Portage Biochem Module 6 Questions and Answers Already Passed

Portage Biochem Module 6 Questions and Answers Already Passed Most common nucleic acids Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Nucleic acid monomers nucleotides DNA function stores genetic info encoding primary sequence of proteins RNA function makes proteins from info in DNA Nucleotide structure base + monosaccharide + phosphoric acid (H3PO4) Site of phosphoric acid bonding to sugar Carbon 5 Composition of bases heterocyclic organic compounds containing N Purine structure 2 rings fused together Purine bases Adenine and Guanine Pyramidine structure single ring Pyramidine bases Cytosine, thymine (DNA), uracil (RNA) Distinction between thymine and uracil Thymine has an extra methyl group (looks like an antenna) RNA sugar D-ribose; carbon 2 has an -OH group DNA sugar 2-deoxy-D-ribose; Carbon 2 has -H Nucleoside structure base covalently bonded to ribose or 2-deoxyribose Site of base + sugar bonding anomeric carbon of sugar and N of base primary structure of nucleic acids covalent bonding of phosphate groups and sugar to form backbone 5' end phosphate group is located at carbon 5 of sugar 3' end hydroxyl group (-OH) is located at carbon 3 of sugar What dictates primary structure of DNA? Order of bases from 5' to 3' Oligonucleotide A chain of 50 or fewer nucleotides DNA secondary structure Any stable structure taken up by some or all of the nucleotides, such as a double helix DNA tertiary structure massive, more complex folding structures Discovery of DNA double helix structure 1953, Watson & Crick Erwin Chargaff Conclusions 1. Base composition of DNA varies between species 2. DNA isolated from different tissues or parts of an organism is the same 3. In DNA, A&T are equimolar; C&G are equimolar Structure of DNA double helix 2 complementary (anti-parallel) polynucleotide chains held in place by Hydrogen bonds Number of Hydrogen bonds between A and T 2 Number of hydrogen bonds between G and C 3 A, B, Z forms of DNA Variants differing by bases per turn and distance of helix rise per turn Most common form of DNA B form Z form DNA distinctions left handed helix, left handed twist, can exist when C bases become methylated Gene Chromosomal segment of DNA containing sequence to produce one protein molecule Codon A sequence of three adjacent nucleotides that encode for a specific amino acid Typical number of nucleotides to encode for a full protein 150-2000 mRNA structure single strand, complementary to DNA, contains U instead of T mRNA function carries sequence of nucleotides needed to code a protein to ribosomes tRNA function Transports specific amino acids to ribosomes; pairs with mRNA to add the amino acid to a growing polypeptide chain Typical number of nucleotides in tRNA chain 70-90 Amino acid attachment to tRNA Covalent bond anticodon sequence of 3 nucleotides on tRNA complementary to a codon for an amino acid on mRNA Production method of secondary structure in tRNA Can fold on itself by H bonding of complementary base pairs rRNA Ribosomal RNA; RNA complexed with a set of proteins to form ribosomes Ribosome composition 35% protein, 65% rRNA Size of rRNA 1 million Daltons Structure of rRNA similar to globular proteins. rRNA forms helices, proteins form a-helices, turns, and b-sheets What happens when ATP is used for energy? It breaks down to AMP or ADP with production of an inorganic phosphate; ADP and AMP can reform into ATP GTP function Formed in citric acid cycle to store energy. Can transfer a phosphate group to ADP to form ATP cAMP function Second messenger, after primary signal of adrenaline, it stimulates liver cells to export glucose actively AMP function part of energy production Feature of cAMP structure structure allows it to bind to a protein Nucleotide coenzyme functions 1. Aid in binding a substrate 2. Carrier molecule 3. Activates molecules 4. Takes part in oxidation/reduction reactions FAD (flavin adenine dinucleotide) composition ADP, ribitol sugar, flavin FAD function Shuttles H atoms from one molecule to another in enzyme catalyzed reactions cytosine structure guanine structure adenine structure thymine structure Uracil structure