Biochemistry: Concepts and Connections (2nd Edition)
2nd Edition
ISBN: 9780134641621
Author: Dean R. Appling, Spencer J. Anthony-Cahill, Christopher K. Mathews
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 22, Problem 6P
The E. coli chromosome is 1.28 mm long. Under optimal conditions, the chromosome is replicated in 40 minutes.
- What is the distance traversed by one replication fork in 1 minute?
- If replicating DNA is in the B form (10.4 base pairs per turn), how many
nucleotides are incorporated in 1 minute in one replication fork? - If cultured human cells (such as HeLa cells) replicate 1.2 m of DNA during a five-hour S phase and at a rate of fork movement one-tenth of that seen in E. coli, how many origins of replication must the cells contain?
- What is the average distance, in kilobase pairs, between these origins?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Approximately how many high-energy bonds does DNA polymerase use to replicate a bacterial chromosome (ignoring helicase and other enzymes associated with the replication fork)? compared with its own dry weight of 10–12 g, how much glucose does a single bacterium need to provide enough energy to copy its DNA once?
The E. coli chromosome is 1.28 mm long. Under optimal conditions, thechromosome is replicated in 40 minutes.(a) What is the distance traversed by one replication fork in 1 minute?(b) If replicating DNA is in the B form (10.4 base pairs per turn), how manynucleotides are incorporated in 1 minute in one replication fork?(c) If cultured human cells (such as HeLa cells) replicate 1.2 m of DNAduring a five-hour S phase and at a rate of fork movement one-tenthof that seen in E. coli, how many origins of replication must the cellscontain?(d) What is the average distance, in kilobase pairs, between these origins?
The chromosome of E. coli contains 4.6 million bp. How long will it take to replicate its DNA? Assuming that DNA polymerase III is the primary enzyme involved and that it can actively proofread during DNA synthesis, how many base pair mistakes will be made in one round of DNA replication in a bacterial population containing 1000 bacteria?
Chapter 22 Solutions
Biochemistry: Concepts and Connections (2nd Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biochemistry and related others by exploring similar questions and additional content below.Similar questions
- You decide to repeat the Meselson-Stahl experiment, except this time you plan to grow the E. coli cells on light 14N medium for many generations and then transfer them to heavy 15N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication). If the conservative model of DNA replication was correct, what is the expected distribution of DNA in the density gradient after two rounds of replication? Multiple Choice One band of intermediate density. One band of light density. One band of heavy density. One band of light density and one band of heavy density. One band of light density and one band of intermediate density.arrow_forwardA bacterium synthesizes DNA at each replication fork at a rate of 1500 nucleotides per second. If this bacterium completely replicates its circular chromosome by theta replication in 20 minutes, how many base pairs of DNA will its chromosome contain?arrow_forwardSuppose that E. coli synthesizes DNA at a rate of 100,000 nucleotides per minute and takes 40 minutes to replicate its chromosome. (a) How many base pairs are present in the entire E. coli chromosome? (b) What is the physical length of the chromosome in its helical configuration—that is, what is the circumference of the chromosome if it were opened into a circle?arrow_forward
- E. coli chromosomes in which every nitrogen atom is labeled (that is, every nitrogen atom is the heavy isotope 15N instead of the normal isotope 14N) are allowed to replicate in an environment in which all the nitrogen is 14N. Using a solid line to represent a heavy polynucleotide chain and a dashed line for a light chain, sketch each of the following descriptions:a. The heavy parental chromosome and the products of the first replication after transfer to a 14N medium, assuming that the chromosome is one DNA double helix and that replication is semiconservative.b. Repeat part a, but now assume that replication is conservative.c. If the daughter chromosomes from the first division in 14N are spun in a cesium chloride density gradient and a single band is obtained, which of the possibilities in parts a and b can be ruled out? Reconsider the Meselson and Stahl experiment: What does it prove?arrow_forwardUsing 14N isotope medium for DNA replication instead of 15N, what would be observed ifDNA replication were conservative in one cycle of replication/in three cycles? How aboutdispersive replication in one cycle, in three cycles?arrow_forwardA circular molecule of DNA contains 1 million base pairs. If the rate of DNA synthesis at a replication fork is 100,000 nucleotides per minute, how much time will theta replication require to completely replicate the molecule, assuming that theta replication is bidirectional? How long will replication of this circular chromosome by rolling-circle replication take? Ignore replication of the displaced strand in rolling-circle replication.arrow_forward
- The following DNAs were incubated with E. coli DNA Polymerase I and dNTPs. Write the products expected in each reaction. Indicate the activity used in each reaction.arrow_forwardUsing the same experimental setup as in the original Meselson and Stahl experiment, predict the bands (heavy, light or intermediate) that you would observe after one round of replication if DNA polymerase replicated the bacterial genome by the conservative model of replication. Draw and explain your prediction.arrow_forwardIn the Meselson-Stahl experiment on DNA replication, what fraction of the DNA was composed of one light strand and one heavy strand ("hybrid") after one generation of growth in medium containing 14N? After two generations of growth in a medium containing 14N? What fraction of hybrid DNA is expected after n generations of growth in a medium containing 14N?arrow_forward
- It takes 40 minutes to completely replicate the E. coli chromosome, even in an optimally nourished cell. However, bacterial cells can divide as frequently as every 20 minutes. How can cells divide more rapidly, apparently, than their DNA can be copied?arrow_forwardThe Meselson-Stahl experiment provided strong evidence that DNA replication was conservative, by alternately growing bacteria in medium with heavy 15N and light 14N. If DNA replication were dispersive, what result would Meselson and Stahl have observed after the first round of DNA replication in light nitrogen? Group of answer choices Two bands, one at the location for pure 15N and one at the location for pure 14N. One band, located half way between the locations for pure 15N and pure 14N. Two bands, one at the location for pure 15N and one located halfway between the locations for pure 15N and pure 14N. None of these Three bands, one at the location for pure 15N, one at the location for pure 14N, and one at a location halfway between.arrow_forwardA mixture of four a-[32P]–labeled ribonucleoside triphosphates was added to permeabilized bacterial cells undergoing DNA replication in the presence of an RNA polymerase inhibitor, and incorporation into high-molecular-weight material was followed over time, as shown in the accompanying graph. After 10 minutes of incubation, a 1000-fold excess of unlabeled ribonucleoside triphosphates was added, with the results shown in the graph. (a) Why was the excess of unlabeled rNTPs added?(b) How could you tell that radioactivity is being incorporated as ribonucleotides rather than as an alternative such as reduction to deoxyribonucleotides, followed by incorporation?(c) What does this experiment tell you about the process of DNA replication?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
QCE Biology: Introduction to Gene Expression; Author: Atomi;https://www.youtube.com/watch?v=a7hydUtCIJk;License: Standard YouTube License, CC-BY