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Lecture

Cell Surface and Envelope: Microscopy and Cell Wall Structure

In course

ENV-103: Biology

This course will cover the fundamental principles governing life and the living world. Topics will include the diversity of living organisms, cellular biology, genetics, evolution, and ecology. This course provides a foundation in biology, fostering critic ...

Description

This lecture covers the evolution of microscopy, the structure of cell surfaces, and the composition of cell walls in prokaryotes and archaea. It explores the techniques of gram staining, the role of surface structures like fimbriae and pili, and the functions of different membrane components. The instructor discusses the importance of the S-layer protein and presents examples of research on bacterial walls. Emphasis is placed on the structure of peptidoglycan, the composition of membranes in bacteria and archaea, and the roles of membrane-associated proteins.

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Instructors (4)

Pierre Rossi

Anna Carratala Ripolles

During my PhD, I mainly focused on characterizing the effect of environmental factors (namely temperature and sunlight) and disinfectants on the stability of human viral pathogens as contaminants of aquatic environments. In addition,I developed a novel source tracking tool to identify avian fecal contamination in environmental samples. Thanks to a research fellowship given by the Spanish Ministry of Science and Technology, I also had the opportunity to explore the diversity of marine viruses in Mediterranean coastal waters by genetic fingerprinting and by next generation sequencing. Later on, I became interested in the long-term effect of environmental stressors on virus communities, so I joined the LCE as a postdoc to investigate the adaptation of enteroviruses to ultraviolet radiation. For 4 years, I worked on developing UV-resistant viruses and characterizing their acquired phenotypic and genetic properties by combining directed evolution experiments, deep sequencing and population genetics. Out of the lab, I am passionate about nature, traveling and scuba diving.

Julien Maillard

2011 - present: Research associate at the Laboratory for Environmental Biotechnology (LBE, IIE-ENAC, EPFL) 2007 - 2010: Postdoctoral Fellow at the Laboratory for Environmental Biotechnology (LBE, IIE-ENAC, EPFL) 2005 - 2006: Postdoctoral Fellow at the University of East Anglia (UEA, Norwich, UK) 2000 - 2004: PhD thesis at the Laboratory for Environmental Biotechnology (LBE) 1995 - 2000: B.sc & M.sc at the Swiss Federal Institute for Technology, Zurich (ETHZ)

Ianina Altshuler

Official source

Related concepts (32)

Cell membrane

The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures.

Cell wall

A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters.

Bacterial cell structure

The bacterium, despite its simplicity, contains a well-developed cell structure which is responsible for some of its unique biological structures and pathogenicity. Many structural features are unique to bacteria and are not found among archaea or eukaryotes. Because of the simplicity of bacteria relative to larger organisms and the ease with which they can be manipulated experimentally, the cell structure of bacteria has been well studied, revealing many biochemical principles that have been subsequently applied to other organisms.

Cell (biology)

The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane, and contains many macromolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites. The term comes from the Latin word cellula meaning 'small room'. Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell.

Marine prokaryotes

Marine prokaryotes are marine bacteria and marine archaea. They are defined by their habitat as prokaryotes that live in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. All cellular life forms can be divided into prokaryotes and eukaryotes. Eukaryotes are organisms whose cells have a nucleus enclosed within membranes, whereas prokaryotes are the organisms that do not have a nucleus enclosed within a membrane.

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