My next real lecture was on the chemical components of cells, a topic as exciting as it sounds. It was really just an intro lecture, aimed to revive lost high-school education.
Chemical Components of Cells
Water's molecular structure (H2O) gives it the capacity to form hydrogen bonds (sharing of a H atom). The most important property of water is that it is an excellent solvent (can dissolve many chemical stuff, like salts, sugars, acids, and other polar molecules = hydrophillic compounds). Some stuff can't dissolve in water (hydrophobic compounds), like fats and oils and stuff. This property is important when administrating drugs.
pH is the negative logarithm of the hydrogen ion concentration (??). Easier to note that <7>7 is basic. Buffers are somewhere in the middle (~7) and their inclusion limits a solution from changing pH easily.
3. Functional groups
I don't remember this term, but functional groups are specific groups of atoms within molecules that are responsible for the characteristic of those molecules (shape, polarity, reactivity, solubility). Examples.
Large molecules made by smaller molecules called monomers grouping together. Macromolecules include polysaccharides, proteins and nucleic acids (they all depend on their monomers as functional groups).
Monomer (from Greek mono "one" and meros "part") is a small molecule that joins other monomers via condensation reactions (when 2 compounds join and in the process lose a small molecule, usually water) to become polymers. Hydrolysis reactions (water is used to break a compound into smaller parts) break polymers into monomers.
6. Amino Acids
Amino acids are my favorites. Chemically, they are molecules that contain both amine (N-based chemicals) and carboxyl (chemicals that contain carboxyl groups, formula: -COOH) functional groups via peptide bonds (basically condensation reactions, but in amino acids the bond becomes CO-NH and is known as a peptide bond, just to confuse me). There are 20 standard amino acids which bond with each other, forming polypeptide chains of proteins in one of four 3D structures (primary, secondary, tertiary and quaternary). More on those later.
Monosaccharides are simple sugars (glucose, fructose). When they link up to each other via covalent bonds (sharing of one or more pairs of electrons) they become more complex: dissaccharides (maltose, lactose and sucrose), oligossaccharides and polysaccharides (starch - which stores energy in plants, and glycogen - which stores energy in animal liver and muscles).
8. Nucleic Acids
Nucleic acids are polmers made of nucleotides. Nucleotides consist of a phosphate group, a sugar (ribose in RNA and deoxyribose in DNA) and a nitrogen-containing base. Both DNA and RNA are important in forming proteins (more on this later).
Lipids are often called fats (which are a subgroup of lipids called triglycerides). They are relatively insoluble in water. Phospholipids are a class of lipids that have hydrophobic hydrocarbon "tails" and hydrophillic phosphate "heads". Because the tails don't dissolve in water, they make good membranes when arranged as phospholipid bilayers.