Biochemistry WGU Quiz Questions and Correct Solutions

RNA polymerase - Enzyme that facilitates transcription Transcription - synthesis of an RNA molecule from a DNA template Ribosome - Large macromolecular complex where proteins are synthesized tRNA (transfer RNA) - Form of RNA that is complementary to mRNA. Has a neucleotide anticodon on one end and an amino acid in the other. Translation - decoding of a mRNA message into a polypeptide chain Coding strand (DNA) - The original strand off which the new nucleotide sequence is based. Almost the same as mRNA template strand (DNA) - The strand mRNA uses to make a copy. Complementary to mRNA missense mutation - base substitution results in change in an amino acid nonsense mutation - changes a normal codon into a stop codon silent mutation - change in DNA that codes for the same amino acid Replication - process of copying DNA prior to cell division DNA polymerase III - synthesizes new DNA only in the 5' to 3' direction Needs a primer to start polymerase chain reaction (PCR) - Copying DNA in lab. Used to study/diagnose PCR needs - Target DNA dNTPs (deoxyneucleotides) DNA primers Taq polymerase (stable at high temps) Helicase - An enzyme that untwists the double helix of DNA at the replication forks. Ligase - An enzyme that connects two fragments of DNA to make a single fragment Repair for damage to bases from harmful molecules (like chemicals) - Base excision (removes damaged base and replaces it) Mismatch repair - Repair for base mismatches due to errors in replication Repair for double stranded breaks in DNA (Radiation/x-rays) - Homologous recombination (using sister chromosome as model) Non homologous end joining (no model available) Nucleotide excision - Repair for damage from UV which causes adjacent nucleotides to fuse together (thiamine dimers) Amino acid sequence wraps around proteins called - Histones Histones organize to form - Nucleosomes Nucleosomes organize to form - Chromatin Chromatin organizes to form - A chromosome Complete dominance - When the phenotypes of the heterozygote and dominant homozygote are indistinguishable. Codominance - A condition in which neither of two alleles of a gene is dominant or recessive. Both phenotypes are expressed. Incomplete dominance - when the phenotypes of the two alleles blend Point mutations - chemical changes in just one base pair of a gene frameshift mutations - Insertions and deletions 4 parts of an amino acid - Carboxyl group Alpha carbon Amino group R side chain COO- I H - C - R I NH3+ - Abbreviated structure (amino acid) 3 types of amino acids - Hydrophobic Polar Charged Bonds in hydrophobic amino acids - C-C, C-H Bonds in polar amino acids - O-H N-H S-H