Intro to Cell Biology Flashcards
1
Q
Cells are supplied with
A
- Proper nutrients
- Serum
- Grown at 37C in CO2 Incubator
2
Q
Primary Cell Culture
A
- Divide limited number of times
- Contact Inhibition
3
Q
Cell Line
A
- Transformed Cells (HeLa)
- Immortal
- Lose Contact Inhibition
4
Q
Morphology Primary vs Transformed
A
Primary
- elongated + ordered
Transformed
- rounded + disorganized
5
Q
Symmetric Cell Division
A
- divides into 2 identical cells from originating
6
Q
Asymmetric Cell Division
- important for?
A
- divides into 2 cells uniquely different from originating
- divides into 2 cells, one is same as originating, one different
- Stem Cell Renewal
7
Q
Progenitor Cells
A
- give rise to differentiated cells
8
Q
Embryonic Stem Cells
A
- induced to differentiate into precursors for various cell types
- pluripotent
9
Q
Embryonic Stem Cells Procedure
A
- remove inner cell mass from blastocysts
- culture ICM on fibroblast feeder cells
- dissociate surviving ES cells
- Plate ES cells on new feeder cells
- allow colonies to form
10
Q
Adult Stem Cells
A
- limited differentially
- located in stem-cell niche
- adjacent cells provide signals to self-renew or differentiate
11
Q
Induced Pluripotent Stem Cells
A
- differentiated cells with Yamanaka Factors
- Oct4, Sox2, Klf4 = embryonic stem cells
- c-Myc = cancer cells
12
Q
Anton van Leeuwenhoek Microscope
A
- grinding lenses
- naturally acute eyesight
- 200x magnification
13
Q
Bright-Field Microscopy
A
- light source
- condenser, objective, ocular lens
- only high refractive index
14
Q
Resolution
A
- ability distinguish between 2 very closely positioned objects as separate objects
- smaller resolution = better
15
Q
Resolution Equation
A
D = (0.61 λ)/(Nsinα)
16
Q
Certain parts of the cell ____ than other parts.
Waves out of phase results in ___ and ____.
Cells with __ refractive properties can ___ passage of a light beam by ___.
A
- refract more light
- interference and dim light
- high slow 1/4λ
17
Q
Phase Contrast Microscopy
A
- live “unstained” cells
- annular diaphragm and phase plate
- 1/2λ reduction – darker contrast
- phase halo
18
Q
Differential Interference Contrast (DIC) Microscopy
A
- live “unstained cells”
- use polarized light
- defines outline and detail of cell (3D look)
19
Q
Fluorescence Microscopy
A
- emit visible light when absorb light at specific wavelength
- excited with fluorochromes
- instability drops electron releasing energy
20
Q
Fluorescence Microscopy Microscope
A
- excitation filter – selects wavelength
- dichroic mirror – reflects excitation and passage of emission light
- cell specimen labelled with fluorescent dyes that have SPECIFIC excitation/emission wavelengths
21
Q
Fluorochromes
A
- allow labelling of more than one protein at same time
- DAPI = blue
- Mitotracker = red
22
Q
Monoclonal Antibodies
A
- inject mouse with antigen X = antibodies in spleen
- fuse spleen cells with myeloma cells
- transfer to HAT medium
- unfused cells die (myeloma toxic to HAT, spleen reach Hayflick limit)
- fused cells are IMMORTAL
23
Q
Immunofluorescence Microscopy
A
- kill + freeze structures
- primary antibodies bind to specific protein
- secondary antibodies (with fluorochrome) bind to primary
24
Q
Fluorescent Imaging in LIVE Cells
A
- Green Fluorescent Protein
- excited with blue light = emits green
- fused to gene of interest on plasmid + transfected
25
Confocal Microscope
- laser excite point of focus
| - only excited in focal plane pass through pinhole
26
Deconvolution Microscopy
- math procedure remove fluorescence from out-of-focus parts
- images take at different focal planes = Z-stack
- images restored by deconvolution (sharp details)
27
Two-Photon Excitation Microscopy
- two pulsed excitation photons at long wavelength
| - image thicker samples
28
Fluorescence Resonance Energy Transfer (FRET)
- 440nm --> 480nm (blue) no protein interaction
- 440nm --> 535nm (yellow) protein interaction
- energy from first protein excites the second protein in close proximity
29
Electron Microscopy
- fixed and sectioned samples (NOT LIVE CELLS)
- specimen stained with heavy metals
- light --> electron towards anode --> magnetic condenser focuses electrons on specimen
30
Transmission vs Scattered Electron Microscopy
Transmission
- thin sections of cells (intracellular structure)
- electrons hits specimen, deflect due to heavy metals
Scattered
- intact cells
- angle electron beam hits (3D structure)
31
Immunoelectron Microscopy
- primary antibody bind to protein of interest
- gold particle linked to Protein A bind to primary antibody
- electron dense spots
