Essay on Cell and Membrane

Submitted By lue2626
Words: 897
Pages: 4

Eukaryotic Organelles | The structure and function | | |

There are many different organelles in eukaryotic cell. Some of the organelles are: the Nucleus, Mitochondria, Ribosome’s, Golgi Apparatus, Lysosome, Endoplasmic Recticulur,Cytoskeleton,Centrioles, Nucleus membrane, and Vacuole. The nucleus is the brains of the cell. The nucleus directs all activities and contains genetic material called chromosomes of DNA. The structure of mitochondria is that it is spherical in shape, and visible when cell is not dividing, and contains RNA for protein manufactor. Mitochondria makes energy out of food. Mitochondria also control level of water other materials in cell. Mitochondria also recycles and decomposes proteins, fats, and carbohydrates, and forms urea. The structure of mitochondria is that it is a doubled-layered outer membrane with inner folds called cristae. Energy-producing chemical reactions take place on cristae. Ribosome’s make protein. Ribosomes compose of 25% of cell’s mass. The stationary type is embedded in rough endoplasmic reticulum. Golgi apparatus makes, process, and package proteins. Golgi apparatus is a membrane structure found near the nucleus. It is composed of numerous layers forming a sac. Lysosome’s ‘plant’ for proteins, lipids, and carbohydrates with digestive enzymes to help break down food. Endoplasmic Reticulum is a tubular network fused to the nuclear membrane. Endoplasmic reticulum is called the “intracellular highway” because it is for transporting all sorts of items around the cell. Endoplasmic reticular goes through cytoplasm onto cell membrane. Endoplasmic reticular also stores and separate. Smooth type endoplasmic reticular lacks ribosomes. Rough type endoplasmic reticular has ribosome’s embedded in the surface. Vacuole is a membrane-bound sacs used for storage, digestion, and waste removal. Vacuoles usually contain water solution or food. Chloroplasts use sunlight to create food by photosynthesis. The cell wall is for support. Chloroplasts also contain green chlorophyll. The cell wall is most commonly found in plant cells. It controls turgity. The cell wall has extracellular structure surrounding the plasma membrane. The cell wall is extremely elastic. The cell wall has a secondary wall that forms around the primary wall after growth is complete. Organelles with a definite boundary created by a membrane are called membranous organelles. Nucleus, Golgi apparatus, mitochondria, lysosomes, endoplasmic reticular, and vacuoles are membranous organelles. Non membranous organelles are ribosome’s and parts of the cytoskeleton. The membrane is important because it is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substance in and out cells. The main function of the membrane is to protect the cell from its surroundings. Cell membranes are also important because they are involved in a variety of cellular processes such as cell adhesion, ion conductivity, and cell signaling. Another importance of the membrane is that it serves as the attachment surface for several extracellular structures such as the cell wall, glycocalyx, and intracellular cytoskeleton. Cell membranes can also be artificially reassembled. Another important factor of the membrane structure is that cellular membranes were the structures to evolve. The cell membrane is the only cellular structure that is found in all of the cells of all the organisms on earth. Separating vital chemicals and structures needed to maintain the cell from the environment, which may contain chemicals and structures that are harmful to the cell. Cell membranes also contain structures that help regulate the types and amounts of molecules pulled from the environment. The structure of the membrane is often referred to as “Fluid Mosaic Model.” It is called fluid mosaic model because of the way that it is…