AS MicroScopes Flashcards
What is the first lens light focused through in optical Microscope?
- Light focused through condenser lens
What is the first step in Optical MicroScope?
Light is focused through condenser lens then through
Specimen where certain wavelength are filtered.
After light is passed through condenser lens in optical microscope where is light then passed?
Light then passes through objective lens then to eyepiece lens to produce a visible image.
Which microscope has the highest Magnification?
Put the microscopes in order in descending order
Highest Magnification: TEM (Transmission Electron microscope)
2.SEM (Scanning Electron microscope)
3.Optical Microscope
Which microscope has the highest resolution?
Put them in order in descending order
1.TEM and SEM
Then optical microscope.
How does TEM electrons work?
Electrons pass through specimen and denser parts absorb more electrons so appear darker
How does Scanning Electron Microscope?
Electrons bounce off specimen and are detected at multiple detectors.
What is the first step using Eyepiece Graticule and calibrated stage micrometer to measure Actual Size?
Line up Eyepiece Graticule with Calibrated Stage Micrometer.
What is the second step using Eyepiece Graticule and calibrated stage micrometer to measure Actual Size?
Count the number graticule division that correspond with set measurement on calibrated stage micrometer.
What is the last step using Eyepiece Graticule and calibrated stage micrometer to measure Actual Size?
Calculate the distance in micrometer of one division on eyepiece graticule
What are the limitations of using an electron Microscope?
1.Can’t view live specimen due to interior being a vacuum.
2.Specimen sliced very thinly
3.Require extensive staining process which leads to artefacts.
What is the first step in Cell Fractionation?
Sample is homogenised and place in test tube with homogenate and centrifuge it and spin it at low speed
Low speed centrifuge isolate what organelle?
Isolates nuclei and nuclei pellet is separated.
After the first organelle is removed from homogenate what next is a pellet and removed?
At a higher speed the second thing organelle that is removed is mitochondria and chloroplasts.
Pellet at the bottom and removed
What needs to be removed before you get a cell free liquid?
Higher speed centrifuge Endoplasmic Reticulum and Golgi (Body) form pellet and removed.
