Calculate the surface-to-volume ratio for the spherical bacterium Neisseria gonorrhoeae, responsible for the disease gonorrhea. Compare it with the surface-to-volume ratio for a globular amoeba, a large eukaryotic cell.

计算导致gonorrhea病的球形细菌Neisseria gonorrhoeae的表/体比。并与球形的大的真核细胞阿米巴比较。

属类：化学及生命科学-化学-化学习题

Certain cells whose function is to absorb nutrients, such as the cells lining the small intestine or the root hair cells of a plant, are optimally adapted to their role because their exposed surface area is increased by microvilli.

某些细胞的功能是吸收营养,如小肠中的细胞内衬、植物的根毛细胞最佳地适应了其作用,因为它们通过微绒毛增加了其暴露的表面积。

属类：化学及生命科学-化学-化学习题

Consider a spherical epithelial cell (diameter 20 μm)in the lining of the small intestine.

以小肠绒毛球形上皮细胞(直径20μm)为例。

属类：化学及生命科学-化学-化学习题

Given that only a part of the cell surface faces the interior of the intestine, assume that a "patch" corresponding to 25% of the cell area is covered with microvilli.

由于只有一部分细胞表面面向小肠的内部,假定一小块大约表面的25%是由绒毛覆盖的,

属类：化学及生命科学-化学-化学习题

Furthermore, assume that the microvilli are cylinders 0.1μm in diameter, 1.0 μm long, and spaced in a regular grid 0.2 μm on center.

再进一步假定绒毛是圆柱形的,直径为0.1μm,长1.0μm,绒毛间的中心距离为规则的0.2μm

属类：化学及生命科学-化学-化学习题

Calculate the number of microvilli on the patch.

计算一小块的绒毛数。

属类：化学及生命科学-化学-化学习题

Calculate the surface area of the patch, assuming it has no microvilli.

假设没有微绒毛计算一小块的表面积。

属类：化学及生命科学-化学-化学习题

Calculate the surface area of the patch, assuming it does have microvilli.

假设有微绒毛计算一小块的表面积。

属类：化学及生命科学-化学-化学习题

What percentage improvement in absorptive capacity (reflected by the surface-to-volume ratio)does the presence of microvilli provide?

微绒毛的存在使吸收能力(用表体比表示)提高的百分比是多少?

属类：化学及生命科学-化学-化学习题

What other organelles and organ systems utilize this strategy to improve absorptive capacity?

还有哪些其它的细胞器和器官系统采取此种策略提高吸收能力?

属类：化学及生命科学-化学-化学习题