Cells are the basic structural and functional unit of all life on Earth.
This lecture reviews the basic building blocks of cells, the main
chemical components, the two basic types of cells (Prokaryotes and
Eukaryotes), and introduces the Phylogenetic Tree of Life, the way
biologists order life by their biochemical and genetic relationships.
Understanding lif ... Show More
Oct 2009
Lecture 15: The Chemistry of Life
What is the basic chemistry of living organisms? We introduce the requirements for metabolism (raw materials and energy), the ATP/ADP energy cycle in cells, auto- and heterotrophs, photosynthesis and chemosynthesis, and the role played by liquid water. The goal of today's lecture ... Show More
45m 4s
Oct 2009
Lecture 17: Life on the Edge
Extremophiles are organisms that are adapted to survive in extreme environments. This lecture describes the challenges that extremes of heat, cold, acidity, salinity, and radiation pose to organisms, and show examples of how evolution has nonetheless allowed some organisms to ada ... Show More
46m 54s
<p>La durée de vie d'une étoile peut nous renseigner sur sa composition et sur l'existence éventuelle de la vie dans le cosmos. mais, en dehors du Soleil, il est assez difficile de déterminer l'âge d'une étoile.</p><br><p>L'importance de la masse</p><br><p>En évaluant, grâce à la ... Show More
