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A membrane-bounded organelle, found in the cytoplasm of eukaryotic cells, which contains digestive enzymes. It acts as the "garbage disposal" of the cell by breaking down cell components that are no longer needed as well as molecules or even bacteria that are ingested by the cell. The interior of a lysosome is strongly acidic, and its enzymes are active at an acid pH. Lysosomes are found in all eukaryotic cells, but are most numerous in disease-fighting cells, such as leukocytes (white blood cells).

The Golgi apparatus (GA), also called Golgi body or Golgi complex and found universally in both plant and animal cells, is typically comprised of a series of five to eight cup-shaped, membrane-covered sacs called cisternae that look something like a stack of deflated balloons. In some unicellular flagellates, however, as many as 60 cisternae may combine to make up the Golgi apparatus. Similarly, the number of Golgi bodies in a cell varies according to its function. Animal cells generally contain between ten and twenty Golgi stacks per cell, which are linked into a single complex by tubular connections between cisternae. This complex is usually located close to the cell nucleus.

has its purpose in the cell. It acts as a storage organelle. It is important in the creation and storage of steroids. It also stores ions in solution that the cell may need at a later time. Steroids are a type of ringed organic molecule used for many purposes in an organism. They are not always about building muscle mass like a weight lifter. The ion storage is important because sometimes a cell needs ions fast. It might not want to search the environment for ions, so it is easier to have them stored in a pack for easy use.

was mentioned in the section on ribosomes. They are very important in the synthesis and packaging of proteins. Some of those proteins might be used in the cell and some are sent out. The ribosomes are attached to the membrane of the ER. As the ribosome builds the amino acid chain, the chain is pushed into the ER. When the protein is complete, the rough ER pinches off a vesicle. That vesicle, a small membrane bubble, can move to the cell membrane or the Golgi apparatus.

Cells need to make proteins. Those proteins might be used as enzymes or as support for other cell functions. When you need to make proteins, you look for ribosomes. Ribosomes are the protein builders or the protein synthesizers of the cell. They are like construction guys who connect one amino acid at a time and build long chains. A ribosome is not just one piece. There are two pieces or subunits. Scientists named them 60-S (large) and 40-S (small). When the cell needs to make protein, mRNA is created in the nucleus. The mRNA is then sent into the cell and the ribosomes. When it is time to make the protein, the two subunits come together and combine with the mRNA. The subunits lock onto the mRNA and start the protein synthesis.

is the fluid that fills a cell. Scientists used to call the fluid protoplasm. Early on, they didn't know about the many different types of fluids in the cell. There is special fluid in the mitochondria, endoplasmic reticulum, Golgi apparatus, and nucleus. The only two 'plasms' left are cytoplasm (the fluid in the cell also called cytosol) and nucleoplasm (the fluid in the nucleus). Each of those fluids has a very different composition. The cell organelles are suspended in the cytosol. You will learn that the microfilaments and microtubules set up a "skeleton" of the cell and the cytosol fills the spaces. The cytoplasm has many different molecules dissolved in solution. You'll find enzymes, fatty acids, sugars, and amino acids that are used to keep the cell working. Waste products are also dissolved before they are taken in by vacuoles or sent out of the cell.

Mitochondria are known as the powerhouses of the cell. They are organelles that act like a digestive system that takes in nutrients, breaks them down, and creates energy for the cell. The process of creating cell energy is known as cellular respiration. Most of the chemical reactions involved in cellular respiration happen in the mitochondria. A mitochondrion is shaped perfectly to maximize its efforts. Mitochondria are very small organelles. You might find cells with several thousand mitochondria. The number depends on what the cell needs to do. If the purpose of the cell is to transmit nerve impulses, there will be fewer mitochondria than in a muscle cell that needs loads of energy. If the cell feels it is not getting enough energy to survive, more mitochondria can be created. Sometimes they can even grow, move, and combine with other mitochondria, depending on the cell's needs.Cell

While cell membranes might be around every cell, cell walls made of cellulose are only found around plant cells. Cell walls are made of specialized sugars called cellulose. Cellulose provides a protected framework for a plant cell to survive. It's like taking a water balloon and putting it in a cardboard box. The balloon is protected from the outside world. Cellulose is called a structural carbohydrate (complex sugar) because it is used in protection and support. Cell walls also help a plant keep its shape. While they do protect the cells, cell walls and cellulose also allow plants to grow to great heights. While you have a skeleton to hold you up, a 100-foot tall redwood tree does not. It uses the strong cell walls to maintain its shape. For smaller plants, cell walls are slightly elastic. Wind can push them over and then they bounce back. Big redwoods need strength in high winds and sway very little (except at the top).

: are the food producers of the cell. They are only found in plant cells and some protists. Animal cells do not have chloroplasts. Every green plant you see is working to convert the energy of the sun into sugars. Plants are the basis of all life on Earth. They create sugars, and the byproduct of that process is the oxygen that we breathe. That process happens in the chloroplast. Mitochondria work in the opposite direction and break down the sugars and nutrients that the cell receives.Va

: Is storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination. Eventually, those waste products would be sent out of the cell. The structure of vacuoles is fairly simple. There is a membrane that surrounds a mass of fluid. In that fluid are nutrients or waste products. Plants may also use vacuoles to store water. Those tiny water bags help to support the plant. They are closely related to objects called vesicles that are found throughout the cell.