What is a Chromosome? A chromosome is a long, continuous strand of DNA that contains many genes. Genes function as the basic unit of heredity in living cells, coding for various proteins. Each gene is located at a specific position on the chromosome, known as its locus. Chromosomes also contain non-coding regions of DNA, which […]
Unlike prokaryotes, eukaryotes must process mRNAs before they can be translated into proteins. The primary mRNA transcript is first made by transcription of the DNA by RNA pol II. The transcript contains both introns and exons, hence it is called heterogenous RNA (hRNA). The 5′ end of the hRNA is capped and a polyA tail […]
In prokaryotic cells the focus of the regulation of gene expression is almost entirely at the level of the initiation of transcription. However, in eukaryotic cells, regulation of gene expression can occur at all stages of transcription and translation, and even at protein stability. Opportunities for Gene Regulation in Gene Expression in Eukaryotes Those common […]
Anti-Termination It is possible for prokaryotic RNA polymerase to ignore termination signals and continue to transcribe until a downstream termination signal is reached. This mechanism is used by lambda phage. The lambda N gene codes for pN which interacts with polymerase RNA to enable it to read through to genes further downstream. Another antiterminator called […]
Gene Regulation at Transcriptional Termination In the previous article we saw how RNA polymerase determines how to start transcription. In this article, we will examine how it decides to end transcription. Before we dive in, however, let’s take some time to remind ourselves of the lay of the land. So far, we are well familiar […]
Prokaryotes are able to regulate gene expression by applying unique tricks in their toolbox. In prokaryotic cells, genes expression is regulated almost entirely at the level of the initiation of transcription. In eukaryotic cells, regulation of gene expression can occur at all stages of transcription and translation, and even after a protein is made. I […]
The total energy budget of a prokaryote cell with its 4.6 million nucleotides and 4,288 different genes, is about 10 billion ATP. This is significant. The cell must therefore make sure that this massive expenditure is wisely used by making the right genes at the right time in the right amounts. This article will explain […]
In the next series of articles I will be covering transcription in prokaryotes. I suppose that this is a topic that you have been introduced to in previous biology classes that you have taken. We will get a more in-depth look into the subject. However, before we dive in, let’s review a few basic concepts. […]
Objectives By the end of this lesson you should be able to: This week we will learn the basic principles of biotechnology. In later special topic classes we will see how biotechnology is applied in the real world, including the bioengineering of food, identification of criminals, and finding cure for disease. DNA Extraction and Purification […]
