Cell Biology BIO 211 || Questions and Correct Detailed Answers
Why is microscopy or imaging so important? correct answers -Structure goes along with
function
-If you can use an imaging technique to understand the structure, you may understand the
function
f.e. DNA
What does resolution mean? correct answers -How small an object you can see
What does the oscular lens (eyepiece) do? correct answers Enlarge the image
What is the issue of brightfieqld microscopy? correct answers Most cells and tissues are colorless
and transparent
-Do not have a lot of contrast
-solution: enhance contrast
What is the issue with muscle? correct answers The sample must be reasonably thin in order to
have light transfer through, if not you won't be able to see anything if it's too opaque
What is fluorescent microscopy? correct answers Certain molecules will fluoresce in the visible
range with UV light
What does the eyepiece do? correct answers The damaging UV which you don't want is blocked
off by a barrier filter
What is staining? correct answers A different dye - you can stain all the components of a cell
-The nuclei, microtubules, Golgi
,What is phalloidin? correct answers -When cell is radiating with UV light
-You have a beautiful fluorescent image of the microtubules in green and the active filaments in
red
What is a secondary antibody? correct answers -binds to primary antibody
-Since the Fc domain is constant within the same animal class, only one type of secondary
antibody is required to bind to many types of primary antibodies.
-reduces costs
What is confocal microscopy? correct answers -If you shine a light through the book, it will be
very difficult to get all the information through the book
-Instead of a cheap bulb
-We have lasers that focus on a specific plane, a few meters thick
-gets much clearer information from a section of a cell obtainable by conventional fluorescence
microscopy
-confocal is clearer, but tremendously expensive
What is advanced light microscopy? correct answers Allows you to look at unstained light
materials
-there are two main types
-phase contrast and differential interference
-enhance the very small differences in refractory
-you can see a reasonable level of detail in the cell
-you can look at dynamic events in the cell, like cell migration and division
-good for cell culture, f.e. if you want to see how well its growing and you don't want to kill your
stain so instead you use a type of phase contrast microscopy that allows you to image the cells
while they're still growing
How are microscopes limited? correct answers The shorter the wavelength (of electrons) the
better the resolution
, -the wave length of light is in the hundreds of nanometers
-you shouldn't be able to see objects smaller than about 200 nano meters
-people have broken the resolution limit
What is light microscopy? correct answers -Light microscopy is limited to .2 micron resolution
but its cheap and easy with some types of light microscopy you can look at cells
What is transmission electron microscopy (TEM)? correct answers -Chose electrons because
they have an incredibly short wave length
-Fractions of nanometers now = how much it penetrates
-Electrons have poor penetrating power -> cannot operate in normal atmospheric conditions
(must be in hard vacuum area, like outer space)
How does the transmission electron microscope? correct answers -Operates on vaccuums
-magnetic vs. glass lenses
-optical principals: the beam has to penetrate through the sample like a light microscope
-Cannot penetrate at all
-Must only look at really small molecules/viron
What do you do after you cut samples with glass/diamonds? correct answers -Collect sections
that lie on top of the copper mesh
-Enhance the contrast with stains so you can see incredible detail
Why has cryo electron microscopy imaging won a nobel prize? correct answers Cryo-electron
microscopy earns the same clarity as x-ray defraction
-x-ray defraction for proteins is a dying technique professor thinks
What is scanning electron microscopy uses? correct answers -Visualize surfaces of tissues, cells,
isolated parts
Why is microscopy or imaging so important? correct answers -Structure goes along with
function
-If you can use an imaging technique to understand the structure, you may understand the
function
f.e. DNA
What does resolution mean? correct answers -How small an object you can see
What does the oscular lens (eyepiece) do? correct answers Enlarge the image
What is the issue of brightfieqld microscopy? correct answers Most cells and tissues are colorless
and transparent
-Do not have a lot of contrast
-solution: enhance contrast
What is the issue with muscle? correct answers The sample must be reasonably thin in order to
have light transfer through, if not you won't be able to see anything if it's too opaque
What is fluorescent microscopy? correct answers Certain molecules will fluoresce in the visible
range with UV light
What does the eyepiece do? correct answers The damaging UV which you don't want is blocked
off by a barrier filter
What is staining? correct answers A different dye - you can stain all the components of a cell
-The nuclei, microtubules, Golgi
,What is phalloidin? correct answers -When cell is radiating with UV light
-You have a beautiful fluorescent image of the microtubules in green and the active filaments in
red
What is a secondary antibody? correct answers -binds to primary antibody
-Since the Fc domain is constant within the same animal class, only one type of secondary
antibody is required to bind to many types of primary antibodies.
-reduces costs
What is confocal microscopy? correct answers -If you shine a light through the book, it will be
very difficult to get all the information through the book
-Instead of a cheap bulb
-We have lasers that focus on a specific plane, a few meters thick
-gets much clearer information from a section of a cell obtainable by conventional fluorescence
microscopy
-confocal is clearer, but tremendously expensive
What is advanced light microscopy? correct answers Allows you to look at unstained light
materials
-there are two main types
-phase contrast and differential interference
-enhance the very small differences in refractory
-you can see a reasonable level of detail in the cell
-you can look at dynamic events in the cell, like cell migration and division
-good for cell culture, f.e. if you want to see how well its growing and you don't want to kill your
stain so instead you use a type of phase contrast microscopy that allows you to image the cells
while they're still growing
How are microscopes limited? correct answers The shorter the wavelength (of electrons) the
better the resolution
, -the wave length of light is in the hundreds of nanometers
-you shouldn't be able to see objects smaller than about 200 nano meters
-people have broken the resolution limit
What is light microscopy? correct answers -Light microscopy is limited to .2 micron resolution
but its cheap and easy with some types of light microscopy you can look at cells
What is transmission electron microscopy (TEM)? correct answers -Chose electrons because
they have an incredibly short wave length
-Fractions of nanometers now = how much it penetrates
-Electrons have poor penetrating power -> cannot operate in normal atmospheric conditions
(must be in hard vacuum area, like outer space)
How does the transmission electron microscope? correct answers -Operates on vaccuums
-magnetic vs. glass lenses
-optical principals: the beam has to penetrate through the sample like a light microscope
-Cannot penetrate at all
-Must only look at really small molecules/viron
What do you do after you cut samples with glass/diamonds? correct answers -Collect sections
that lie on top of the copper mesh
-Enhance the contrast with stains so you can see incredible detail
Why has cryo electron microscopy imaging won a nobel prize? correct answers Cryo-electron
microscopy earns the same clarity as x-ray defraction
-x-ray defraction for proteins is a dying technique professor thinks
What is scanning electron microscopy uses? correct answers -Visualize surfaces of tissues, cells,
isolated parts
