Cell Structure and Organelles

Prokaryotic - no nucleus - single celled - much smaller and simpler. e.g. bacteria

Eukaryotic - has a nucleus- multicellular organisms - plant and animal cells

Organelles

Round in shape, surrounded by a membrane, with no clear internal structure,

ORGANELLE	DIAGRAM	DESCRIPTION	FUNCTION
Plasma Membrane		Found on the surface of animal cells, and just inside plant cell walls and prokaryotic cells. It is made of proteins and lipids.	Regulates the movement of substances entering and exiting the cell. It also has receptor molecules so it can respond to chemicals such as hormones.
Cell Wall		Rigid structure that surrounds plant cells and mostly consists of cellulose.	Mostly for support.
Nucleus		A large organelle surrounded by a nuclear envelope, which  contains some pores. The nucleus contains chromatin (DNA and Proteins) and also contains a structure called a nucleolus	Controls what the cell does. The pores allow substances (RNA) to move between the nucleus and the cytoplasm. The nucleolus makes ribosomes.
Lysosome		Contains digestive enzymes, which are kept separate from the cytoplasm ---------------> They can be used to digest invading cells, or to break down worn-out components of the cell.
Ribosome		Very small, and floats free in the cytoplasm, or can be found attached to the RER. It's made up of proteins and RNA. It has no membrane.	The site of protein production.
Rough Endoplasmic Reticulum (RER)		A system of membranes enclosing a fluid-filled space. The surface is covered with ribosomes.	Folds  and processes proteins that have been made at the ribosomes.
Smooth Endoplasmic Reticulum (SER)		Similar to RER, but with no ribosomes.	Synthesises and processes lipids.
Vesicle		A small fluid-filled sac found in the cytoplasm, surrounded by a membrane	Transports substances in and out of the cell (across the cell membrane), and between organelles. Some are formed by the Golgi Apparatus or the ER while others are formed at the surface
Golgi Apparatus		A group of fluid filled, membrane bound, flattened sacs. Vesicles are often seen at the edges of the sacs.	Processes and packages new lipids and proteins. It also makes lysosomes
Mitochondrion		Usually oval-shaped, they have  a double membrane. The inner membrane is folded to form structures called cristae, inside is the matrix, which contains enzymes involved in respiration.	The site of aerobic respiration where ATP is produced. They're found in large numbers in the cells that are very active and require a lot of energy.
Chloroplast		A small, flattened structure found only in plant cells. It has a double membrane and has membranes inside called thylakoid membranes. These stack up in some parts of chloroplasts to form grana. Grana are linked together by lamellae - thin, flat pieces of the thylakoid membrane.	Where photosynthesis takes place. Some parts of photosynthesis take place in the grana, other parts take place in the stroma (thick fluid found in chloroplasts).
Centriole		Small, hollow cylinders made of microtubules (tiny protein cylinders). They are found in most animal cells, but only some plant cells.	Involved in the separation of chromosomes during cell division.
Cilia		Small, hair-like structures found on the surface membrane of some animal cells. In cross section, they have an outer ring made of pairs of protein microtubules, with two microtubules in the middle. (9+2 formation)	The microtubules allow the cilia to move. This movement is used by the cell to move substances along the cell surface.
Flagellum		Flagella on eukaryotic cells are like cilia, but longer and found in fewer numbers. They stick out from the cell surface and are surrounded by the cell membrane. Inside, they are similar to cilia. They are also in the 9+2 formation.	The microtubules contract to make the flagellum move. The flagellum is used like outboard motors to propel cells forward (Sperm cells).