Cell Membrane and Transport

Which of the following molecules is most important in the building of cellular membranes?

• Starch
• Nucleic Acids
• Carbohydrates
• Phospholipids

What is the function of a cell’s selectively permeable plasma membrane?

• It helps the cell to manufacture proteins.
• It regulates the amount of ATP the cell produces.
• It regulates what materials enter and leave the cell.
• It packages and stores most of the material in a cell. 

Cells use passive and active transport to move materials across cell membranes in   order to maintain a constant internal environment. What is the process of maintaining a constant internal environment called?

• Diffusion
• Evolution
• Homeostasis
• Respiration

Which of the following is an example of passive transport across the cell membrane? 

• Endocytosis
• Exocytosis
• Facilitated Diffusion
• Phagocytosis

Very large molecules are moved out of the cell by which of the following processes?

• Pinocytosis
• Phagocytosis
• Endocytosis
• Exocytosis

What is the correct description of the relationship between osmosis and diffusion?

• Diffusion is a type of osmosis that occurs across a cell membrane using just solid particles. 
• Osmosis is a type of diffusion that pertains to just water molecules and occurs across a cell membrane. 
• Osmosis is a type of diffusion that requires extra energy on the part of the cell, whereas diffusion happens freely.
• Osmosis is not directly related to diffusion. Osmosis involves the movement of liquids. Diffusion involves movement of gases.

In the picture above, the cell is taking in substances through membrane proteins, without any energy outlay of its own. The substances naturally follow their concentration gradient. However, they must go through the protein channels, because they are too large to squeeze through the cell membrane. This process is called

• Osmosis
• Endocytosis
• Active Transport
• Facilitated Diffusion

Water is leaving the cell.  How would we describe the solution outside the cell?  It is said to be

• Hypotonic
• Hypertonic
• Isotonic
• Homeostasis

Water has been moving into the cells until they burst. Into what type of solution have these cells been placed? 

• Hypotonic
• Hypertonic
• Isotonic
• Homeostasis

In the picture, what types of transport are being shown?

• Endocytosis and exocytosis
• Endocytosis and facilitated diffusion
• Exocytosis and osmosis
• Pinocytosis and facilitated diffusion