Question

The process of DNA replication involves a variety of enzymes that interact in complicated ways. Not frames in a film represent different stages in its progression. 1. Suppose that a replication fork has been initiated and is moving to the right. Draw a diagram illustrating the template molecules and the newly synthesized molecules at a particular moment in time. Be sure to differentiate between these two types of molecules as well as between deoxyribo- and ribonucleic acids. Be sure also to indicate the end-to-end orientation of each molecule. 2. Suppose now that a short time has passed and the replication fork has moved a bit further to the right. Draw a new illustration to show what has changed. 5', polymerase activity. How would you change 3. Suppose that DNA polymerase I has a second, 3' your diagrams?

Answer 1

1. Figure below shows initiation of replication fork, blue strands are template and red strands are newly synthesized molecules. Position of DNA polymerase is shown in black shaded structure. Portion of template-newly synthesized molecule junction is shown by enlarged diagram, where deoxyribonucleic acids are shown.

ما m Newly synthesized molecule اي لمہ کے هكهكهكهكهكملک بل Template molecule

2. Replication fork after some time, showing leading (continuous) strand and lagging (discontinuous) strands with okazaki fragments.

3. Replication fork after the action of DNA ploymerase I,showing filled gaps (in blue among the red newly synthesized strand). Direction of replication and gap filling are indicated by arrows.