Section 2: Movement of Substances 6. Molecules naturally move from areas of __ concentration to __ concentration in a process called __ 7. Water moves across membranes through a specific type of diffusion known as __ 8. A process that allows large or charged molecules to pass through the membrane with the help of proteins , but without energy use is called __ 9. When a cell expends energy to move substances against their concentration gradient, it is performing __ 10. If a cell is placed in a solution that causes it to swell, the solution is __ , whereas if the cell shrinks, the solution is __

## Step 1<br />The first question is about the natural movement of molecules from areas of high concentration to areas of low concentration. This process is known as diffusion.<br /><br />## Step 2<br />The second question refers to the movement of water across membranes. This process is known as osmosis.<br /><br />## Step 3<br />The third question is about a process that allows large or charged molecules to pass through the membrane with the help of proteins, but without energy use. This process is known as facilitated diffusion.<br /><br />## Step 4<br />The fourth question is about the process where a cell expends energy to move substances against their concentration gradient. This process is known as active transport.<br /><br />## Step 5<br />The fifth question is about the type of solution that causes a cell to swell or shrink. If a cell is placed in a solution that causes it to swell, the solution is hypotonic. If the cell shrinks, the solution is hypertonic.