Organelles
Since cells are responsible for so many functions in your body, they have to use a variety of resources within them to make sure every job gets done. You can think of your cells as factories. Within each factory, there are many different rooms that are responsible for different types of tasks. For example, there is the boss’s office, which contains all of the guidelines for running the factory, janitors’ closet, which has equipment for cleaning the factory, a section for the generator, which makes energy for the factory, and workbenches on which various products are manufactured. In your cells, these rooms and compartments are called organelles. It is important that all of the different areas are isolated from each other so that the factory runs efficiently. For example, you wouldn’t want the workbenches, janitorial supplies, and the factory manual to all be sitting in random places in the factory. This wouldn’t be very efficient. Cells also must make sure that they only have as many rooms and equipment as they need. To be as efficient as possible, cells have different proportions of organelles depending on what they need to accomplish for the organism. All the organelles in your cells have to work together to get all the jobs done, just like in the different rooms of a factory. Overall organelles are a way for cells to organize all the jobs that need to be done into different compartments. This division creates a more efficient cell with fewer errors.
Plasma membrane
For protection, a factory has a number of mechanisms such as the exterior building like walls and a roof, loading docks to make sure only trucks that are carrying things the factory needs are allowed to unload, and employees that check to make sure the right things are going in and out of the factory. Similar mechanisms are used in a cell. The cell has a cell membrane that makes sure only certain things go in and out of the cell. This is similar to doors and windows in a factory: some doors are opened, some windows are opened, but those doors and windows can also be locked so nothing can be allowed to go through. These windows and doors in a cell are simply proteins within the cell membrane. These proteins receive information from other cells in the body, which affects the way the cell operates inside. The interactions between the outside world and the cell interior are mediated by the plasma membrane.
Ribosome
The workbench in a factory where products are made is like a ribosome in a cell. As you would imagine, factories need to make a lot of products so one workbench would not be enough. Cells also have workbenches called ribosomes. Ribosomes make the proteins in your cells. The more protein the cell needs, the more ribosomes it has. If you were to look in the microscope at hair-follicle cells, or other cells that make lots of protein, you would find lots and lots ribosomes; in a fat-storage cell, however, you would not find as many ribosomes. Proteins are the most important molecules in our bodies. They do virtually all of the work that a cell needs. There are many types of proteins that serve many different functions, such as turning cellular equipment on and off, letting things into and out of cells, and providing structure for the cell. Since proteins serve such a major role in our cells and bodies, ribosomes are also very important since they are where proteins are made.
Nucleus
Then nucleus of a cell provides a headquarters that oversees all functions of the cell. The nucleus is similar to an office in a factory. The factory office contains all the instructions manuals for the machines and employees of the factory. The nucleus also contains instruction manuals called DNA. DNA is the genetic instruction manual that contains directions to make proteins that work to make your body operate. Just as an office in a factory can give a manual to an employee to do a specific job, the nucleus can send instructions to the ribosomes to make specific proteins. Not all DNA is used; some of the instructions are saved for special functions or events in your body. Since DNA is such an important part of the cell, the nucleus also has a strong membrane to protect that DNA. If the DNA gets damaged the cell won’t operate properly. Damaged DNA is responsible for many diseases such as cancer.
Mitochondria
The cell, like any factory, needs energy in order to carry out its functions. Without energy cells could not ensure that they make what they need and move what they made to where it is needed, for example. Cells make energy by chemically burning fuel (think coal plant which makes electricity). Each cell has its own energy production centers where they make energy to charge battery-like molecules that provide energy where it is needed. These power-plant-like compartments that burn fuel to charge the batteries, are called mitochondria. Instead of coal, cells use sugar and fat from our diet to get energy. Cells in our body that need a lot of energy are muscle cells that help us move. Muscle cells have many more mitochondria than cells that do not have to spend so much energy. The process of making energy from food is called cellular respiration. Cellular respiration happens in the mitochondria and requires oxygen and releases carbon dioxide. This is why we breathe in oxygen, and exhale carbon dioxide.
Plant Cells
Plants look very different from animals. This difference is due to the differences in cells between plants and animals. While the basis of cell operations remains the same, plant cells contain unique organelles that give them distinct properties from animal cells.
Cell Wall
In order for plants to be upright their entire lives, they must have something strong and supportive to allow that. For this reason, outside the plasma membrane, plant cells have what a strong cage that keeps the cell from swelling too much and exploding when they take in a lot of water. This cage is called a cell wall.
Chloroplasts
Because plants cannot move to catch or eat their food, they have a mechanism for making their own food. Just as a factory can use solar panel to provide electricity, plants can also use the sun to make their own energy. These solar panels are like chloroplasts. They are what give plants their green color. Plants make their food in a process called photosynthesis, which uses the chloroplasts. Chloroplasts are where carbon dioxide and water are made into sugar that is later broken down and turned into energy in mitochondria. Because photosynthesis requires take in of carbon dioxide and release of oxygen, and humans breathe in oxygen and release carbon dioxide, plants are essential for human life and our environment.
