Molecular Biology B


The main objective of the course of Molecular Biology B is to present the macromolecules that are essential to life processes with focus on the processes of replication, transcription and translation.

Students will be exposed to a generalist introduction of the different macromolecules that ensure viability of a cell (bacterium or eukaryotic cell) with a special attention to the molecular processes that allow the transmission and interpretation of hereditary information. The different processes will be detailed so that students are able to identify several components that perform different functions in each molecular process.

After attending this course students should be able to:

  • Identify the different components that are found in different cell types.
  • Describe how the DNA molecule was identified as a determinant for hereditary information.
  • Identify the chemical composition of the DNA molecule, its structure and its organization within a cell.
  • Describe the DNA replication process, the mechanisms that ensure the reliability of this process and how the different elements can be used in the laboratory.
  • Describe the process by which the information encoded in the DNA molecule is converted into mRNA (transcription) and protein (translation).
  • Identify mechanisms that ensure the regulation of gene expression.

General characterization





Responsible teacher

Sérgio Joaquim Raposo Filipe


Weekly - 4

Total - 53

Teaching language





Molecular Biology of the Cell; Alberts et al. ; 6th ed. (2015). Garland Science.

Biologia Celular e Molecular; C. Azevedo, C. E.; 5th ed. (2012). Lidel, Porto.

Molecular Cell Biology; Lodish et al.; 8th ed. (2016). W. H. Freeman

Molecular Biology of Assemblies and Machines; Steven et al.; 1st ed. (2016) Garland Science

Internet pages of scientific associations with contents taught

Teaching method

Theoretical classes with slides for presentation of contents, solving and/or discussing problems.

Practical classes to execute experimental protocols, analysis and interpretation of experimental results and oral presentations.

Access to contents in the Moodle page with exercises and presentations about the contents that are taught.

Evaluation method

The evaluation will have two components:

- a theoretical-practical evaluation with two written tests with questions about the contents taught in the theoretical classes and practical classes (80% of the final classification) and calculated to two decimal places and an equal weight in the final grade of this evaluation component.

- a summative and laboratory assessment component, determined through a continuous student assessment process in the laboratory. This evaluation, with a classification carried out with two decimal places by the lecturer of the practical class, will be associated with the work carried out by the students, during the practical class and in autonomy, and in the presentation of small elements of evaluation, submitted in Moodle, where students summarize what they have done and what they have learned while attending practical classes associated with each assignment or carrying out procedures requested by the teacher (20% of the final grade, 4/20 out of 20).


Subject matter

The course program includes the following topics:

  1. Molecular components of cells and their functions.
  2. Experiments that demonstrated how DNA is responsible for heredity.
  3. Structure and chemical composition of different nucleic acids found within a cell.
  4. Characterization of the DNA present in a cell (composition, organization and packaging).
  5. Mechanisms used for the high-fidelity propagation of DNA (replication).
  6. DNA modification and mutagenesis processes.
  7. Mechanisms of recombination and repair of the DNA molecule.
  8. Processes that allow cells to read information encoded their genome: (1) from DNA to RNA (transcription); (2) RNA for protein (translation).
  9. Control of gene expression.

The protocols performed in the laboratory include:

  1. Propagation of bacterial cells in liquid culture media.
  2. Isolation, purification and quantification of nucleic acids.
  3. Quantification and purity analysis of a DNA sample by UV spectrophotometry.
  4. Enzymatic hydrolysis of plasmid DNA and analysis of the resulting fragments by agarose gel electrophoresis.
  5. Amplification of DNA fragments by PCR.
  6. Regulation of genetic expression: evaluation of the activation of the Lac operon.