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Large Molecules Are Important In the Structure And Functioning Of Cells

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Large Molecules Are Important In the Structure And Functioning Of Cells Large biological molecules are found in all cells, in plant and animals cells too. There are many different large biological molecules such as carbohydrates, proteins, lipids, nucleic acids which are all extremely important to the functioning and structure of living cells. We would not be alive if any of these groups were missing. This signifies their importance. Carbohydrates contain three elements. Carbon (C), Hydrogen (H) and Oxygen (O) Carbohydrates are found in three forms. Monosaccharide, Disaccharides (both sugars), and Polysaccharides. Disaccharides and glycosydic bonds are formed when two monosaccharide are condensed together. One monosaccharide loses an H atom from carbon atom number 1 and the other loses an OH group from carbon 4 to form the bond. The reaction, which is called a condensation reaction, involves the loss of water (H2O) and the formation of a 1, 4-glycosidic bond. Depending on the monosaccharide used, this can be an ?-1, 4-glycosidic bond or a ?-1, 4-glycosidic bond. ...read more.


When 2 amino acids are joined together (condensation) the amino group from one and the acid group from another form a bond, producing one molecule of water. The bond formed is called a peptide bond. Primary structure of proteins The primary structure depends on the order and number of amino acid For e.g. Haemoglobin is made up of 4 polypeptide chains, each with a haemoglobin group attached. There are 146 amino acids in each chain. If just one of these is wrong, serious problems can arise (e.g. sickle cell anaemia). Secondary structure of proteins This is the basic shape that the chain of amino acids takes on. The 2 most common structures are the a-helix and the b-pleated sheets in a particular protein. This has a regular coiled structure like a spring, with the R groups pointing towards the outside of the helix. Hydrogen (H) bonds are relatively weak but because there are so many, the total binding effect is strong and stable. ...read more.


Structure of DNA. DNA is a polymer of nucleotides: are made up of a phosphate, a sugar - deoxyribose, a base - adenine, guanine, thymine or cytosine. In DNA the sugar is always the same but each nucleotide will have only of the four nitrogenous bases. The phosphate sugar and base are linked together. DNA is a macromolecule polymer made of subunits called nucleotides. The nucleotides are arranged in two chains which are coiled into a spiral shape called a double helix. As with all nucleotides, those in DNA have three parts. These are a pentose sugar called deoxyribose, a phosphate group and a nitrogenous base. The sugar and the phosphate are exactly the same in every nucleotide, but the base varies. There are four bases in DNA and each nucleotide contains one of them. The bases are called Adenine, Guanine, Thymine and Cytosine. (A,G,T and C for short). The order of the nucleotides means that the bases they contain are in a certain order, it is this order which forms the genetic code. Words 1000 exactly. ...read more.

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