Intro to Cell Biology

Janssen and Janssen
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Terms in this set (34)
Janssen and Janssen
Produced first compound microscope in 1590
Hooke
Discovered chambers in cork - the dead remnents of cells
van Leeuwenhoek
Described many living cells: "animacules", red blood cells, sperm, micro-organisms
Schleiden and Schwann
Proposed first 2 tenants of cell theory
Virchow
Added the third tennant of cell theory
The three tenants of cell theory
1. The cell is the smallest building element of a multicellular organism and as a unit is itself an elementary organism
2. Each cell in a multicellular organism has a specific task to accomplish and represents a working unit
3. A cell can only be produced from another cell by cell division
Lynn Margulis
Proposed the endosymbiont hypothesis in 1968 - that mitochondria are descendents of bacteria taken up by other cells
Liposomes
Called "artificial cells" but aren't really..... they are a kind of vesicle used to carry drugs into the body.... as well as uses in other areas such as cosmetics, food and dyes
Size of a ribosome
30 nm in diameter
Size of a DNA molecule
2 nm wide
Size of the lipid bilayer5-7 nm wideCell cultureA technique used to grow cells outside the organismPrimary cultureUses cells obtained directly from the organismSecondary cultureUses previously cultured cells to culture more in a new mediumClonal cultureDerived from a single colony of cells... or even 1 cellAxenic culturePure population of cells - contains cells from only one speciesContact inhibitedNormal cells will stop dividing once they touch a neighbouring cellProperties of normal cellsContact inhibited Growth factor dependent - in a culture this requirement is met with a serum Anchorage dependent - Must be attached to a solid substrate, in culture typically a dish coated with molecules similar or the same as those found in the extracellular matrix they would typically encounter Finite Lifespan - they will eventually reach a point where they cannot perform more mitosesHayflick LimitMaximum number of doublings in cultureCell linesLineage of transformed cellsCell strainsLineage of normal cellsWays to grow cells1. suspended in a liquid nutrient medium - transformed cells can grow this way 2. suspended in a semi-solid nutrient medium - transformed cells 3. plated on the surface of a semi-solid nutrient medium - bacteria 4. plated on the surface of a solid substrate bathed in a nutrient medium - normal cells only grow this way - transformed cellsTrypsinUsed to harvest cell culture - it splits bonds that cells have madeProperties of transformed cells- loss of growth control - anchorage independent -growth factor independent - not contact inhibited - can continue dividing well beyond the typical hayflick limitTumourAn abnormal growth of tissueMalignant tumourAbnormal growth with evidence of being locally invasive, possibly metastaticBenign tumourAbnormal but non-invasive growth - does not spread to other parts of the bodyIn order to use the whole organism to obtain a tissue or organ sample:Use dissection, vivisection, euthanasiaSample is separated into single cells usinga. mechanical disruption - blender, homogenizer etc b. enzymatic disruption - release of proteases such as trypsinEagle's Basal MediumBasic medium for animal cell culture, contains: Amino acids - for protein synthesis Vitamins - components of coenzymes Salts - maintain tonicity and membrane potential - components of buffers - gradients for transport Glucose - carbon and energy source Antibiotics - reduce risk of bacterial contamination Phenol red - pH indicator - mimics estrogen Serum - contains growth factorsCryobiologyStudy of the effects of low temps on organisms or the use of cryopreservationAdvantages of Cryopreservation-ensure cells will always be available -allows experiments to be performed multiple times on effectively the same cells -cells can be stored for additional work - true suspended animationCryoprotectantsHelp to prevent damage caused by the freezing process, however they only work if freezing is done slowly, do little to help against formation of interior ice that is caused by fast freezing.Effect of extracellular ice formation-Crushing damage -Increase of solute in the external environment leads to loss of water in the cell