MCB 100 exam 1

what is microbiology

The scientific study of microorganisms, where are cells that are too small to see with our naked eye

Why do we study microbes?

• microbes have roles in our lives and world

• microbes role in evolution

• microbes role in the ecology of our world

where are microbes

everywhere

how can microbes be everywhere

They are very diverse and can survive under extreme conditions (very low/high pH, extreme temperatures, strange environments like on salt or ice, and they can eat strange things like petroleum, viruses, and bacteria.)

how are microbes essential to the worlds ecology

• They meet human needs with food microbes and fermentation

• Help with waste treatment, biofuels, and biomediations to help with pollution

What can microbes harmfully cause

human and animal diseases

what is the solution to stopping microbes from causing dz

• basic knowledge of microbiology helps prevent the spread and emergency of infectious diseases

to know as much as possible about the microbe so we can learn how to use the microbe safely and how to control it.

what is scientific literacy (national academies of science)

• Literacy is more about the ideas behind the scientific thinking other than hard facts

• understanding and evaluate scientific issues and how science works

• being able to understand, communicate, and discuss science topics/concepts and make informed decisions based on the information

Scientific Inquiry

(broader than the scientific method) how people explore the natural world by asking questions and exploring phenomena

Scientific method

a specific structured process of exploring the natural world, typically involving a series of steps like observation, hypothesis, experimentation, and analysis. 

What did Neil Tyson believe about scientific literacy

science will always be true weather you believe it or not

about how many microbes on earth

~5 × 10^ 30

what is the bacteria to human cell ration in a human body

~2:1 (more bacteria)

what is the ratio of virus to bacteria cell

10:1 ( more viruses)

what device was critical to the establishment of microbiology

the microscope

when was the microscope made

~1600

importance of Antonie van Leeuwenhoek

first observed microbes under a microscope

what was important about Antonie van Leeuwenhoek observations

The observations led to questions and a hypothesis about germ theory

what did germ theory propose

that microbes cause infectious diseases

what did Fracastoro contribute to microbiology

proposed that epidemic diseases were caused by transferable particles (tinder) that transmitted infection by contact

what did Bassi contribute to microbiology

discovered that the disease that infected silkworms were caused by living parasitic organisms and proposed that human diseases were also caused my living microbes

what did Henle contribute to microbiology

proposed the concept of “bad air” and that living organisms cause infectious diseases

what did Hesse contribute to microbiology

First to develop agar plates for laboratory growth of bacteria which were essential for isolating single colonies, of bacteria and other microbes

what information was taken from culturing single colonies on agar plates

observations of bacteria growth and nutrition requirements

who tested germ theory of disease

Semmelweis and Snow and Pasteur

describe Semmelweis experiment

made the connection that the lack of hand washing affected the amount of fetal deaths due to fever

describe Snow’s experiment

traced the source of a cholera outbreak to a contaminated water well by taking statistics of all the people who have died- leading to the field of epidemiology

what did Pasteur contribute to microbiology

He tested contamination based on spontaneous generation or bad air. He conducted research that showed that microbes that were in the air caused beverages to spoil leading to the invention of pasteurization.

How was scientific method applied to the study of wine fermentation

Winemakers made observations of wine spoilage. Pasteur saw that there was yeast and bacteria, which led to testing many hypotheses to discover the true cause of fermentation and spoilage by only changing one variable at a time (very controlled experiments.

what is the basic principal of microscopy

microscopy involves the generation of a magnified image from the original sample in order to resolve objects that cannot be resolved by the human eye

how does a the image appear through an microscope lens

inverted, reversed, and enlarged

what is the typical size range for an electron microscope

0.15 nanometer- to 1 micrometer

what is the typical size range for an light

100 nanometers to 1 millimeter

rank smallest to largest of a bacteria, virus, and human cell

1. virus

2. bacteria

3. human cell (largest)

how large is a virus

100 nanometers to .1 micrometers

how large is a bacteria cell

1000 nanometers to 1 micrometer

How big is a human cell

10,000 nanometers to 10 micrometers

how is the volume and resolution in an electron microscope

volume: small

resolution: high

how is the volume and resolution in an light microscope

volume: large

resolution: low

what is the resolution of the human eye

0.2 millimeters -200 micrometers

what kind of cells is a light microscope used to see

eukaryotic and prokaryotic cells

what is the purpose of staining microbiological samples

to enhance contrast and resolution by differentiating biological features that would other wise be similar

what is the range of an electron microscope

0.15nm to 1um

what is the range of light microscope

100nm to 1 mm

what is the realm of length that an electron microscope can see

nanometers

what is the realm of cells that an electron microscope can see

viruses, inside of bacteria, organells

what does TEM use in order to see transparent structures

metals because they bind to cell structures well

what does a light microscope use to see transparent samples

gram stains

What length realm can SEM see

nanometer

what is interesting about hte images seen from a SEM

they are 3D

what kind of cells do SEM useually see

viruses

does prokaryotic cell or eukaryotic cell have a nucleus

eukaryotic cell

does prokaryotic cell or eukaryotic cell lack internal membrane bound structures (organelles)

prokaryotic cells

what does it mean that a prokaryotic cell lacks a nucleus

the cell can read DNA and make protein simultaneously

what is the typical diameter for a prokaryotic cell

1.0 um or smaller

what does the category of prokaryotic cells include

• bacteria

• archaea

what does the category of eukaryotic cells include

• animal

• plant

• fungi

• protazoa

• algea

what is the diameter of a eukaryotic cell

10um in diameter

does prokaryotic cell or eukaryotic cell use flagellum

prokaryotic cells

What is the purpose of flagella

allows prokaryotes to move through their environment in response to stimuli

Describe the polar flagella arrangement

when the flagella are placed at the ends of the prokaryotes cell

Describe the peritrichous flagella arrangement

when the flagella are attached to the whole diameter of the prokaryote cells

what happens when flagella rotate in a counter clockwise motion

• they become bundled

• make runs of straight motion

what happens when flagella rotate in a clockwise motion

• they become tangled

• runs turn into a tumbling motion

what cells are encased in a cell wall

bacteria

what are the roles of bacterial cell walls

• provides shape and structure

• protects cell from osmotic forces

• can attach to other cells

• can resist antimicrobial drugs

• used to classify bacteria (gram - or + )

What is the relationship between types of runs bacteria makes when they sense a attractant

Tumbles happen less often, so the cell keeps going where the attractant concentration increases.

What is the relationship between types of runs bacteria makes when they sense a repellent

Cause more frequent tumbles, forcing the bacterium to reorient until it heads away from the repellent.

what color does a gram + bacteria wall stain

purple

what color does a gram - bacteria wall stain

pink