Molecules, membranes and stem cells Flashcards
What 4 Atoms are essential for life?
Carbon, hydrogen, oxygen, nitrogen
The most stable state of atoms is
when shells are filled and electrons are in pairs
pH formula is
negative of the log10 of the [H+]
pH = -log10[X]
for X=H^+
The 6 important functional groups with structures and class names are:
Hydroxyl -OH - Alcohols
Carbonyl C=O -keytones(within carbon sketeton)
- Aldehydes(at the end of carbon skeleton)
Carboxyl -COOH - Carboxylic Acids
Amino -NH2 -Amines
Sulfhydryl -SH -Thiols
Phosphate R-PO4- - Organic Phosphates
Greater Hydrogen (H+) ions then Hydroxyl ions(OH-) means the solution will be
acidic
Atoms form bonds based on
their atomic shell valenciesand, in stable compounds, approximate filled shell valencies
The first 4 shell shapes moveing up energy levels are
1s, 2s, 2p(x), 2p(y), and 2p(z)
What is a buffer?
pH buffers are compounds
that suppress changes in [H+]
e.g Water is a ‘buffer’, because it suppresses
changes in [H+] so that [H+] x [OH-] = 10-14
Why is water a ‘universal solvent’ for life?
Due the dipoles that exist within it
As water is a polar molecule it forms hydrogen bonds
This allows:
- Solvation interactions with charged compounds and uncharged polar compounds
- high reactivity with many other atoms
-cohesive and ahesive properties
-high specific heat
Name the 4 important bonds for life
Ionic
Covalent
Van der waals
Hydrogen
Membranes definition
Membranes are phospholipid polymers which are amphipathic
and spontaneously assemble mono/bilayers in water
What has high membrane permeability?
High permeability for small hydrophobic molecules
What membrane permeabilty does water have?
Limited permeability for water
Describe the 2 forces that drive the movement of molecules across membranes
Chemical gradient - concentration gradient
Electrical gradient - charge gradient
Describe the two Co-transport systems
Co-transporters couple the downward movement of one ion (driver)
to the uphill movement of another solute (substrate).
Symport:
Driver ion and substrate move in the same direction
(‘piggyback’ principle)
Antiport:
Driver ion and substrate move in the opposite direction
(‘revolving door’ principle)
