basal membrane, a sheet of tissue that forms the outer layer of the choroid and lies just under the pigmented layer of the retina. It is composed of elastic fibers in an otherwise thin homogenous layer.asal membrane, a sheet of tissue that forms the outer layer of the choroid and lies just under the pigmented layer of the retina. It is composed of elastic fibers in an otherwise thin homogenous layer.
There are several enzymes that 'unzip' DNA. These enzymes are collectively known as DNA helicases. DNA helicases are helix-destabilizing enzymes that bind to DNA at the origin of replication and break hydrogen bonds, thereby separating the two strands.. Solomon, Eldra P., Linda R. Berg, and Diana W. Martin. Biology. 8th ed. Belmont, CA: Thomson Brooks/Cole, 2008.
Transcription. 1. Transcription: The DNA unwinds and unzips in the area of the gene. A promoter is needed in order to start. Enzymes match RNA nucleotides to the unzipped nitrogen bases of the gene, forming a single strand of mRNA. 2. The strand of mRNA detaches from the gene and goes out of the nucleus through one of the pores in the nuclear envelope. The DNA zips back together and winds back up. 3. The mRNA finds a ribosome where protein synthesis will happen.