Extracellular matrix

An ECM is like a cell wall, they help to structuralize the cell. The main ingredient of the ECM are glycoproteins that are secreted by the cell. Collagen is the most abundant glycoprotein in the ECM and it forms strong fibers outside the cell. The receptor cells called integrins transmitt signal between the ECM and cytoskeleton and integrate changes the occur inside and outside of the cell.

Plasmodesmata

Perforated channels that run through the cell wall are what plasmodesmata are. Cytoplasm passes through the plasmodesmata and connects the chemical environments of adjacent cells. The adjacent cells become continuous because the channel of each plasmodesmata are the same and the cytoplasm acts like a rod would through each individual cell. In some circumstances, certain proteins and RNA molecules can pass freely from cell to cell as water does in small solutes.

Nuclear lamina

The nuclear lamina is a net like array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope.

Flagella

Flagella is responsible for the movement of cells. A special arrangement of microtubules is responsible for the movements of flagella. Some cells that have flagella are: the sperm of animals, algae, and some plants.

Cytoskeleton

Cytoskeleton is responsible for maintaining the shape of the cell and providing anchorage in organelles. It also aids in cell locomotion and organizes the structures and activities of the cell.

The cytoskeleton consists of microtubules, microfilaments, and intermediate filaments.

Vacuole

Vacuoles are responsible for moving material around the cell and storing food and/or waste. In fresh water protists, vacuoles are useed to pump excess water out of the cells. They are also used to store pigments and defensive compounds. They have a selective membrane sac that is filled with digestive enzymes. In animal cells, there is no central vacuole.

Peroxisomes

They break down fatty acids into sugars, detoxify alcohol and other poisons in the cell, and produce peroxide (H2O2 -> H2O + O). Peroxisomes have a lipid bilayers and plasma membranes.

Lysosomes

Lysosomes are used to digest food, clean up and recycle broken organelles. They digest the invaders that have been attacked by white blood cells. Lysosomes are responsible for Apoptosis or the programmed destruction of cells in multi cellular organisms. If lysosomes become diseased they often result in fatality of life. They also have the same structure as vacuoles and are only found in animal cells.

Chloroplast

Chloroplasts generate energy in plant cells, as well as sythesizing sugars. Chloroplasts are semi autonomous: they can move, change shape, and divide plastids. They are membrane bound sacs filled with chlorophyll. Chloroplasts are made of three parts: the stroma, the thylkoids, and the grana.

Mitochondria

The mitochondria makes ATP energy from cellular respiration (sugar+O2 -> ATP). The mitochondria are also responsible for catabolism and aerobic respiration. They reproduce using mitosis. They have two membranes, a smooth outer membrane and a tightly folded inner membrane. The two membranes increase surface area for the membrane bound enzymes.

Smooth Endoplasmic Reticulum

The smooth ER synthesizes lipids and hydrolizes glycogen into glucose. It also detoxifies the cell of drugs/poisons. The main function of the smooth ER is to make membranes.

Rough Endoplasmic Reticulum

The rough endoplasmic reticulum produces proteins for export from cell. It also produces protein secreting cells andthen the rough E.R. package them into transport vesicles. This organelle is recognized by the attachment of ribosomes along the outer wall.

Golgi Apparatus

Finishes the proteins, then sorts them. The proteins are then labeled by the Golgi Apparatus and shipped in vesicles made by the golgi apparatus forming around the proteins and breaking apart from the main body of the golgi apparatus.

Ribosomes

Ribosomes work on proteins. They read instructions on how to build proteins from the DNA. They are made of rRNA and proteins. They occur in two places: free in the cytoplasm or attatched to the rough E.R. The ribosomes can alternate positions between the two. The proteins made in the free ribosomes only function within the cytoplasm. The bound ribosomes usually make proteins that go into membranes, usually for packaging within certain organelles.

Centrioles

Centrioles play a major role in cellular reproduction. The centrioles are responsible for pulling the chromosomes apart during metaphase with spindle fibers. They also organize the microtubules in the cell. This organelle is only found in animals.

Nucleolus

Ribosomes and proteins are built from rRNA in this organelle and then exit through the nuclear pores to the cytoplasm and combine to form functional ribosomes.

Nucleus

This organelle is the control center of the cell. It stores and protects DNA from the outside. It is made of three parts: nuclear membrane, nucleolus, and chromosomes. All this together is called the nuclear envelope. The nuclear membrane is perforated by nuclear pores which connect the inner and outer membrane of the nuclear envelope. These nuclear pores regulate the entry and exit of most proteins and RNA, as well as macromolecules.

Cell Wall

The outer layer of a plant cell that maintains the cell shape and protects the cell from mechanical damage. It is made of cellulose, other polysaccharides, and protein. The cell wall is only found in plants.

Plasma/Cell Membrane

The plasma or cell membrane is a barrier from the outside of the cell and has a phospholipid bilayer with receptor molecules. This membrane controls what enters and exits the cell and can recognize signals from other cells. This is present in both plant and animal cells.