WGU C785 Biochem Study Guide Unit 2

WGU C785 Biochem Study Guide Unit 2: Amino Acids, Peptide Bonds, Protein Structure Polar amino acids - OH, NH, SH or use SNO o Polar bears like water! Nonpolar amino acids - CH (CH, CH2, CH3) o “Can’t Have” water Ionized amino acids - the charged amino acids +/- attached to them. BACKBONE PRIMAR Y Peptide bond - chain DOES NOT denature SECONDA RY Alpha helix Beta sheet Hydrogen bond in pH Salt Reducing agent (SH) TERTIARY 3D folding QUATERNA RY Polypeptide Heat Primary – chain of amino acids, peptide bonds forming a polypeptide chain. • Peptide bonds are strong and covalent. Primary formed by peptide bonds Secondary – Carboxyl grp and amino grp. Secondary held together by hydrogen bonds. • Hydrogen bonds formed from 2 polar amino acids!!! Tertiary – 3-D shape • Sickle cell, arthritis, hemophilia Quaternary subunit – more than one polypeptide, HgB Changes seen with ↑temp R-GRP Neurodegenerative protein aggregation: Misfolding of a protein structure in Alzheimer’s Disease the most common neurodegenerative disease. The formation of the aggregated amyloid-beta fibers another characteristic of Alzheimer’s. The neurodegeneration and memory loss can be detected before the amyloid fibers accumulate in the brain. o Caused by intracellular tangles and extracellular plaques (senile plaques) caused by ABNORMAL PROTEIN AGGREGATION. o TAU is fibrous material inside cells with this the connections are lost. This becomes defective and form filaments in the amyloid-beta is a large precursor protein in the cell. o Excess amyloid-beta is clearly linked to Alzheimer’s disease creating senile plaques. Starts in the hippocampus and moves up. • Chaperones- molecules that help denatured proteins in folding (they help newly formed proteins and can also help the misfolded ones) Know the levels of protein structure • Peptide bond- peptide bonds form between 2 amino acids via DEHYDRATION reaction. During the reaction, a water molecule (H20) forms from the oxygen of a carboxyl grp and 2 hydrogens from an amino grp. As water forms, the carbon atom of the carboxyl grp and the nitrogen atom of the amino grp become bonded together. This bond between the two amino acids is called a peptide bond. • Dipeptide. A peptide composed of 2 amino acid residues Know what ionized Alanine looks like. It’s an amino acid, look for the R group, alanine is HYD [Grab your reader’s attention with a great quote from the document or use this space to emphasize a key point. To place this text box anywhere on the page, just drag it.] • ROPHOBIC that has CH3 as its weak interaction. For ionized look for the one with the + or – charge. Unit 3: Enzymology and Catalytic Mechanism Substrate: molecule that an enzyme will bind preferentially to any other molecule. Each enzyme is specific for that substrate, it won’t react with molecules that are not its own substrate. Increase substrate increase reactions Active site: enzymes have an active site, which serves as the binding platform for its specific substrates and acts as the site of the chemical reaction. Allosteric site: any site OTHER THAN the active site (in the alley) Induced fit: enzymes will adjust their active site conformation slightly as the substrate binds to improve the fit Competitive- inhibitor – bind to an enzyme at active site o Competitive inhibitor competes with active site. Increase substrate increase reaction, can be reversed. Non-competitive inhibitor – attach to the enzyme