Organisation of the body Essay Example | Topics and Well Written Essays - 1750 words

Organisation of the body - Essay Example It has several functions, including; the control of DNA replication and gene expression, prevention of damage to DNA, enhancing mitosis by strengthening DNA, and packaging DNA strands to fit in nucleus (Lloyd & Beck, 2012: p27). This entails a network of membranes or tubes that connect the cellular membrane to the nuclear envelope. Involved in the metabolism of steroids and carbohydrates, synthesis of steroids and lipids, and receptor attachment on proteins of the cell membrane (Lloyd & Beck, 2012: p41). This is an endoplasmic reticulum studded on the outer surface with attached ribosomes, compared to SER that have none. These ribosomes manufacture proteins and deposit them in the lumen of the RER, after which they are transported as vesicles to the Golgi complex (Lloyd & Beck, 2012: p41). A stack of flattened compartments or sacs that receive proteins from the RER, which is crucial in the transport and modification of proteins. It is involved in the modification, packaging, and export of proteins to other cell organelles, such as the mitochondria, or for secretion by the cell (Lloyd & Beck, 2012: p43). They are tail-like projections found in prokaryotes and eukaryotes and protrude from their cell body. They are longer than cilia, but fewer in number, and their major function is locomotion through whip-like movements that propel the cell through liquid matter (Lloyd & Beck, 2012: p32). These are peanut-shaped organelles with double membranes, whereby the inner membrane is folded to form cristae. Aerobic cellular respiration occurs here, as well as the breakdown of sugar molecules for production of energy in the form of ATP (Lloyd & Beck, 2012: p19). This is a large, oval organelle, which has at least one nucleolus and contains DNA. It also holds the cell’s hereditary material. Its main function is to control the activities of the cell, particularly with regards to reproduction,