Cells essays

Cells essays Proteins made from ribosomes attached to the rough endoplasmic reticulum enter the lumen of the ER and move to the smooth endoplasmic reticulum. A small vacuole (vesicle) pinches off the smooth ER and carries the protein to the Golgi apparatus, where it is further processed. Mitochondria are bounded by a double membrane. The inner membrane is folded to form little shelves, called cristae, which project into the matrix, an inner space filled with a gel-like fluid. A vacuole is a large membrane-enclosed sac that usually functions as a storage area. Plant vacuoles contain not only water, sugars, and salts but also pigments and toxic substances. The pigments are responsible for many of the red, blue, or purple colors of flowers and some leaves. The green pigment chlorophyll, found within the grana, makes chloroplasts and leaves green. Chlorophyll absorbs solar energy, and chloroplasts convert this energy into ATP molecules. Chloroplasts carry on the process of photosynthesis, in which light energy is used to produce food molecules, such as glucose. Chloroplasts take in carbon dioxide, water, and solar energy in order to produce glucose and oxygen. The energy-related organelles, chloroplasts and mitochondria, convert one form of energy into another. While chloroplasts are unique to plant cells, mitochondria are found in both plant and animal cells. Chloroplasts carry on photosynthesis, during which light energy (photo) is used to produce food molecules, like glucose (synthesis). Chloroplasts take in carbon dioxide, water, and solar energy in order to produce glucose and give off oxygen. Mitochondria are often called the powerhouses of the cell: just as a powerhouse burns fuel to produce electricity, the mitochondria convert the chemical energy of glucose products into the chemical energy of ATP molecules. Chromatin, a threadlike material, contains DNA and is found within the nucleus. At the time of cell division, chromatin conde...