Not all the genes in your body are turned on at the same time or in the same cells or parts of the body.įor many genes, transcription is the key on/off control point: if a gene is not transcribed in a cell, it can’t be used to make a protein in that cell. Gene expression is when a gene in DNA is “turned on,” that is, used to make the protein it specifies. There are many steps along the way of protein synthesis and gene expression is regulated. Basically, there are proteins that have to bind to the DNA, and each other, before the polymerase can begin transcription. The overview above depicted components of transcription regulation. Transcription is happening throughout your body all of the time, but not every gene is constantly being transcribed in every cell it is regulated by different proteins and depends on which proteins your body needs in which cells.

By “regulation”, we mean that certain proteins are needed for transcription to start and some proteins can even prevent transcription from happening. At the beginning of the following video, you will see that transcription is regulated by a variety of proteins. Let’s first look at a basic overview of what the process of transcription looks like. The Process of Transcription: A First Look

Transcription is the process of creating an mRNA sequence by “reading” the DNA sequence. Please see the previous chapter for a general overview of transcription and DNA and RNA bases before continuing to read this chapter. This chapter focuses on how transcription works that is, how information coded in the DNA molecule is read to create an mRNA sequence.

Explain which gene-expression regulatory factors are at play for transcription.

Recognize that protein synthesis regulation (i.e., changes in gene expression) allow cells to respond to changes in the environment.

Describe the role of polymerase in transcription.

Explain how DNA is transcribed to create an mRNA sequence.

Explain the processes necessary for transcription to begin.

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