1. After carefully reviewing Figure 6.8, briefly describe the structure and function of the nucleus, the mitochondrion, the chloroplast, and the endoplasmic reticulum.
Nucleus- nonmembranous structure involved in production of ribosomes; a nucleus has one or more nuclueoli
Mitochondrion- organelle where cellular respiration occurs and most ATP is generated Chloroplast- photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules
Endoplasmic reticulum- network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes
2. Imagine an elongated cell (such as a nerve cell) that measures 125 1 1 arbitrary units. Predict how its surface- to- volume ratio would compare with those in Figure 6.7. Then calculate the ratio and check your prediction.
-This cell would have the same volume as the cells in columns 2 and 3 but proportionally more surface -area than that in column 2 and less than that in column 3. -125 x 125 x 125 x 125 x 1 x 1 x 502. The surface-to-volume ratio equals 502 divided by a volume of 125, or 4.0.
3. Explain how the compartmental organization of a eukaryotic cell contributes to its biochemical functioning.
Cells are divided into several compartments, each with a characteristic structure, biochemical composition, and function (see illustration). These compartments are called organelles. They are delimited by membranes composed of phospholipid bilayers and a number of proteins specialized for each type of organelle.