Transcription chain elongation is thought to generate supercoils ahead of the transcription bubble and supercoils behind it. a. positive; negative b. negative; positive c. negative; negative d. positive; positive e. none of the above

a. positive; negative

Explanation:

Transcription is the process of forming an RNA molecule from a DNA template molecule. In this process, the strands of DNA separate and one serves as a template for RNA, while the other is inactive. At the end of the transcript, the tapes that have been split back together again.

The transcription process is divided into three steps: initiation, stretching and termination

During the stretching phase, transcription chain elongation occurs. In this phase the enzyme called RNA polymerase starts to move through the DNA molecule, unwinding its helix and producing an increasingly lengthened RNA molecule. The already transcribed DNA is rewound almost immediately, recomposing its double helix. This process is called the elongation phase.

During this process, it is believed that positive supercoils  are generated ahead of the transcription bubble and  and the negative supercoils behind it.

the binding of the substrate is dictated by the shape of each molecule. side chains on the enzyme interact with the substrate in a specific way, resulting in the making and breaking of bonds.