Question

cell boundaries
teks focus: 4b cellular processes including permeability and transportation of molecules
this section describes the main functions of the cell membrane. it also explains what happens during diffusion and explains what osmosis is.
cell membrane

1. what are the functions of the cell membrane?
2. the core of nearly all cell membranes is a double - layered sheet called a(an)
3. what is the difference in the function of the proteins and the carbohydrates attached to a cell membrane?

cell walls

1. in what organisms are cell walls found?
2. is the following sentence true or false? the cell wall lies inside the cell membrane.
3. what is the main function of the cell wall?
4. what are plant cell walls mostly made of?

diffusion through cell boundaries

1. the cytoplasm of a cell is a solution of many different substances in
2. what is the concentration of a solution?
3. what is diffusion?

Explanation:

1. The cell - membrane functions include regulating what enters and leaves the cell, providing protection and support, and facilitating communication.
2. The core of nearly all cell membranes is a lipid bilayer.
3. Proteins in the cell membrane can function in transport, as receptors, or as enzymes. Carbohydrates are mainly for cell - cell recognition.
4. Cell walls are found in plants, fungi, bacteria, and some protists.
5. False. The cell wall lies outside the cell membrane in cells that have both.
6. The main function of the cell wall is to provide structural support and protection.
7. Plant cell walls are mostly made of cellulose.
8. The cytoplasm of a cell is a solution of many different substances in water.
9. The concentration of a solution is the mass of solute in a given volume of solution, or mass/volume.
10. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration.

Answer:

1. Regulates transport, provides protection/support, and facilitates communication.
2. Lipid bilayer
3. Proteins: transport, receptors, enzymes; Carbohydrates: cell - cell recognition.
4. Plants, fungi, bacteria, some protists
5. False
6. Provide structural support and protection
7. Cellulose
8. Water
9. Mass of solute in a given volume of solution (mass/volume)
10. Movement of molecules from high to low concentration.