Nucleic acids information molecules storage for

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Nucleic Acids - Information molecules - Storage for information in cells - DNA & RNA - Can produce exact copies of them Structures of Nucleic Acid Nucleic acids are long polymers of repeating subunits called Nucleotides. - There are 3 components of a Nucleotide: 1. A five-carbon sugar 2. A Phosphate group (— PO 4 ) 3. An organic nitrogenous base - When a nucleic acid polymer forms, the phosphate group of one nucleotide binds to the hydroxyl group of another, releasing water and forming a phosphodiester bond . - A nucleic acid , then, is simply a chain of five- carbon sugar linked together by phosphodiester bonds with an organic bass protruding from each sugar . Two Types of Organic Bases: Ø Purines – are large, double-ring molecules found in both DNA and RNA; they are Adenine (A) and Guanine (G) . Ø Pyrimidines – are smaller, single-ring molecules; they include Cytosine ( C , in both DNA and RNA), Thymine ( T , in DNA only), and Uracil ( U , in RNA only) Deoxyribonucleic Acid (DNA) - Hereditary material - Has a double helix structure (double stranded) - In each of its steps are complimentary base pairs attracted by hydrogen bonds . Ribonucleic Acid (RNA) - Responsible for protein synthesis - Singe stranded The Ultimate Face-Off! (DNA vs. RNA) 1. DNA contains deoxyribose sugar while RNA contains ribose sugar in which the #2 Carbon is bonded to a hydroxyl group. In DNA, this hydroxyl group is replaced by a hydrogen atom. 2. RNA utilizes Uracil in place of Thymine. Uracil has the same structure as Thymine, except that one if its carbons lacks methyl group (—CH 3 ). 3. DNA is double stranded while RNA is single stranded 4. They obviously has different functions Why Do we Need To Transcribe DNA Message? - This allows cell to tell which is the original information storage molecules and which is the transcript Lipids - Insoluble in water - Most familiar lipids are fats and oils - Have a very high proportion of nonpolar
carbon-hydrogen (C—H) bonds - They don't fold like a protein instead, when placed in water many lipid molecules will spontaneously cluster together and expose what polar groups they have. Phospholipids Form Membranes - Phospholipids are among the most important molecules of the cell, as they form the core of all biological membranes. - An individual phospholipid is a composite molecule, made up of 3 kinds of subunits: 1. Glycerol , a three- carbon alcohol, with each carbon bearing a hydroxyl group. It forms the backbone of the phospholipid molecule . 2. Fatty acids , long chains of C—H bonds (hydrocarbon chains) ending in a carboxyl group (—COOH). Two fatty acids are attached to the glycerol backbone in a phospholipid molecule. 3. Phosphate group , attached to one end of the glycerol. The charged phosphate group usually has a charged organic molecule linked to it , such as Choline, Ethanolamine, or the amino acid Serine. - The phospholipid molecule can be thought of as having a polar “head” at one end ( phosphate group ) and two long, very nonpolar “tails” at the other.

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