As you can see in this video, it is really hard to see the organelles inside a cell. It requires a really really strong type of microscope that uses more than just light. We can't see inside the cell very well with the equipment we have, so lets take a look at a video of what the organelles may look like if we could magnify them a ton!
- Mitochondria are rod shaped and generate power for the cell to function. They convert oxygen and other nutrients into ATP.
- The organelle consists of an outer membrane and another interior membrane. The compartments formed work together in the chemical process of making ATP.
- It is important to note that mitochondria have their own DNA reproduce independently of the cell. They also contain ribosomes, another important organelle, inside them.
- The nucleus functions in storing the DNA of the cell and coordinating cell activity such as metabolism, growth, protein synthesis, and reproduction. The nucleus is only found in eukaryotes and there is almost always only one in each cell.
- It is surrounded by the nuclear envelope. This envelope contains pores all around it to allow molecules to pass between the nucleus and cytoplasm.
- The nucleolus is inside the nucleus and it produces ribosomes.
- The endolplasmic reticulum (or ER) is a network of flattened sac and tubes formed by one membrane that continuously folds upon itself.
- It functions in manufacturing and processing many chemical compounds needed by the cell.
- The Rough ER is the ER that has ribosomes covering it. This ER produces proteins to be secreted by the cell.
- The Smooth ET produces fats (lipids), carbohydrate building blocks, and detoxifies some poisons. This means it is more abundant in cells that are associated with these activities such as the brain or liver cells. In muscle cells it releases calcium to help contract the muscles.
- All living cells contain ribosomes.
- These small organelles are composed of mostly RNA and protein, and unlike most organelles are not membrane bound.
- They function as the main protein manufacturers for the cell.
- In eukaryotes they are made inside the nucleolus.
- There are many types of vesicles.
- These organelles are membrane-bound and formed by either endocytosis at the cell membrane or by the ER or golgi complex.
- Notice the double ring of that forms the membrane.
- Their job is to carry substances around the cell to different organelles.
- The Golgi apparatus (or GA) consists of 5 to 8 membrane sacs that look similar to the ER. The sacs are not however connected as one.
- It functions in modifying proteins and fats (lipids) that were built in the ER. It then prepares the chemical products to be shipped around or outside the cell.
- It ships compounds by budding off vesicles.
- Lysosomes digest cellular materials that are no longer useful. They can break down fats, carbohydrates, proteins, and other molecules to be recycled by the cell. T
- o do this lysosomes use many different enzymes made in the ER and modified by the GR.
- Lysosomes are usually budded from the Golgi with the enzymes inside.
- All living cells have a plasma membrane. It serves as a barrier to the outside environment but is permeable to specific molecules and nutrients. It also allows waste to exit the cell.
- Some molecules that are small such as oxygen, carbon dioxide, and water can pass freely through the membrane. (Red chains in picture)
- Larger molecules such as amino acids and sugars are regulated across by transport proteins. (Large green shape in picture)
- This membrane consists of a double layer of lipids. These lipids are hydrophilic (water-loving) on their heads (tan in picture) and hydrophobic (water-fearing) at their tails (reddish brown in picture). The tails face inward and the heads face outward.
Now that we've learned the functions of the organelles lets see them in action!
Take some time to learn more about the organelles with one of these interactive models.