Can anyone help me with my bio homework?

Question

Explain why there are both the upper and the lower limits to cell size and explain why compartmentalization is important to eukaryotic cells.

describe the structure and functions of the microtubules, microfilaments, and intermidiate filaments. explain how the ultrastructure of cilia and flagella relate to thier functions.

Please if anyone has any idea can you help me? thanks:)

Answer 1

Cell Size is governed by several factors: The size of the cell is controlled by metabolic requirements. DNA must be available to produce the enzymes and proteins needed for proper functioning. A too small cell will not have enough DNA to support life and a cell too large will need an enormous amount of DNA to carry on its functions. A second restriction involves surface area to volume ratio. As the cell increases in size, the volume increases geometrically while the surface area increases arithmetically. Eukaryotic cells cope with these problems in that they contain membrane bound organelles. These organelles break up the volume of the cell performing distinct functions which cuts down on the raw materials needed. Each part of the cell does not need the same material to function.

Cytoskeleton contains microtubules and microfilaments. Microtubules: straight hollow rods measuring about 25 nm. thick . They are constructed from a and b tubulin. They shape, support and help move organelles around the cell. They form centrioles, which are not found in plants. They have a "9 + 2 " pattern. Microfilaments: are constructed of 2 interwoven pieces of actin about 7nm. in diameter. They function in muscle contraction, cytoplasmic streaming, ameboid movement, and changes in cell shape.