Question

Question 2 [10] Tabulate the main differences between prokaryotic and eukaryotic replication. Question 3 [10] Describe the basic principle governing Meselson and Stahl's experiment. What would the results of Meselson and Stahl have looked like if DNA replication were conservative? And what would it have looked like if DNA replication were dispersive? [8] Question 4 Describe in detail the structure of tRNA and its function in translation Question 5 [20] 5.1 List the two types of transcription termination mechanisms that occur in prokaryotes and discuss them in detail. (10) 5.2 Briefly discuss the post-transcriptional modifications that occur in eukaryotic RNA molecules (10) (14) Question 6 6.1 Write a brief summary of negative control in the lac operon, noting the key points. Include a diagram to support your answer. (10) 6.2 Explain how CAMP helps to regulate the lac operon (4)

biochemistry

Answer 1

Prokaryotic replication Eukaryotic replication prokaryotic DNA replication is the process by which a prokaryotic organism duplicates its entire genome in order to pass the second copy to a daughter cell eukaryotic DNA replication is the process by which the eukaryotic genome duplicates prior to cell division takes place in cytoplasm takes place in the nucleus DNA is circular and double stranded DNA is linear and double stranded with ends a continuous process occurs during s phase of the cycle there is a small amount of prokaryotic DNA 50 times more than that of prokaryotic DNA only one replication fork is formed multiple replication forks are formed simultaneously in each chromosome only have one origin of replication has multiple origins of replication replication occurs at point in each chromosome replication occurs at several points simultaneously in each chromosome replication is faster replication is slower compared to prokaryotics DNA gyrase is needed DNA gyrase is not needed final product is two circular chromosome final product is two sister chromatids