AP Biology Protein & Nucleic Acids

AP Biology Course Study Guide Protein & Nucleic Acids Macromolecules Proteins (CHONS)- Monomer = Amino Acids ● Enzymes = Proteins (not all proteins are enzymes!) ● Amino acids have directionality (amino (NH2) end & a carboxyl (COOH) end). Amino acids are added on the carboxyl end through covalent bonds ● R groups differ from each amino acid (they give them their different properties such as hydrophobic hydrophilic, or ionic) ● Amino Acids are monomers that bond together with a peptide bond to form a polypeptide through dehydration synthesis (monomers join together to form a polymer through the release of Water (H2O)) ○ Multiple amino acids will form a polypeptide chain. ● Hydrolysis (A polymer is broken into monomers by adding water (H2O)) is used to break apart polypeptides into amino acids ● Protein Structure: ○ The Primary structure is determined by the sequence order of their constituent amino acid. The specific order of amino acids in a polypeptide (primary structure) determines the overall shape of the protein. They are bonded with peptide/covalent bonds. ○ The Secondary structure arises through local folding of the amino acid into elements such as alpha helices & beta pleated sheets due to their hydrogen bonds. They are bonded through hydrogen bonds (No covalent bonds). ○ The Tertiary structure is the overall three-dimensional shape of the protein & often minimizes free energy. As a result of decreasing free energy, the stability increases. They are bonded through hydrogen, disulfide, ionic bonds, & Van der Waals/hydrophobic interactions (No covalent bonds). ○ The Quaternary structure is composed of multiple peptides that come together as a single macromolecule. They have the same bonds as the tertiary structure (No covalent bonds). Nucleic Acids (CHOPN)- Monomer = Nucleotides (consists of a Nitrogenous base, a 5 carbon sugar, & a phosphate group) ● Covalent bonds are formed between nucleotides (monomers) to form Nucleic Acids (polymer) through Dehydration Synthesis. The phosphate end of one nucleotide bonds to the hydroxyl 3’ end of the other nucleotide. ● Hydrogen bonds connect the nucleotides in one strand to the opposite strand (seen in DNA structure), or between the nitrogenous bases. ● Nitrogenous Bases: ○ There are 2 types of nitrogenous bases (purine = 2 rings & pyrimidine = 1 ring) ○ Purine = Adenine & Guanine ○ Pyrimidines = Thymine, Cytosine, & Uracil (RNA) ○ Cytosine - Guanine (3 hydrogen bonds) ○ Adenine - Thymine (2 hydrogen bonds -> These pairs will break apart more easily because they have less hydrogen bonds) ● DNA and RNA Comparison Both DNA ● Have 3 components: ○ 5- carbon sugar ○ Phosphate group ○ Nitrogenous Base ● Nucleotides are joined RNA ● Double stranded ● Single Strand ● 5-Carbon Sugar is ● 5-Carbon Deoxyribose ● Thymine (not Uracil) Ribose ● Uracil ● Runs Antiparallel together with covalent ● Hydrogen bonds bonds to form a linear hold the two molecule strands together ● 5’ & 3’ ends by connecting the ● Nitrogenous bases strands’ perpendicular to the Sugar is nitrogenous bases. sugar-phosphate backbone Carbs- 1C:2H:1O They function to provide readily available energy to organisms & also functions as a monomer of polysaccharides Lipids- 1C:2H:Very few Os ● There are many kinds of lipids, but they are all characterized by the fact that they are hydrophobic and nonpolar. ● Phospholipids ○ They are amphipathic (has a polar & nonpolar end). It functions as a component of cell membranes