WGU Biochemistry OA 2022/2023 Questions With Answers

in the organization of DNA into chromosomes, DNA is wrapped around ______ to form nucleosomes. nucleosomes are organized further to form ______ Ans - histones chromatin what would lead to disease due to change in protein structure Ans - interactions within primary protein structure Ans - sequence of amino acids held together by peptide bonds interactions within secondary structure Ans - formation of hydrogen bonds bonds occur between the backbone, it doesn't affect the type of amino acid interactions within quaternary structure Ans - interaction between polypeptide chains occur between different sub units (two different amino acids) interaction within tertiary structure Ans - makes R groups come together creating the 3 dimensional shape.. base excision repair Ans - damage to a single base pair (nucleotide) nucleotide excision repair Ans - removes multiple nucleotides (20-30) caused by UV exposure mismatch Ans - mistake was made during replication. homologous recombination Ans - repairs double strand breaks using homology due to radiation and xray nonhomologous end joining Ans - A quick-and-dirty mechanism for repairing double-strand breaks in DNA that involves quickly bringing together, trimming, and rejoining the two broken ends; results in a loss of information at the site of repair. does not take homology in to account steps for repairing damage to sequence pathways Ans - recognize damage- - remove damaged area-- resynthesize sequence-- ligate backbone normal NER pathway Ans - uv light thymine dimers form damage repaired cell cycle is unaffected defective NER pathway Ans - uv light thymine dimers form damage isn't repaired mutations accumulate probability of developing cancer increases type of DNA damage affected: DNA polymerase is mutated and cannot fill in the gap after repair enzymes remove damaged nucleotides Ans - single damaged base thymine dimers type of DNA damage affected: mutated DNA repair enzymes in nucleotide excision repair do not recognize damaged regions of DNA Ans - thymine dimers type of DNA damage affected: mutation in DNA polymerase prevents it from recognizing an incorrectly added base during DNA replication Ans - mismatch type of DNA damage affected: mutation in the recombination machinery involved in DNA repair Ans - double stranded break