Answer:
Step-by-step explanation:
Cells communicate with each other using chemical signals. These chemical signals are proteins or other molecules produced by a sending cell, which are often secreted from the cell and released into the extracellular space. There, they can float over to neighboring cells⁴. When a signaling molecule binds to its receptor, it alters the shape or activity of the receptor, triggering a change inside the cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors)⁴.
The human body uses molecules held in the fats, proteins, and carbohydrates we eat or drink as sources of energy to make ATP. This happens through a process called hydrolysis. After food is digested, it's synthesized into glucose, which is a form of sugar⁵. ATP is then used by cells to carry out various functions such as active transport³. Active transport is a process by which cells use energy to move molecules across the cell membrane against their concentration gradient³. This process takes place in several steps and involves the use of ATP to power the movement of molecules³.
In summary, cells communicate with each other using chemical signals and use molecules from food to produce ATP, which is then used to carry out various functions such as active transport. This allows cells to move molecules across their membranes and into or out of the cell.
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