Cell theory:
-All living things are made up of cells.
-Cells are the basic units of structure and function in living things.
-New cells are produced from existing cells.

Cells are studied through microscopes.

Eukaryotes cells.- Are cells that enclose their DNA in uncle. They're mostly more complex cells.
Prokaryotes cells.- Are cells that do not enclose DNA in nuclei.

Cell parts:
Cytoplasm.- With its fluids and chemical it carries out the life processes.
Vesicle.- It stores substances.
Vacuoles.- Vacuoles also store substances.
Golgi apparatus.- It modifies, sorts and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell.
Mitochondria.- It convert the chemical energy stored in food into compounds that are more convenient for the cell to use.
Lysosome.- Breaks down lipids, carbohydrates and proteins into small molecules that can be used by the rest of the cell. They are also involved in breaking down organelles that have outlived their usefulness.
Centrioles.- They help organize cell division.
Cytoskeleton.- Helps the cell maintain its shape and is also involved in movement.
Smooth ER.- It acts as pathway throughout the cytoplasm. It also produces lipids for the cell.
Rough ER.- It produces proteins.
Ribosome.- It also produces proteins
Nucleus.- It controls all cell activity. It contains the DNA.
Cell Membrane.- Gives shape to the cell. It has a lipid bilayer.
Chloroplasts.- They capture the energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis. (only plant cells).
Cell Wall.- Strong supporting layer around the membrane that protects the cell. (only plant cells).
The cell membrane is called a Fluid Mosaic because proteins float among the lipids and many kind of molecules make up the cell membrane, so it looks like many structures over a monotonous background, like a mosaic.

Cell transport
Diffusion.- The process by which molecules of a substance move from areas of higher concentration to areas of lower concentration. Equilibrium is reached when the concentration of the solute is the same throughout a solution.
Osmosis.- The diffusion of water through a selectively permeable membrane. Types of osmosis pressure:
- Isotonic.- Cells neither gain or lose water.
- Hypertonic.- The pressure is higher than in another part.
- Hypotonic.- The pressure is lower than in another part.
Facilitated diffusion.- Molecules that cannot pass the lipid bilayer of the cell membrane move across through protein channels. This protein membrane helps or facilitates the movement of glucose in and out of the membrane. It doesn't require cell's energy because the molecules are moving from an area of high concentration to an area of low concentration.
Active transport.- Movement of material from low concentration zones to high concentration zones. It requires energy. Kinds:
-Endocytosis.- Materials are unfolded or pocketed to move from low concentration to high concentration zones.
-Phagocytosis.- Is when materials are moved into the cell through endocytosis.รง
-Exocytosis.- Is when materials leave the cell through endocytosis.
Homeostasis in cells.- To maintain homeostasis, unicellular organism grow, respond to the environment, transform energy and reproduce. The cells of multicellular organisms become specialized for particular tasks and communicate with one another to maintain homeostasis.