CELL STRUCTUREBrandon Tran

Period. 2

10/24/14

PLASMA MEMBRANE(CELL MEMBRANE) The cell membrane is selectively

permeable to ions and organic molecules and controls the movement of substances in and out of cells. The basic function of the cell membrane is to protect the cell from its surroundings. It consists of the phospholipid bilayer with embedded proteins. This is an example of a gate which lets things in and things out. It also protects the cell from its surroundings.

NUCLEUSCHROMOSOMESDNA

The cell nucleus acts like the brain of the cell. It helps control eating, movement, and reproduction. If it happens in a cell, chances are the nucleus knows about it. The nucleus is not always in the center of the cell. It will be a big dark spot somewhere in the middle of all of the cytoplasm (cytosol). You probably won't find it near the edge of a cell because that might be a dangerous place for the nucleus to be. If you don't remember, the cytoplasm is the fluid that fills cells. The nucleus is an example of a human brain because it helps control everything.

RIBOSOMES

Cells need to make proteins. Enzymes made of proteins are used to help speed up biological processes. Other proteins support cell functions and are found embedded in membranes. Proteins even make up most of your hair. When a cell needs to make proteins, it looks 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. I chose Bob the Builder as an example because he builds things just like how ribosomes build proteins.

CYTOPLASM

The cytosol in a cell does more than just suspend the organelles. It uses its dissolved enzymes to break down all of those larger molecules. The products can then be used by the organelles of the cell. Glucose may exist in the cytosol but the mitochondria can't use it for fuel. The cytosol has enzymes that break glucose down into pyruvate molecules that are then sent to the mitochondria. I used a wrecking ball as an example because it breaks buildings down just like how cytosol breaks down enzymes.

MITOCHONDRIA

Mitochondria are known as the powerhouses of the cell. They are organelles that act like a digestive system which takes in nutrients, breaks them down, and creates energy rich molecules for the cell. The biochemical processes of the cell are known as cellular respiration. Many of the reactions involved in cellular respiration happen in the mitochondria. Mitochondria are the working organelles that keep the cell full of energy. I chose the human digestive system as an example of mitochondria because it takes nutrients, breaks them down, and creates energy rich molecules for the body.

CHLOROPLASTS Chloroplasts are the food producers of

the cell. The organelles are only found in plant cells and some protists such as algae. Animal cells do not have chloroplasts. Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells. The entire process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast. I chose KFC as an example of chloroplasts because it produces food for us.

CELL WALL

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. Also helps keep its shape. I chose a picture frame as an example of a cell wall because it holds and protects pictures for the picture to stay in good condition.

ROUGH ER Another organelle in the cell is the endoplasmic reticulum (ER). While the function of the nucleus is to act as the cell brain, the ER functions as a manufacturing and packaging system. It works closely with the Golgi apparatus, ribosomes, mRNA, and tRNA. I chose Ups as an example of a rough er because Ups packages things.

SMOOTH ER Smooth ER (SER) acts as a storage

organelle. It is important in the creation and storage of lipids and steroids. Steroids are a type of ringed organic molecule used for many purposes in an organism. They are not always about building the muscle mass of a weight lifter. Cells in your body that release oils also have more SER than most cells. I chose a locker to represent a smooth er because you store things in side the lockers.

GOLGI

The Golgi apparatus gathers simple molecules and combines them to make molecules that are more complex. It then takes those big molecules, packages them in vesicles, and either stores them for later use or sends them out of the cell. It is also the organelle that builds lysosomes (cell digestion machines). Golgi complexes in the plant may also create complex sugars and send them off in secretory vesicles. The vesicles are created in the same way the ER does it. The vesicles are pinched off the membranes and float through the cell. I chose FedEx as a example of golgi because fedex takes things in and packages them and sends it out.

VACUOLES/VESICLES Vacuoles are 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. I chose camel humps as an example of vacuoles/vesicles because their humps store fat which are nutrients.

LARGE CENTRAL VACUOLE

Vacuoles also play an important role in plant structure. Plants use cell walls to provide support and surround cells. The size of that cell may still increase or decrease depending on how much water is present. Plant cells do not shrink because of changes in the amount of cytoplasm. Most of a plant cell's volume depends on the material in vacuoles. I chose a water tower as an example of a large central vacuole because it stores water just like the central vacuole. It gives out water when it is needed.

LYSOSOMES

Lysosomes hold enzymes that were created by the cell. The purpose of the lysosome is to digest things. They might be used to digest food or break down the cell when it dies. A lysosome is basically a specialized vesicle that holds a variety of enzymes. The enzyme proteins are first created in the rough endoplasmic reticulum. Those proteins are packaged in a vesicle and sent to the Golgi apparatus. The Golgi then does its final work to create the digestive enzymes and pinches off a small, very specific vesicle. That vesicle is a lysosome. From there the lysosomes float in the cytoplasm until they are needed. Lysosomes are single-membrane organelles. I chose a stomach as an example of lysosomes because a stomach breaks down the food or digest it.

CENTRIOLES Every animal-like cell has two small organelles called centrioles. They are there to help the cell when it comes time to divide. They are put to work in both the process of mitosis and the process of meiosis. You will usually find them near the nucleus but they cannot be seen when the cell is not dividing. I chose a marriage counselor as an example of centrioles because they help couples divide and without it they have trouble dividing.

MICROTUBULES They are both proteins that help define

cell structure and movement, they are very different molecules. While microfilaments are thin, microtubules are thick, strong spirals of thousands of subunits. Those subunits are made of the protein called tubulin. And yes, they got their name because they look like a tube. An example of microtubules is a human skeleton because it gives movement and it also gives shape, support, and protection.

RESOURCES

www.biology4kids.com/files/cell_nucleus.html

www.biology4kids.com/files/cell_ribos.html

http://www.biology4kids.com/files/cell_cytoplasm.html

www.biology4kids.com/files/cell_mito.html

http://www.biology4kids.com/files/cell_chloroplast.html

http://www.biology4kids.com/files/cell_wall.html

http://www.biology4kids.com/files/cell_er.html

http://www.biology4kids.com/files/cell_er.html

http://www.biology4kids.com/files/cell_golgi.html

http://www.biology4kids.com/files/cell_vacuole.html

http://www.biology4kids.com/files/cell_vacuole.html

http://www.biology4kids.com/files/cell_lysosome.html

http://www.biology4kids.com/files/cell_centriole.html

http://www.biology4kids.com/files/cell_microtubule.html

www.biology.tutorvista.com/animal-and-plant-cells/plasma-membrane.html