Chp 1 Flashcards
Robert Hooke
Discovered Cells in a piece of cork; created microscope
Robert Hooke Year
1665
Anton van leeuwenhoek year
1674
Anton van leeuwenhoek
increased the magnification to 200x
Schleiden & Schwann
1838 created 1st two tenets of the cell theory
1st two tenets of cell theory
- All organisms are composed of one or more cells
- The cell is the structural unit of life
Virchow
1855 - proposed the third tenet of cell theory
Third tenet of cell theory
- cells can only arise by division from a preexisting cell
Pasteur’s Experiment
1864 - two flasks both boiled then incubated; the curved flask didn’t grow bacteria the open flask did.
Pasteurs Conclusions
- support for germ theory/against spontaneous generation
- cells are in the environment
- cells need nutrients to grow and divide
Sterilization
high temperature and high pressure; extends shelf life by months; loses nutritional value; kills spores
Pasteurization
low heat treatment; nutrients remain; kills microorganisms
Ionic bonds
- bond between oppositely charged ions
-electronegativity >2.1 - metal and non metal
Electronegativity Differences
Non-Polar Covalent - <0.5
Polar Covalent 0.52.1
Covalent
- two nonmetals
-sharing of electrons
hydrogen bonds
interaction of H and the lone pain of N,O,or F; highest boiling point
hydrophobic interactions
- avoid polar molecules
van der Waals attraction
induces charge fluctuation; distance dependent
Why are covalent bonds critical to biological systems?
-very stable and are what make most biological molecules
- allows more complexity in life
Properties of Water
- high polarity
- excellent solvent
- high heat capacity
-cohesive and adhesive properties - less dense as a solid
pH formulas
pH=-log[H+]
[H+]=10^-pH
