Evolution: Living organisms are modified descendants of common ancestors and leads to unity/diversity of organisms
Emergence: come out from whole; whole > parts
Levels of organization is hierarchy
Methods of investigating bio: scientific method
Electrons: 25 of 92 elements essential to life; -1 charge; move rapidly; determine how atom interacts
E- shell has e- PE
Valence shell: outermost shell where bonds between e- form
Part of atom (subatomic: proton, neutron, electron)
Formation of molecules
Chemical bonds
Strength | Electronegativity | Interaction with water | intra/inter molecular | |
---|---|---|---|---|
Covalent (CH4, O2, nonpolar lipids) | Hard to break | <2 close to 0 | Don’t dissolve | Intra |
Polar (H2O, HF) | Strong | < 2 | dissolve | intra |
Ionic (NaCl, Na+, Cl-) | Weak | >2 | dissolve | intra |
Van der Waals (DNA) LDFs, Hydrogen | Attractions between different molecules | H-bonds | Inter |
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