As with all living cells, eukaryotic cells must produce energy in the form of ATP molecules. Typically, glucose is the molecule that is frequently used. The initial breakdown of glucose will occur in the cytoplasm of the cell. The products of this breakdown, two pyruvic acid molecules, will then be transported to the mitochondria. There the process of cellular respiration will be completed to create ATP.
Only those eukaryotic cells with chloroplasts are able to conduct photosynthesis. Light energy is collected by the chlorophyll in the chloroplast to create high energy electrons. These electrons are used to produce ATP and NADPH (a carrier of high energy electrons). ATP and NADPH are then used convert carbon dioxide into glucose and other compounds. This portion of photosynthesis takes place in the stroma of the chloroplast.
All cells must be able to create proteins in order to function properly. In eukaryotes, protein synthesis requires DNA, RNA, ribosomes, and enzymes. Simply put, the DNA contains the information to create the protein. Messenger RNA is created in the nucleus to take this information out into the cytoplasm. Once there, the messenger RNA joins with a ribosome (ribosomal RNA). Together with transfer RNA bringing in the amino acids (building blocks for proteins), assembly of the protein is done. Typically, it will then be transported to the Golgi apparatus, since each protein needs to be modified in some way before it is useful to the cell.
Cells will continue to grow until they reach a point where nutrient intake and waste output becomes difficult. This point is based on the surface area to volume ratio of the cell. Typically, cells will undergo the process of division in order to survive. In eukaryotic cells, cell division is referred to as mitosis (Lesson 3.4). Plants and animals both require DNA, RNA, enzymes, and other proteins for this process. Animal cells also require centrioles. Plant cells do not.
The cell’s DNA must double prior to the actual division of the cell into two. The doubled DNA must undergo a series of steps to be correctly segregated and separated. The end result, if all goes to plan, is two cells that are genetically identical to one another.