ASCP Molecular Biology Certification Exam 2024 100% Correct

ASCP Molecular Biology Certification Exam 2024 Pyrimidine - Answer ️️ -One carbon ring Cytosine, Thymine, Uracil Purine - Answer ️️ -Two carbon rings Adenine, Guanine How are nucleotides joined together? - Answer ️️ -Condensation to form phosphodiester bond What is the function of mRNA? - Answer ️️ -Carries genetic info out of nucleus Transcript translated to protein What is the function of tRNA? - Answer ️️ -Carries aa to ribosome Anticodon pairs with codon on mRNA strand What is the function of rRNA? - Answer ️️ -part of ribosome structure most abundant RNA coordinated coupling of tRNA to mRNA codons Feedback inhibition - Answer ️️ -Product of pathway is noncompetitive inhibitor Binds to allosteric site to slow down rxn b/c too much product Exonucleases - Answer ️️ -Degrades nucleic acids by removing one terminal nt at a time Cleaves phosphodiester bond at end of chain 5' --> 3' and 3' --> 5' Endonucleases (Prok) - Answer ️️ -Restriction enzymes Cleaves phoshpodiester bonds w/i poly-nt chain Recognition site is palindromic sequence Types I-V ORI sites - Answer ️️ -nt sequence where replication is initiated Topoisomerase I - Answer ️️ -Induces ss breaks Remove DNA supercoils during TXN and DNA replication; for strand breakage during recombination; for chr condensation; and to disentangle intertwined DNA during mitosis topoisomerase II - Answer ️️ -cuts both strands of one DNA double helix, passes another unbroken DNA helix through it, and then reanneals the cut strands Gyrase (topoisomerase II) - Answer ️️ -Unwinds supercoiling caused by unwinding at the rep fork by introducing DSBs Helicase - Answer ️️ -Breaks H-bonds of double helix at the replication fork Primase - Answer ️️ -DNApol α (DNA dep RNA pol) adds short segments of complementary RNA to ssDNA template (primers), serves as starting points for replication single-strand DNA binding proteins (SSBPs) - Answer ️️ -Binds ssDNA and prevents it from re-annealing during TXN, replication, repair, and recombination Okazaki fragments - Answer ️️ -Short fragments of DNA synthesized by DNApol δ using the lagging strand (3'->5') as a template Ligase - Answer ️️ -Closes gaps in DNA Catalyzes phosphodiester bond between 3'OH and 5'P What are the steps in DNA replication? - Answer ️️ -1. Initiate 2. Elongate 3. Terminate Telomeres - Answer ️️ -Repeat sequence (TTAGGG) at the ends of chr, protect chr from degradation RNA polymerase - Answer ️️ -DNA dependent RNApol Transcribes DNA template to RNA (3'-->5'; anti-parallel) Splicesomes - Answer ️️ -Complex of snRNPs Removes introns from pre-mRNA and splices exons together Enhancers - Answer ️️ -Short regions of DNA that bind proteins (TXN factors) that enhance TXN of a gene Poly-A tail - Answer ️️ -Prevents mRNA from being degraded in cytoplasm 100-250 A's at 3' end 5' cap - Answer ️️ -5'-5' pyrophosphate bridge to a methylated G added to 5' end of a mRNA Protects against degradation and as a recognition signal for TLN ap