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DNA ligase - joins two DNA fragments together by forming phosphodiester bonds between the two fragments - VCE - SSCE Biology - Question 38 - 2019 - Paper 1
Question 38
DNA ligase - joins two DNA fragments together by forming phosphodiester bonds between the two fragments. - acts as molecular scissors, cutting DNA molecules at spec... show full transcript
Worked Solution & Example Answer:DNA ligase - joins two DNA fragments together by forming phosphodiester bonds between the two fragments - VCE - SSCE Biology - Question 38 - 2019 - Paper 1
Step 1
joins two DNA fragments together by forming phosphodiester bonds between the two fragments.
Answer
DNA ligase facilitates the joining of DNA fragments by creating phosphodiester bonds, which are essential for the integrity of the DNA structure. This process is critical during DNA replication and repair, allowing the DNA backbone to be seamlessly connected.
Step 2
acts as molecular scissors, cutting DNA molecules at specific nucleotide sequences.
Answer
While DNA ligase does not act as molecular scissors, this role is more accurately attributed to enzymes such as restriction endonucleases. These enzymes cut DNA molecules at defined sequences, allowing for the removal of segments or the insertion of new DNA fragments during genetic engineering.
Step 3
separates two DNA strands during transcription so that a copy can be made.
Answer
DNA ligase is not responsible for unwinding the DNA strands during transcription. Instead, this process is carried out by the enzyme helicase, which unwinds the DNA helix, allowing transcription to occur. DNA ligase's primary function is to join DNA fragments post-replication or repair.
Step 4
is an enzyme involved in protein synthesis.
Answer
DNA ligase is not directly involved in protein synthesis. Protein synthesis primarily involves mRNA, ribosomes, and various transfer RNAs (tRNAs). While DNA ligase plays a crucial role in DNA replication and repair, its function is separate from the processes of transcription and translation, which are essential for protein synthesis.