Leanne Butler 02-12-09
Anatomy and Physiology
Introduction to the
The human body is such an interesting machine, the way it is structured and how it works is educational. There is so much to learn about the human body and up until today scientists are still under going medical research. There are a lot of questions people would like to know about how their body works. The report will include the following structures: • Deoxyribonucleic Acid (DNA)
• An Organelle
• The cell membrane
It will also evaluate the functions of the following structures: • The cell
• Body tissue
• Body system
1.1Deoxyribonucleic Acid (DNA)
1.3The Cell Membrane
2.1 The Cell
2.2 Body Tissue
2.3 Body System
3.3 Similarities, benefits and risks of the two procedures 4.1 Cloning
1.1 Deoxyribonucleic Acid (DNA)
Deoxyribonucleic Acid is a molecule, which passes down information, required for the growth, development and reproduction of an organism. It is passed from adults to their children (offspring). DNA is found inside the nucleus of the cell and due to there being a lot of DNA molecules inside a cell; each molecule must be tightly packed. This then becomes a chromosome. DNA found in the cell nucleus is referred to as nuclear DNA, a human’s complete set of nuclear DNA is called its genome. A genome consists of 23 pairs of chromosomes; these chromosomes together consist of 3.1 billion bases of DNA sequence.
DNA consists of chains called nucleotides. Theses are made up of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. The four types of nitrogen bases found in nucleotides are: adenine (A), thymine (T), guanine (G) and cytosine (C). The order or sequence these bases come in, is due to that specific strand of DNA .Each ladder in the DNA is made of two-linked bases. Only (A) and (T) can link together and (G) and (C) can link together. Adenine and Guanine are purines. Purines are double ringed structures. Cytosine and Thymine are singled ringed structures and are known as pyramidines. Each DNA sequence that contains instructions, to make a protein, is known as a gene.
DNA is used to make proteins in a two-step process. Enzymes read the information in a DNA molecule and then transcribe it into an intermediary molecule called messenger ribonucleic acid (RNA), or mRNA. Next the information in the molecules is translated into the “language” of amino acids, which are the building blocks of proteins. (Appendix i)
1.2 An Organelle
An organelle is a discrete structure within a cell, as chloroplast or acentriole. It is characterised by having specialised functions, a usually distinctive chemical composition and an identifying molecule structure: often found in large numbers in aparticular cell. Organelles have specific roles to play in how cells work. Some organelles are separated from the rest of the cell by lipid bi-layers similar in structure to the cell membrane. An example of an organelle is ribosomes. The function of ribosomes is the assembly of proteins, in a process called translation. Ribosomes do this by catalysing the assembly of individual amino acids into polypeptide chains; this involves binding a messenger RNA and then using this as a template to join together the correct sequence of amino acids. (Appendix ii)
1.3 The Cell Membrane
All cells are surrounded by a cell membrane, and its primary purpose is to keep the contents of the cell all together. Cell membranes are like many other organelles of a cell because they exist for a specific job. This job is to monitor and control everything that enters and leaves the cell. The cell membrane is made up of lipid molecules called phospholipids. These molecules all have one polar head and two...
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