3.3 DNA replication rates time evoluti after additic An operon i unit. Use the e

Question

3.3 DNA replication rates

time evoluti after additic An operon i unit. Use the elongation morphology point for tra (c) Using th frequency o are among t (d) As we sa division tim Assuming th RNA polym any instant? molecules i genes? replication forks 3.5 Cell Read the pa Salmonela direction (Blochim. Bi of fork movement (a) The auth assumption is proportio out the nees protein, in a the total pre the number non-ribosor needed per assumption protein con 0.1 Figure 3.35: Replication forks in D, melanogaster. Replication maximum g forks move away in both directions from replication origins (Electron micrograph courtesy of Victoria Foe. Adapted from (b) With a3 protein is ri et al., Molecular Biology of the Cell, 5th ed. Garland ty phimuriun these numb Science, 2008.) 3.3 DNA replication rates of the prote rate studie

Explanation / Answer

a). We can measure the length of the picture and conclude that this genome is roughly 1.4µm. Now we can change it into nm

1 µm=1000

1.4x1000=1400

No. of base pair=1400nm/0.34nm per bp=4000base pairs

the fraction of the total fly genome is roughly=4000/2x108bp=2x10-5

B). Estimate the number of DNA polymerase molecules in a eukaryotic cell like this one from the fly D. melanogaster.

Let that all the DNA polymerase molecules are found in the bounded form with the DNA at the time of replication. The figure shows 8 DNA polymerase molecules (one in each fork)

No. of DNA polymerase molecules= 8x2x108bp/4000=4x105

C). There are eight forks in the micrograph. Estimate the lengths of the DNA strands between replication forks 4 and 5, counting up from the bottom of the figure. If a replication fork moves at a speed of roughly 40 bp/s, how long will it take for forks 4 and 5 to collide?

Here the approximate distance between forks 4 & 5 is 200nm or 0.2 µm (600bp).

If the DNA polymerase is move at a speed of approximately 100bp/s, it means it takes 3 seconds for each fork to collide.

d) The given picture the stage of the replication is in its development, and each cell cycle time takes ten minutes that’s why all the cells are replicate and divide very quickly. The density of replication forks is constant and the rate of the replication is 100 nt/s, So that the replication time has a time scale of approximately five seconds.

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.