Vacuole
Plants have another structure that is unique from animal cells. This special organelle is responsible for storing water. Because plants cannot move from a dry area to a pond to get water, they have to have a place to store water when there is excess, and use that saved water when there is a shortage. These water-reserves are called vacuoles. When a plant is watered the vacuole fills will water and causes the membrane to push against the cell wall, and this pressure helps the plant to stand up straight. This is why plants begin to wilt if they are not watered enough: water in vacuoles is used up and cells are no longer large enough to keep the cell walls rigid.
Plasma membrane
For protection, a factory has a number of mechanisms such as the exterior building like walls and a roof, loading docks to make sure only trucks that are carrying things the factory needs are allowed to unload, and employees that check to make sure the right things are going in and out of the factory. Similar mechanisms are used in a cell. The cell has a cell membrane that makes sure only certain things go in and out of the cell. This is similar to doors and windows in a factory: some doors are opened, some windows are opened, but those doors and windows can also be locked so nothing can be allowed to go through. These windows and doors in a cell are simply proteins within the cell membrane. These proteins receive information from other cells in the body, which affects the way the cell operates inside. The interactions between the outside world and the cell interior are mediated by the plasma membrane.
Ribosome
The workbench in a factory where products are made is like a ribosome in a cell. As you would imagine, factories need to make a lot of products so one workbench would not be enough. Cells also have workbenches called ribosomes. Ribosomes make the proteins in your cells. The more protein the cell needs, the more ribosomes it has. If you were to look in the microscope at hair-follicle cells, or other cells that make lots of protein, you would find lots and lots ribosomes; in a fat-storage cell, however, you would not find as many ribosomes. Proteins are the most important molecules in our bodies. They do virtually all of the work that a cell needs. There are many types of proteins that serve many different functions, such as turning cellular equipment on and off, letting things into and out of cells, and providing structure for the cell. Since proteins serve such a major role in our cells and bodies, ribosomes are also very important since they are where proteins are made.
Nucleus
Then nucleus of a cell provides a headquarters that oversees all functions of the cell. The nucleus is similar to an office in a factory. The factory office contains all the instructions manuals for the machines and employees of the factory. The nucleus also contains instruction manuals called DNA. DNA is the genetic instruction manual that contains directions to make proteins that work to make your body operate. Just as an office in a factory can give a manual to an employee to do a specific job, the nucleus can send instructions to the ribosomes to make specific proteins. Not all DNA is used; some of the instructions are saved for special functions or events in your body. Since DNA is such an important part of the cell, the nucleus also has a strong membrane to protect that DNA. If the DNA gets damaged the cell won’t operate properly. Damaged DNA is responsible for many diseases such as cancer.
Mitochondria
The cell, like any factory, needs energy in order to carry out its functions. Without energy cells could not ensure that they make what they need and move what they made to where it is needed, for example. Cells make energy by chemically burning fuel (think coal plant which makes electricity). Each cell has its own energy production centers where they make energy to charge battery-like molecules that provide energy where it is needed. These power-plant-like compartments that burn fuel to charge the batteries, are called mitochondria. Instead of coal, cells use sugar and fat from our diet to get energy. Cells in our body that need a lot of energy are muscle cells that help us move. Muscle cells have many more mitochondria than cells that do not have to spend so much energy. The process of making energy from food is called cellular respiration. Cellular respiration happens in the mitochondria and requires oxygen and releases carbon dioxide. This is why we breathe in oxygen, and exhale carbon dioxide.
Plant Cells
Plants look very different from animals. This difference is due to the differences in cells between plants and animals. While the basis of cell operations remains the same, plant cells contain unique organelles that give them distinct properties from animal cells.
Cell Wall
In order for plants to be upright their entire lives, they must have something strong and supportive to allow that. For this reason, outside the plasma membrane, plant cells have what a strong cage that keeps the cell from swelling too much and exploding when they take in a lot of water. This cage is called a cell wall.
Chloroplasts
Because plants cannot move to catch or eat their food, they have a mechanism for making their own food. Just as a factory can use solar panel to provide electricity, plants can also use the sun to make their own energy. These solar panels are like chloroplasts. They are what give plants their green color. Plants make their food in a process called photosynthesis, which uses the chloroplasts. Chloroplasts are where carbon dioxide and water are made into sugar that is later broken down and turned into energy in mitochondria. Because photosynthesis requires take in of carbon dioxide and release of oxygen, and humans breathe in oxygen and release carbon dioxide, plants are essential for human life and our environment.
Vacuole
Plants have another structure that is unique from animal cells. This special organelle is responsible for storing water. Because plants cannot move from a dry area to a pond to get water, they have to have a place to store water when there is excess, and use that saved water when there is a shortage. These water-reserves are called vacuoles. When a plant is watered the vacuole fills will water and causes the membrane to push against the cell wall, and this pressure helps the plant to stand up straight. This is why plants begin to wilt if they are not watered enough: water in vacuoles is used up and cells are no longer large enough to keep the cell walls rigid.