine