Animal Cell Organelles & Their Functions

1.Nucleus – The nucleus generally contains the genetic material for the cell. Because it contains the DNA and chromosomes, which affect the proteins that determine the activities of the cell, the nucleus can be considered to be the cell’s control centre. 2.Cytoplasm – The cytoplasm contains primarily water and protein material. This is where the other cell organelles reside, and where most of the cellular activities take place. 3.Cell Membrane – The cell membrane encloses the cell contents. Its main function is to control what gets into and out of the cell. 4.Ribosomes – Ribosomes are where protein synthesis takes place. Some are attached to the rough endoplasmic reticulum, and some are free in the cytoplasm. 5.Lysosomes – Lysosomes are membrane-bound sacs of enzymes. In a controlled and specific way, they breakdown old or unneeded parts of the cell into small organic molecules that can be reused. 6.Mitochondria – Mitochondria are large organelles where oxygen is combined with food to produce ATP (adenosine triphosphate), the primary energy source for the cell. Mitochondria contain their own DNA, RNA and ribosomes, and can reproduce themselves independently of the cell in which they are found.

7.Golgi apparatus – The Golgi apparatus is composed of small membranous sacs, and is associated with the endoplasmic reticulum (ER). Though its function is still not entirely understood, it seems that proteins from the ER travel to the Golgi apparatus, where they are transformed and packaged into sacs before being moved to their final destination. 8.Smooth Endoplasmic Reticulum – Throughout the eukaryotic cell, especially those responsible for the production of hormones and other secretary products, is a vast network of membrane-bound vesicles and tubules called the endoplasmic reticulum, or ER for short. The ER is a continuation of the outer nuclear membrane and its varied functions suggest the complexity of the eukaryotic cell. 9.Rough Endoplasmic Reticulum – Rough endoplasmic reticulum appears “pebbled” by electron microscopy due to the presence of numerous ribosomes on its surface. Proteins synthesized on these ribosomes collect in the endoplasmic reticulum for transport throughout the cell.

10.Nucleolus – The prominent structure in the nucleus is the nucleolus. The nucleolus produces ribosomes, which move out of the nucleus and take positions on the rough endoplasmic reticulum where they are critical in protein synthesis. 11.Centriole (animal cells only) – Each centriole is a ring of nine groups of fused microtubules. There are three microtubules in each group. Microtubules (and centrioles) are part of the cytoskeleton. In the complete animal cell centrosome, the two centrioles are arranged such that one is perpendicular to the other. 12.Centrosome – The centrosome, or MICROTUBULE ORGANIZING CENTER (MTOC), is an area in the cell where microtubules are produced. Plant and animal cell centrosomes play similar roles in cell division, and both include collections of microtubules, but the plant cell centrosome is simpler and does not have centrioles.