Lecture 3 - jennifer Intro To Microbial Diversity Flashcards
Difference between magnification and resolution
Magnification can be increased without limit
Resolution cannot be increased without limit
What is magnification
How much an image is enlarged under a microscope
What is resolution
The amount of detail you can see in an image
What is the resolution of a light microscope in µM
0.2 µm
Will increasing the magnification improve resolution
No the image will blur together and be unreadable
The light microscope cannot distinguish objects smaller than what
Half the wavelength of light
What is the average wavelength of white light
0.55 micrometers
Half of which is 0.275 micrometers
Any two lines that are closer together than 0.275 micrometers are they seen as a single or double line
Single line
How will any object with a diameter smaller than 0.275 micrometers be viewed under a light microscope
Invisible or at best as a blur
What does an electron microscope use instead of light photons to image cells and cell structures
Electrons
Why is electron microscope used
Electrons provide illumination with a shorter wavelength than light photons
What is the entire system of electron microscope held in
In a vacuum
Electrons are speeded up in a vacuum until when
Their wavelength is extremely short, only one hundred thousandth that of white light
Most electron microscopes can magnify objects up to how many times
1 million times
What is the resolving power of electron microscope
0.2 nm
What is the resolving power of light microscope
0.2 µm
What is scanning electron microscopy used for
To observe external feature of cells
What are specimens coated with in scanning electron microscopy
Thin film of metal eg gold
What happens to electrons in scanning electron microscopy that are scatted
Collected to produce an image
What is transmission electron microscopy used for
Used to observe internal cell structures
Do light photons or electrons penetrate cells
Light photons
Why are thin section of cells prepared for transmission electron microscopy
Because electrons do not penetrate the cell
Name the types of microorganism
Prokaryotic
Eukaryotic
Non cellular
Example of prokaryotic microorganism
Bacteria
Archaea
Example of eukaryotic microorganisms
Fungi
Protozoa
Algae
Example of non cellular microorganism
Viruses
Prions
Does prokaryotics have nucleus
No
Do prokaryotic cells have cell wall
Yes
Do prokaryotic cells have cell organelles
No
Do eukaryotic cells have a nucleus
Yes
Do eukaryotic cells have a cell wall
Some do but many don’t
Name the cell organelles in eukaryotic cell
Mitochondria
Chloroplasts
Endoplasmic reticulum
Golgi
Where is the nucleic acid found in eukaryotic cell
In organelle called a nucleus
Bounded by a nuclear membrane
How many chromosomes in a eukaryotic cell
One or more paired linear chromosomes
Describe chromosome in eukaryotic cell
One or more paired linear chromosomes
DNA associated with histone proteins
Is nucleic acid bounded by a nuclear membrane in a prokaryotic cell
No
Describe the chromosome in prokaryotic cell
One circular chromosome
Composed of DNA associated with histone like proteins
How do cells divide in eukaryotic cells
By mitosis
How are sex cells in diploid microorganism produced eukaryotic cell
By meiosis
How do cells divide in prokaryotic cells
By binary fission
Why aren’t sex cells produced in prokaryotic cells
Organisms are haploid
Describe the cytoplasmic membrane for eukaryotic cells
A fluid phospholipid bilayer containing sterols
Describe cytoplasmic membrane for prokaryotic cell
A fluid phospholipid bilayer
Describe the ribosomes for eukaryotic cell
Composed of 60S and a 40S subunit forming an 80S ribosome
Describe the ribosome for prokaryotic cell
70S ribosomes composed of a 50S and 30S subunits
Name the structure responsible for cell shape in eukaryotic cells
Cytoskeleton
Name the structure responsible for shape in prokaryotic cell
Cell wall
Where does photosynthesis occur in prokaryotic cells
Infoldings of cytoplasmic membrane
Name the organelle in eukaryotic cells that serves for photosynthesis
Chloroplasts
Where are respiratory enzymes and electron transport chains located in eukaryotic cell
Located in the mitochondria
Where are respiratory enzymes and electron transport chains located in prokaryotic cell
Located at the cytoplasmic membrane
The mitochondrion of eukaryotic cells serves the same function as which prokaryotic organelle
The cytoplasmic membrane
What is eukaryotic cell cell wall composed of
Plant cells , algae and fungi have cell walls composed of cellulose or chitin
Do animals cells and protozoans have cell walls
No they lack
What are prokaryotic cell walls composed of
Bacteria and archaea cell walls are composed of
peptidoglycan, protein or unique molecules
Do obligate intracellular bacteria like mycoplasma,chalmydia,ureplasma have cell walls
No they have no cell walls
Name the locomotor organelle in eukaryotic cells
Flagella
Cilia
Name the locomotor organelle in prokaryotic cells
Some have flagella
