How cells work[take a quiz on this topic] |
| Chapter One: An Introduction to Cells |
The other chapters in the Guide are devoted to explaining all of the details about how a cell works, but here is a general explanation to get you started.
Cells have tiny structures inside of them called organelles. Organelles are very similar to human organs in that they help perform specific functions. However, cells don't have organelles called "the liver" or "the heart." Some of the names of cell organelles include the mitochondria, lysosomes, and the endoplasmic reticulum. Don't get scared by the strange names; Chapter Three focuses on cell organelles so that you can understand them completely.
The cell organelles float around in a fluidic substance called the cytoplasm. The cytoplasm is similar to very watery jelly. As the cytoplasm moves around within the cell, organelles can come into contact with one another, allowing certain processes to occur. This movement of the cytoplasm is called cyclosis.
Just like humans, cells need to perform certain processes similar to our processes for eating, breathing, and reproduction. These processes have some very interesting names: phagocytosis, glycolysis, mitosis. Chapters Four and Five explain all of the processes which occur in cells.
There's just one more thing to talk about, and that's DNA. DNA stands for deoxyribonucleic acid. It's a huge molecule found in the nucleus (the "brain-like" organelle) of every cell. In multicellular organisms like humans, DNA is involved in determining your height, your eye color, your personality, and many other things. Unicellular organisms don't really have personality, or an eye color, or even height, so you might wonder what does DNA do for them. Through a series of processes which we will discuss in Chapter Six, DNA produces molecules known as proteins. Proteins, in turn, are very important in determining whether or not other cell processes, such as reproduction, will occur.