The Cardiovascular System


Key Functions

  • → Transportation of nutrients (O2
  • → Thermoregulation


Primary Function

Secondary Functions


What is covered in this Lesson

    1. Central Dogma of Biology
    2. Transcription 
    3. Translation

By the end of this lesson you should be able to:

    1. Explain the flow of biological information  genetics to proteins. 
    2. Describe the process of transcription include that proteins and molecules are involved. 
    3. Outline what happens in each of the three stages of protein translation.  
Title: Drawing of the Eye | Author: National Human Genome Research Institute

Central Dogma of DNA


Making Connections 

Deviations from the simple scheme of the central dogma can be found in nature. For example the human immunodeficiency virus (HIV) is a retrovirus which mean it stores its genetic information in single stranded RNA molecules. Upon infection of a host cell, RNA is used as a template by the virally encoded enzyme, reverse transcriptase, to synthesize DNA. The viral DNA is incorporated into the host cell’s genome. Later it is  transcribed into mRNA and then translated into proteins. Some RNA viruses such as the influenza virus never go through a DNA step. The RNA genome is replicated by an RNA dependent RNA polymerase which is virally encoded.


Transcription: Copying DNA to RNA

Translation: Turning mRNA into Protein





  1. Fowler, S, Roush R, and Wise J. “Molecular Biology.” Concepts of Biology. Houston, TX: OpenStax, CC BY 4.0 License TermsEdited & Adapted | Access for free at
  2. Zedalis, J, and  Eggebrecht, J. “3.5 Nucleic Acids.” Biology for AP® Courses, p. OpenStax, TermsEdited & Adapted | Access for free at