This art history video discussion examines Benvenuto Cellini's "Perseus with the Head of Medusa," c. 1554, bronze (Loggia dei Lanzi, Piazza della Signoria, Florence).

Learn about how phospholipids form the cell membrane, and what types of molecules can passively diffuse thorugh the membrane. By William Tsai. . Created by William Tsai.

Learn about the major components that make up our cell membrane and the fluid mosaic model. By William Tsai.

Learn about the different types of proteins that exist on the cell membrane. By William Tsai.

Yeast can reproduce sexually through a signaling pathway known as the mating factor pathway. In this process, two haploid yeast cells combine to form a diploid cell. Yeast cells secrete a signal molecule called mating factor that attracts them to their mates. Once the mating factor of one yeast binds to the receptor on another yeast, an outgrowth called a "shmoo" forms, which allows the yeast cells to fuse together.

Thinking about the limiting factors of cell size. Focus on volume to surface area ratio.

Introduction to cell theory. Roles of Hooke, Leeuwenhoek and others in its development.

What cellular evidence do we have to construct evolutionary trees and believe that all life on Earth shares a common ancestry?

Learn about the interaction between chemical messages and their target cells in this video about hormone action.

Introduction to cellular respiration, including glycolysis, the Krebs Cycle, and the electron transport chain. Created by Sal Khan.

Introduction to cellular respiration, including glycolysis, the Krebs Cycle, and the electron transport chain. Created by Sal Khan.

Sal gives a conceptual understanding of what center of mass means. Created by Sal Khan.

This video talka about what is easily one of the most fundamental and profound concepts in statistics and maybe in all of mathematics. And that's the central limit theorem.

This art history video discussion examines Paul Cezanne's "Bathers (Les Grandes Baigneuses)," c. 1894-1905, oil on canvas, 127.2 x 196.1 cm (The National Gallery, London).

This art history video discussion examines Paul CŽzanne's "Still Life with Apples," oil on canvas, 1895-98 (MoMA).

This art history video discussion examines Paul Cezanne's "Still Life with Plaster Cupid", oil on canvas, c.1895 (Courtauld Gallery, London).

This art history video discussion examines Paul Cezanne's "The Large Bathers," 1906, oil on canvas, 82-7/8 x 98-3/4 inches / 210.5 x 250.8 cm (Philadelphia Museum of Art).