Peluche

Only available on StudyMode
  • Download(s) : 54
  • Published : May 16, 2013
Open Document
Text Preview
 Eukaryotic cells have internal membranes that compartmentalize their functions 

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. 
tracking img