Take a Tour of the Animal Cell

All living things are made up of cells. There are two types of cells, which are referred to as prokaryotic and eukaryotic cells. Animals have eukaryotic cells. Eukaryotic cells are different from prokaryotic cells (ex. bacteria) because eukaryotic cells have a nucleus and membrane bound organelles. Organelles are subcellular structures that carry out a certain function in the cell. Inside the cell, there is an endomembrane system. The functions of this endomembrane system are to regulate protein traffic and to perform metabolic functions in the cells. The following organelles are part of the endomembrane system: nuclear envelope, endoplastic reticulum, golgi apparatus, lysosomes, and the plasma membrane. These components of the animal cell and the other components of the animal are described in further detail below.

1. Cell Membrane
The cell membrane consists of the phospholipid bilayer along with many types of proteins and cholesterol. The function of the cell membrane is to control movement in and out of the cell.

2. Cytoplasm
The cytoplasm consists of cytosol that surrounds the cell's organelles. The function of the cytoplasm is to house metabolic activity.

3. Ribosomes
The ribosomes function in a cell is protein synthesis. Ribosomes can either be free in the cytosol or bound to the outside of the nucleus or the endoplastic reticulum.

4. Cytoskeleton
The cytoskeleton is the structural framework of the cell. The cytoskeleton consists of the microtubules, microfilaments, and intermediate filaments. The functions of the cytoskeleton include maintaining cell shape and facilitating cell mobility. The cytoplasm also anchors down the organelles of the cell.

5. Nucleus
The main function of the nucleus is to store DNA. The nucleus stores all genes present in the organism's genome. However, only certain genes are expressed according to the cell's function and needs.

6. Nucleolus
The nucleolus is located in the nucleus. This is where ribosome synthesis takes place.

7. Endoplastic Reticulum (ER)
There are two types of ER: rough and smooth. The smooth ER does not have ribosomes and participates in fatty acid synthesis and phospholipid synthesis. The rough ER has ribsomes and participates in mRNA processing.

8. Golgi Apparatus
The golgi apparatus is involved in processing, synthesizing, and packaging macromolecules in the cell.

9. Peroxisome
The peroxisome processes hydrogen peroxide. Hydrogen peroxide can be very harmful to the cell.

10. Mitochondria
The mitochondria are considered to be the powerhouse of the cell. This is the site of cellular respiration which generates ATP. ATP is the energy supplier to the cell.

11. Lysosomes
The lysosome in the cell digests macromolecules. Lysosomes have special digestive enzymes to catalyze these macromolecules.

Sources

Campbell, Neil, and Jane Reece. Biology. 7th ed.. San Francisco: Pearson, 2005. Print.