36 Chapter 2. What’s inside cells[[Student version, December 8, 2002]]
Figure 2.6:(Electron micrograph.) Budding yeast cell, a simple eukaryote (14 000×magnification). The nucleus
(n) is in the process of dividing. Pores in the nuclear surface are clearly visible. Also shown is a vacuole (v) and several
mitochondria (m, lower left). The sample was prepared by flash-freezing, cleaving the frozen block, then heating
gently in a vacuum chamber to remove outer layers of ice. A replica in carbon-platinum mixture was then made
from the surface thus revealed, and finally examined in the electron microscope. [From (Dodge, 1968)] [Copyrighted
figure; permission pending.]
(see Chapter 11). Mitochondria divide independently of the surrounding cell; when the cell divides,
each daughter cell gets some of the parent’s intact mitochondria.
Eukaryotic cells also contain several other classes of organelles (Figures 2.6–2.8):
- The “endoplasmic reticulum” is a labyrinthine structure attached to the nucleus. It
serves as the main factory for the synthesis of the cell’s membrane structures, as well
as most of the products destined for export outside the cell. - Products from the endoplasmic reticulum in turn get sent to the “Golgi apparatus”
for further processing, modification, sorting, and packaging. - Green plants contain “chloroplasts.” Like mitochondria, chloroplasts manufacture the