AP Bio, Ch.3: Biochemistry Vocab

All e- in an atom ar in the lowest available energy levels

When atom absorbs energy, e- move to a higher energy level

Differing number of neutrons; they are chemically identical becuase they still have the same no. of e-

Formed when two atomic nuclei attract the same electron/s. Energy released when bond is formed, and energy must be supplied to break it.

Bond resulting from the transfer of e-

Sharing e-

Resulting structure when atoms have covalent bondssingle bond: when atoms share one pair of e-double bond: when atoms share two pairs of e--

Unequal sharing of e- (i.e: H-H vs. C-H bond) vs. equal sharing of e- (i.e. O=C=O). Polar = strong, Nonpolar = Weak

Hydrophobic: substances (i.e fatty acids, lipids, oils) not dissolving in H2O because of the phospholipid bilayer which can only be penetrated by non-polar substances
Hydrophilic: substances readily soluble in H2O

· Hydrogen bonding: strong attractions · Has High specific heat: (Able to keep stable temperature environment) · High heat of vaporization (When it evaporates, cools surfaces) · Universal solvent (Dissolves polar AND ionic substances) · Exhibits strong cohesion tension 1. Transpirational-pull cohesion tension: water moves up tall trees from roots to leaves without active transport; as one molecule of h2o is lost from leave via transpiration, another molecule drawn in at the rootes 2. Capillary action: moving up a small tube 3. Surface tension: bugs walk across water · Ice floats, less dense than water (Helps environments underneath floating icebergs and stabilizes the environment by providing fresh O2 when it melts)

Only polar substances can dissolve in polar solutions just like non-polar substances can only dissolve in non-polar solutions

-Agents that regulate pH of biological systems to prevent slight changes in pH of environments-Bicarbonates (ones found most in the body) work by either absorbing extra H+ if it becomes too acidic or adding H+ if it gets too basic

Same molecular formula, but different structures = different properties o Structural: arrangement of atoms o Geometric: spatial arrangement around double bonds o Optical/enantiomers: mirror images L- vs. D- (left-handed vs. right handed notation)

-Consist of the following: CHO, with the ratio of H:O being 2:1-Monosaccharides, Disaccharides, Polysaccharides

-Mono: chemical formula C6H12O6isomers: fructose, galactose, glucose-Di: two monosaccharides joined together with chemical formula of C12H22O11, isomers: lactose, maltose, sucrose-Poly: polymers of carbohydrates and formed by many monosaccharides joined through dehydration synthesis o Cellulose: (found in plants) makes up plant cell walls o Chitin: makes up exoskeleton in arthropods; stored in liver and skeletal muscle