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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 plays a crucial role in molecular biology by facilitating the joining of two DNA fragments. This process occurs through the formation of phosphodiester bonds, which are covalent bonds between the 3′ hydroxyl group of one nucleotide and the 5′ phosphate group of another, ultimately linking the fragments together securely.
Step 2
acts as molecular scissors, cutting DNA molecules at specific nucleotide sequences.
Answer
It's important to note that DNA ligase does not act as molecular scissors; that role is typically associated with other enzymes such as restriction enzymes. DNA ligase functions instead to connect DNA fragments post-cutting, rather than performing the actual cutting.
Step 3
separates two DNA strands during transcription so that a copy can be made.
Answer
The separation of DNA strands during transcription is predominantly the role of RNA polymerase, not DNA ligase. While ligase facilitates the joining of DNA fragments after the transcription and replication processes, it does not separate DNA strands.
Step 4
is an enzyme involved in protein synthesis.
Answer
DNA ligase itself is not directly involved in protein synthesis. Rather, it plays a role in DNA replication and repair, which are critical processes that precede protein synthesis. The actual synthesis of proteins involves ribosomes and messenger RNA, translating genetic information into polypeptide chains.