Ans c) 3' hydroxyl of deoxyribose.
During elongation phase of DNA replication, DNA polymerase adds new nucleotides to the 3' OH of the growing strand with the replication progressing in 5' to 3' direction. The nucleotide has a phosphate group, a ribose/ deoxyribose sugar, and a nitrogenous base. The phosphate group is attached to the 5' position of the deoxyribose sugar while its 3' position is occupied by the hydroxyl group. The motive behind the incorporation of new nucleotide always at 3' OH end of growing DNA chain is the nucleophilic approach used by 3' OH attacking the phosphorous atom of incoming dNTPs and simultaneously a phosphodiester bond is formed with the release of inorganic pyrophosphate. Mg ion, in turn, helps in minimizing the interaction between the O and the H, leaving a nucleophile 3'O- . Since 3' hydroxyl group is a better nucleophile as compared to others this explains the addition of new nucleotide here. One more reaction that is essential for DNA replication, the pyrophosphate hydrolysis is easily accomplished in this way.
When enzymes are elongating (building) a newly synthesized DNA strand in PCR, new nucleotides are being...
DNA is formed by building blocks called __________. nucleotides nitrogenous bases polypeptides deoxyribose 0.5 points QUESTION 2 What does DNA stand for? Double-stranded Nucleic Acid Ribonucleic acid Deoxyribonucleic Acid Double-helix Nucleic Acid 0.5 points QUESTION 3 The nucleotides of DNA are held together by ___________. ionic bond hydrogen bond phosphodiester bond sugar-phosphate backbone 0.5 points QUESTION 4 DNA nucleotides with one-carbon nitrogen ring bases are called ________. adenines purines pyrimidines guanines 0.5 points QUESTION 5 Basic...
DNA mismatch repair enzymes preferentially repair bases on the newly synthesized DNA strand, using the old DNA strand as the template. If mismatches were simply repaired without regard for which strand served as template, would this reduce replication errors? Explain your answer (5 pts) Describe DNA replication (remember to mention all the enzymes involved) (10 pts)
21. In DNA replication, new nucleotides are added a. To the 5' end of each nascent strand b. To the 3'end of each nascent strand To both ends of each nascent strand d. To the 5' end of the continuous strand and the 3' end of the discontinuous strand e. To the end of the continuous strand and the end of discontinuous strand fragments 22. DNA unwinding is done by a. Ligase b. Helicase c. Topoisomerase dHexonuclease 23. Proofreading of...
The enzymes that initiates synthesis of a new DNA strand is called _________. The name given to the short segments of RNA that is added at the beginning of all newly synthesized DNA strands is called _________.
QUESTION 5 The enzymes that connect nucleotides to the growing end of a new DNA strand are called O Toposiomerases O Helicases polymerases Nucleases O Primase
To incorporate radiolabeled nucleotides into newly synthesized DNA, researchers use α-phosphorus32-labeled nucleotides, in a DNA synthesis reaction, where the α denotes the position of the radioactive phosphate moiety. Explain why the α position--rather than the β or γ positions--is the best position for the radioactive group in these experiments.
When a dideoxynucleotide is incorporated into one new strand by DNA polymerase, 1.addition of nucleotides to all new strands stop. 2.addition of nucleotides only to that strand ceases. 3.nothing changes. 4.addition of nucleotides only to that strand speeds up. 5.nucleotides are removed only from that strand and then new nucleotides are added.
RNA differs from DNA in that it: all of the above contains ribose sugar contains uracil is usually found as a single-stranded molecule in cells Question 21 pts The correct order of steps in a PCR cycle is: Extension, denaturation, annealing Annealing, extension, denaturation Annealing, denaturation, extension Denaturation, annealing, extension The goal of the polymerase chain reaction (PCR) is to: Amplify a small amount of DNA sequence Cleave DNA molecules Digest bacterial plasmids Sequence DNA Which of the following is...
34. DNA polymerase A. adds nucleotides to the leading strand of DNA B. removes RNA from the lagging strand C. unwinds the DNA during duplication D. cuts DNA at specific sites to relieve mechanical tension E. is not used in eukaryotic cells 35. Radioactive thymidine added to a cell will bind to A. DNA that is being synthesized B. mRNA that is being synthesized C. RNA that is being synthesized D. miRNA that is being synthesized E. all of the...
Question 1: In DNA, which of the following functional groups plays a key role in polymerization (covalent linkage of the monomer nucleotides)? A. phosphate B. methyl C. sulfhydryl D. hydrogen E. nitrogen Question 2. The named components of a nucleotide of RNA are A. ribose, phosphate, A,U,G or C base B. deoxyribose, phosphate, A, T, G or C base C. deoxyribose, phosphate, A, U, G, or C base D. ribose, phosphate, A, T, G or C base Question 3. In...