Organelles and their Functions

Animal Organelle Functions

Nucleus: Largest organelle. The nucleus controls DNA (Deoxyribonucleic acid ) and controls all cell activities. The nucleus contains a double membrane,  Nucleolus: The nucleolus controls the synthesis of RNA and other components. The nucleolus is needed to build ribosomes. This organelle is located in the Nucleus.   Nuclear Pores: These pores allow mRNA and rRNA to be actively transported out of the nucleus, and nuclear proteins to be transported in.  Plasma Membrane: Controls the entry and exit of materials  Cytoplasm: Contains cell organelles. The cytoplasm is also the site of chemical reactions within a cell.  Ribosome:  Site of protein synthesis (Translation)  Rough Endoplasmic Reticulum (RER):  This organelle has ribosomes attached to the surface. The organelle is the place where proteins are modified and transported. This organelle is membrane bound.  Smooth Endoplasmic Reticulum:   No ribosomes on the surface, unlike RER. This organelle synthesises lipids and steroids.  Golgi Apparatus: A tightly packed group of flattened fluid-filled sacs.  The Golgi Apparatus processes and packages complex molecules ready for discharge from the cell. This organelle is bound by a membrane.  Mitochondrion: A large organelle; is the site of aerobic respiration which makes ATP. The mitochondrion has a double membrane, the outer smooth, the inner folded to give a large surface area.  Lysosomes: Contain digestive enzymes which break down worn out cell structures and foreign particles by phagocytosis.  Vacule: Stores materials that may stay in the cell or be released. The Vacule is membrane bound.  Centrioles:  Centrioles are close to the nucleus. They are in the centre of the centrosome or microtubule organising centre (MTOC). They duplicate just before cell division and form the basis of the spindle  Secretory Vesicle:  Vesicle fuses with the plasma membrane, releasing materials to be secreted from the cell.       

Plant Cell Organelle Functions

Note: The organelles that have already been talked about in the "Animal Organelle Functions" that are present in the plant cell will not be mentioned here. Only the organelles that have not been mentioned within plant cells will be covered.    Cell wall: The cell wall supports the cell and forms the shape of the plant cell Chloroplasts:   Green structures which contain chlorophyll. Chlorophyll is needed for plants for photosynthesis. Chloroplast is bound by a membrane  Vacuole: Contains sap, which is a solution of sugars and salts. It also stores excess water. 

Bacterial Cell Organelle Function

DNA (Nucleoid):  Contains genetic information for the cell. DNA is in a single (but very loopy) molecule called a nucleoid.  Plasmid: A small circular piece of DNA that is passed from bacterial cell to bacterial cell. A plasmid is also extra DNA. Capsule: A capsule or slime layer around their wall. It's made of a sticky polysaccharide. This makes them extra sticky and gives protection against enzymes, phagocytes and antibodies - Very helpful for the ones that make you sick.  Flagellum: Bacteria move towards things they like (food) or away from things they don't (Toxins) with a flagellum. Pili:  This helps bacteria stick to stuff like you. It also helps the bacteria stick to one another so they can swap plasmids.