Nucleic Acid Essay

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Macromolecule: Nucleic Acid Examples: DNA- Its sugar is deoxyribose; its nitrogenous bases are Adenine, Guanine, Cytosine & Thymine; the number of nucleotides in a molecule is more than 45 million; its shape resembles paired strands coiled in a double helix; and its function is to store genetic information that controls protein synthesis. RNA- Its sugar is ribose; its nitrogenous bases are Adenine, Guanine, Uracil & Cytosine; the number of nucleotides in a molecule is between 100 to 50 thousand; its shape varies with hydrogen binding along the length of the strand with three types: mRNA, tRNA & rRNA; and its function is to perform protein synthesis as directed by DNA. Structure: Nucleic acids contain carbon, oxygen, hydrogen, nitrogen and phosphorus with one or two long chains of nucleotides formed by dehydration synthesis. Each nucleotide has three components covalently bound together: a pentose (a five carbon sugar) attached to both ribose (RNA) and deoxyribose (DNA); a phosphate group; and a nitrogenous base (adenine, guanine, thymine, cytosine & uracil-which replaces thymine in RNA). All nucleic acids have two distinctive ends: the 5’ (5-prime) and 3’ (3-prime) ends, which refers to the carbons on the sugar. For both DNA and RNA, the 5' end bears a phosphate, and the 3' end a hydroxyl group. Nucleic acids are synthesized in a 5' to 3' direction. The following diagram represents the general structure of part of a DNA molecule showing its bond type and organisation: Cellular respiration: Aerobic respiration involves a catabolic reaction in which the larger molecules (nucleic acids) are reduced to smaller units (nucleotides) and this occurs in glycolysis. The covalent bonds (high energy bonds) between nucleotides create energy when broken and mostly occur in the cytoplasm. The breakdown requires an enzyme such as adenosine triphosphatase (ATPase-

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