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Biochemistry. Chapter 3. The element carbon is a component of almost all biological (organic) molecules . Carbon has 4 electrons in its outermost energy level. Carbon compounds can be straight chains, branched chains, and rings.
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Biochemistry Chapter 3
The element carbon is a component of almost all biological (organic) molecules.
Carbon has 4 electrons in its outermost energy level. • Carbon compounds can be straight chains, branched chains, and rings.
Carbon can share 1, 2, or 3 pairs of electrons with another atom • Functional groups influence molecule characteristics Hydroxyl –OH O Carboxyl –C-OH H Amino N-H O Phosphate -O-P-OH OH
Macromolecules large molecules formed by joining smaller organic molecules • Polymersmolecules made from repeating units of identical or nearly identical compounds linked together by covalent bonds
Condensation Reaction-water is released each time a monomer is added to a polymer • Hydrolysis-water breaks down a polymer • Reverse of each other
Energy Currency • adenosine triphosphate-ATP • Bonds between the phosphate groups are less stable • When bond is broken, (hydrolysis) energy is released
Carbohydrates • Compounds composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom—(CH2O)n
Values of n ranging from three to seven are called simple sugars, or monosaccharides. • Two monosaccharides joined together form a disaccharide. • Longer carbohydrate molecules are called polysaccharides.
Proteins • A compound made of small carbon compounds called amino acids
Amino acids have a central carbon atom. • One of the four carbon bonds is with hydrogen. • The other three bonds are with an amino group (–NH2), a carboxyl group (–COOH), and a variable group (–R).
The number and the order in which the amino acids are joined define the protein’s primary structure. • After an amino acid chain is formed, it folds into a unique three-dimensional shape, which is the protein’s secondary structure, such as a helix or a pleat.
Lipids • Molecules made mostly of carbon and hydrogen • A triglyceride is a fat if it is solid at room temperature and an oil if it is liquid at room temperature. • Lipids only single bonds - saturated fats. • Lipids at least one double bond - unsaturated fats. • Fats more than one double bond - polyunsaturated fats.
Phospholipids • Made of a glycerol, phosphate group and 2 fatty acid chains • 2 layers of these-bilayer-makes up cell membranes
Nucleic acids - complex macromolecules that store and transmit genetic information-DNA, RNA • Nucleic acids are made of smaller repeating subunits called nucleotides, made of carbon, nitrogen, oxygen, phosphorus, and hydrogen