Zusammenfassung der Ressource
1 - Cell Biology
- 1.1 - Introduction to Cells
- Cell Size Limitation
- As cell size increases,
surface area to
volume ratio
increases
- Problems for
transport across
membrane (cell
will eventually die)
- If the ratio is too small:
- Substances don't enter the
cell as quickly as required and
waste products accumulate
- Cells may overheat as
metabolism produces heat
faster than it is lost over
the cell's surface
- Functions of Life
- Growth
- Metabolism
- Response
- Reproduction
- Nutrition
- Excretion
- Homeostasis
- Unicellular
organisms
perform all of
these functions
- Emergent Properties
- Multicellular organisms
- Caused by
interaction of
component parts of
a structure
- Cell Differentiation
- Expression of some
genes and not others
- Allows
development
of specialised
cells
- Stem Cells
- Embryonic stem cells
- Embryonic development
- Adult stem cells
- e.g. bone marrow
- Cord blood stem cells
- Therapeutic uses
- Cell Theory
- All living organisms are
composed of cells
- The cell is the
basic unit of life
- Cells arise from
pre-existing cells
- 1.2 - Ultrastructure of Cells
- Microscopes
- Electron microscopes
have higher resolution
than light microscopes
- RESOLUTION -
separate points
distinguishable
by eye
- Magnification = size of the image /
actual size of the specimen
- Light microscope: Max. resolution = 0.2
Um (200 nm) Max. magnification = x 400
- Limited by wavelength of light
- Prokaryotes
- Eukaryotes