Chapter 7.2 Assessmemt

3.A. What is the difference between the rough and smooth ER?

Rough ER's have ribosomes on the surface and produce large amounts of proteins for export. Smooth ER's contain a collection of specialized enzymes and does not have ribosomes on its surface.

5.B. How do the properties of lipids help explain the structure of the cell membrane?

Since the heads of lipids are hydrophilic and the tails are hydrophobic, water being mixed with these lipids causes the formation of a cell membrane.

4.B. You examine an unknown cell under a microscope and discover that the cell contains chloroplasts. From what type of organism does the cell likely come?

Most likely plants.

3.B. Describe the steps involved in the synthesis, packaging, and export of a protein from a cell.

1.) Proteins are assembled on ribosomes. 2.) Proteins targeted for export to the cell membrane, or to specialized locations within the cell, complete their assembly on ribosomes bound to the rough endoplasmic reticulum. 3.) Newly assembled proteins are carried from the rough endoplasmic reticulum to the Golgi apparatus in vesicles. 4.) The Golgi apparatus further modifies proteins before sorting and packaging them in membrane-bound vesicles. 5.) Vesicles from the Golgi apparatus are shipped to their final destination in, our out of, the cell.

5.C. Why do you think it's important that cell membranes are selectively permeable?

It keeps in the necessary, vital materials and keeps out the large, unneeded materials. These unneeded materials could potentially harm the cell in some way.

4.A. What is the function of mitochondria?

It processes chemical energy into more digestible compounds for general cellular use.

5.A. Why is the cell membrane sometimes referred to as a fluid mosaic? What part of the cell membrane acts like a fluid? And what makes it like a mosaic?

It's referred to as a fluid mosaic because the cell membrane contains many different molecules that move around, as of objects in a fluid.

1.A. What are the two major parts of the cell?

The cell membrane and the nucleus.

2.B. How do contractile vacuoles help maintain water balance?

The contractile vacuoles pump excess water out of the cell (hence the name "contractile").

1.B. How is the role of the nucleus on a cell similar to the role of the captain on a sports team?

They both lead a group of components and control what occurs between those components.

2.A. What is the function of lysosomes?

To breaks down lipids, carbohydrates, and proteins into small molecules that can used by the rest of the cell.