9/22/11

Today we started Unit 2, which is about cells and organic chemistry. We took notes in our yellow packet. Here are some important notes:

• Carbon atoms can bond to four atoms


• Carbon skeletons can be long and may be branched or unbranched


• Four macromolecules (biological molecules) are: proteins, carbohydrates, lipids, and nucleic acids (DNA & RNA)


• Hydrocarbons are the simplest organic compounds


• Three different ways to show bonds are: structural formula, ball-and-stick model (they are 3D and show that the angles are congruent for each atom), and the space-filling model


• Functional groups are reactive


• A molecule can have one OR more than one functional groups attached


• Amino acids have 1 hydrogen atom, 2 functional groups (amino and carboxyl), and a side group (R), which is different for all 20 amino acids


• Monomers: A chemical subunit that serves as a building block for polymers


• Polymers: A macromolecule consisting of many monomers (identical or similar) bonded together (form a peptide bond, a polypeptide has around 100 amino acids)


• Dehydration Synthesis: (Dehydration = removing water) Monomers form a polymer - taking H (hydrogen) from one molecule and OH (alcohol) from the other molecule


• Hydrolysis: (Hydro = water, lysis = to break) A polymer is broken down into monomers - splitting

CARBOHYDRATES

• Monosaccharides: (Mono = single, sacchar = sugar) Simple sugars (formula for sugar is C6H12O6)...ex. glucose and fructose


• Disaccharides: (Di = two) Formed by dehydration synthesis of two monosaccharides...ex. maltose and sucrose


• Almost all carbohydrates are hydropholic (water loving - dissolves in water)

POLYSACCHARIDES

• Poly = many


• Starch ~ found in plants, glucose monomers, linear


• Glycogen ~ found in animals & human livers, stores excess sugar, branched


• Cellulose ~ found in plants, most abundant organic compound, can't be hydrolyzed (broken down by water...remember hydrolysis)

LIPIDS

• Fats


• Hydrophobic: (water fearing - don't mix with water)...Oil and water


• Glycerol + 3 Fatty Acids (triglyceride)


• Use dehydration synthesis to bind glycerol and fatty acids

STEROIDS

• Hydrophobic - classified as lipids


• Cholesterol: necessary for body functioning, base to produce other steroids


• Anabolic Steroids: variation of testosterone, makes muscle cells enlarge


• Steroid use causes many medical issues, like organ damage, infertility, and birth defects


• Effects on Teens: life expectancy goes down, livers grow tumors, guys grow breasts/girls grow beards (gender mix-up), messes up hormones

PROTEINS

• Primary Structure: Specific sequence of amino acids, linear, slight changes can affect proteins ability to function


• Secondary Structure: Alpha Helix (like a spiral staircase) and pleated sheet (like a folded piece of paper) - held together by hydrogen bonds


• Tertiary Structure: 3D, held by chemical bonds between side groups


• Quaternary Structure: Protein - consists of two or more polypeptide chains


• Proteins are polymers of amino acid monomers


• Types of proteins: structural, storage, contractile, transport, defensive, signal, and enzymes


• Enzyme: type of protein that acts as a catalyst (speeds up rate of chemical reaction, "recycled" - doesn't use itself up), lowers activation energy (amount of energy needed to stimulate reactants to react in a chemical reaction)


• Metabolism: Chemical reactions occuring inside an oganism collectively

NUCLEIC ACIDS

• Provide directions for building proteins


• DNA (genetic material - genes) & RNA (helps translate genetic code to make proteins)

Next Scribe: Emma