Topic 1: Cell Biology Flashcards
Cell Theory
- Living organisms are composed of cells
- the cell is the smallest unit of independent life
- cells can only arise from pre-existing cells
Exceptions to the cell theory
Striated Muscle - composed of fused cells that are multi-nucleated
Giant Algae - unicellular organisms that are very large in size
Aseptate hyphae - lack of partitioning and have a continuous cytoplasm
functions of life
metabolism, reproduction, sensitivity, homeostasis, excretion, nutrition, and growth
rate of metabolism equation
cell mass / volume
rate of material exchange
function of a cells surface area
Magnification Equation
Magnification = image/size
how do cells organize themselves
cells -> Tissue -> Organs -> systems
Stem cells
uni-specialised cells that have two qualities:
- self renewal: they can continuously divide and replicate
- potency: they have the capacity to differentiate
generated by one’s own body
Stem Cell Therapy
replaces damaged or diseased cells with healthy ones
process of stem cell therapy
- harvest stem cells from appropriate sources
- use biochemical solutions to trigger cell differentiation
- surgically implant new cells into patient’s own tissue
- suppressing the host immune system to prevent rejection
- monitoring new cells to ensure they do not become cancerous
Differentiation
differentiation involves the expression of some genes and not others in the cell genome
activation of different genes within a cell will cause it to develop differently from other cells
active genes (eukaryotic cells)
are loosely packed as euchromatin
inactive genes (eukaryotic cells)
are packed tight as heterochromatin
Stargardt’s disease
macular degeneration, and can be treated by replacing defective retinal cells with stem cells
Parkinson’s disease
death of nerve tissue, and can be treated by replacing damaged nerve cells with stem cells
Lukemia
cancer of the blood, can be treated by replacing bone marrow with stem cells