Biochemistry WGU Exam Questions And Answers

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