Molecular glue or gum is

Options

A. DNAase
B. DNA polymerase
C. DNA ligase
D. DNA dependent RNA polymerase

Answer

To solve the question "Molecular glue or gum is," we need to analyze the given options and determine which enzyme is referred to as "molecular glue." Here’s a step-by-step solution:

### Step 1: Understand the Question
The question asks for the enzyme that is commonly known as "molecular glue" or "gum."

### Step 2: Analyze the Options
We have four options to consider:
1. DNA polymerase
2. DNA ligase
3. DNA-dependent RNA polymerase
4. DNA ribonuclease

### Step 3: Define Each Option
- **DNA polymerase**: This enzyme is responsible for synthesizing new DNA strands by adding nucleotides to a growing DNA chain during DNA replication.
- **DNA ligase**: This enzyme plays a crucial role in joining DNA strands together. It is essential for sealing nicks in the DNA backbone, especially during DNA replication and repair.
- **DNA-dependent RNA polymerase**: This enzyme synthesizes RNA from a DNA template during the process of transcription.
- **DNA ribonuclease**: This enzyme degrades RNA by catalyzing the hydrolytic cleavage of the RNA backbone.

### Step 4: Identify the Correct Answer
Among the options, **DNA ligase** is known as "molecular glue" because it connects DNA fragments by forming phosphodiester bonds, effectively sealing breaks in the DNA strands. This function is critical during DNA replication and repair processes.

### Step 5: Conclusion
The correct answer to the question "Molecular glue or gum is" is **DNA ligase**.