Cell Biology summary
(Cell Biology - Histology exam 2)
1
,Cells & organelles (Chapter 1) 3
Intracellular transport (Chapter 11 p.375-380 + Chapter 15) 4
Extracellular matrix (Chapter 20 p.691-708) 9
Cell cycle (Chapter 18) 11
Cytoskeleton (Chapter 17) 14
Cell communication (Chapter 16) 17
Signal transduction 19
2
, Cells & organelles (Chapter 1)
- Characteristics of the cell:
- Is essential building block of all life on earth
- Has limiting membrane (inside/outside compartments)
- Contains biomolecules (e.g. protein/RNA/DNA)
- Is autonomous unit in performing a function
- Can respond+adapt to stimuli
- Can (often) reproduce itself
- Cell types:
- Bacteria — no nucleus/other organelles
- Archaea — no nucleus, often extremophiles (= can survive under extreme
circumstances where other cells cannot)
- Eukaryotes — nucleus + other organelles, sometimes multicellular life forms (human/
yeast/maize)
- Microscopy:
- Light microscopes — use visible light to illuminate specimens; up to 200 nm
> Properties of light (speci cally its wavelength) limit neness of detail
> Investigation of plant+animal tissues with light microscope led to cell theory: all
living cells are formed by growth+division of existing cells
> Sample often has to be xed -> embedded -> sliced -> stained
> Possibility of living cells as samples
- Fluorescence microscopes — type of LM that use sophisticated methods of
illumination and electronic image processing to see uorescently labeled cell
components in much ner detail; up to 20 nm
> Fluorescent dyes used for staining
> Illuminating light is passed through 2 lters:
1. Filters light before reaching specimen, passing only wavelengths that
excite particular uorescent dye
2. Blocks out this light and passes only those wavelengths emitted when
dye uoresces
- Electron microscopes — use beams of electrons as source of illumination; up to 0,2
nm
> Electrons have much shorter wavelength -> ner details
> Similar preparation of cells as LM, but much thinner slices, no possibility of
living cells (vacuum), stained with electron-dense heavy metals, and time-
consuming method
- Transmission EM — used to look at thin sections of tissue; similar to LM, but
transmits beam of electrons through the sample instead of light
- Scanning EM — used to look at surface detail of cells and other structures;
scatters electrons o the sample surface
> Compartments:
- Condenser — controls beam of electrons / spotsize
- Objective — focuses image
- Wobbler — moves specimen in focal plane
- Apertures — lter out scattered electrons
3
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(Cell Biology - Histology exam 2)
1
,Cells & organelles (Chapter 1) 3
Intracellular transport (Chapter 11 p.375-380 + Chapter 15) 4
Extracellular matrix (Chapter 20 p.691-708) 9
Cell cycle (Chapter 18) 11
Cytoskeleton (Chapter 17) 14
Cell communication (Chapter 16) 17
Signal transduction 19
2
, Cells & organelles (Chapter 1)
- Characteristics of the cell:
- Is essential building block of all life on earth
- Has limiting membrane (inside/outside compartments)
- Contains biomolecules (e.g. protein/RNA/DNA)
- Is autonomous unit in performing a function
- Can respond+adapt to stimuli
- Can (often) reproduce itself
- Cell types:
- Bacteria — no nucleus/other organelles
- Archaea — no nucleus, often extremophiles (= can survive under extreme
circumstances where other cells cannot)
- Eukaryotes — nucleus + other organelles, sometimes multicellular life forms (human/
yeast/maize)
- Microscopy:
- Light microscopes — use visible light to illuminate specimens; up to 200 nm
> Properties of light (speci cally its wavelength) limit neness of detail
> Investigation of plant+animal tissues with light microscope led to cell theory: all
living cells are formed by growth+division of existing cells
> Sample often has to be xed -> embedded -> sliced -> stained
> Possibility of living cells as samples
- Fluorescence microscopes — type of LM that use sophisticated methods of
illumination and electronic image processing to see uorescently labeled cell
components in much ner detail; up to 20 nm
> Fluorescent dyes used for staining
> Illuminating light is passed through 2 lters:
1. Filters light before reaching specimen, passing only wavelengths that
excite particular uorescent dye
2. Blocks out this light and passes only those wavelengths emitted when
dye uoresces
- Electron microscopes — use beams of electrons as source of illumination; up to 0,2
nm
> Electrons have much shorter wavelength -> ner details
> Similar preparation of cells as LM, but much thinner slices, no possibility of
living cells (vacuum), stained with electron-dense heavy metals, and time-
consuming method
- Transmission EM — used to look at thin sections of tissue; similar to LM, but
transmits beam of electrons through the sample instead of light
- Scanning EM — used to look at surface detail of cells and other structures;
scatters electrons o the sample surface
> Compartments:
- Condenser — controls beam of electrons / spotsize
- Objective — focuses image
- Wobbler — moves specimen in focal plane
- Apertures — lter out scattered electrons
3
fi fl fffi fififl fl fi fi fi
