Chapter 3 Biochemistry

I. Carbon Compounds Inorganic vs. Organic Inorganic compounds do not contain carbon atoms Organic compounds contain carbon atoms

Carbon Bonding Carbon has 4 electrons in its outer shell It wants to gain 4 more to become stable with 8 Carbon readily forms four covalent bonds with atoms of other elements Carbon is unique from other elements because it can bond with other carbon atoms Because of all the preceding, carbon is able to form an enormous variety of organic bonds

Single Bond-sharing one pair of electrons Double Bond-sharing two pair of electrons Triple Bond-sharing three pair of electrons

Functional Groups Clusters of atoms that influence the properties or characteristics of the molecule

Large Carbon Molecules Monomers- a simple molecule, smallest subunit Polymers- made of repeating monomers Macromolecules- made up of large polymers

Condensation Reactions- release a molecule of water to form a bond

Hydrolysis- water is added to break a polymer

You Down with ATP? Cells run on energy in the form of ATP Adenosine triphosphate Phosphate groups attached by covalent bonds, which store high amounts of energy

II. Molecules of Life Carbohydrates Lipids Proteins Nucleic Acids

Carbohydrates Composed of carbon, hydrogen, and oxygen in a ratio of 1C:2H:1O, Serve as a source of energy or used for structural materials Monosaccharides- a monomer of a carbohydrate (glucose, fructose and galactose) Disaccharides- two monosaccharides or a double sugar (glucose + fructose = sucrose) Polysaccharides- three or more monosaccharides

Animals store glucose in the form of the polysaccharide glycogen Plants store glucose as the polysaccharide starch Strength and rigidity in plants is caused by the structure of the polysaccharide cellulose

Proteins Composed mainly of carbon, hydrogen, oxygen, and nitrogen, provide structure for cells Amino acids-monomers of protein (building blocks) Dipeptides-two amino acids held together by a peptide bond Polypeptides- three or more amino acids, held together by peptide bonds

Amino Acids 20 different amino acids All contain Central carbon Amino group A carboxyl group (COOH) A single hydrogen R group (the only thing different between the 20 amino acids) influences the properties of the amino acid

Peptide Bond Covalent bond linking two amino acids A condensation reaction (water is formed and released) Long chains of amino acids has positive and negative regions which fold to give protein molecules unique shapes The shapes can be denatured when heated

Enzymes RNA or protein molecules that act as biological catalysts Depend on the fit between Substrate Enzymes active site

Lipids Long chains of carbon with many hydrogens Function is to store energy Include: fatty acids, triglycerides, phospholipids, waxes, steroids

Fatty Acids Unbranched carbon chains that make up most lipids Long chain of carbon with a carboxyl group at one end Carboxyl end is polar and therefore hydrophilic Hydrocarbon end is nonpolar and therefore hydrophobic Fatty acids include triglycerides, phospholipids, and waxes

Unsaturated Fatty Acids Carbon atoms fully saturated with hydrogens Unsaturated Fatty Acids Carbon atoms with double bonds

Triglycerides 3 molecules of a fatty acid joined to one molecule of the alcohol glycerol Saturated triglycerides have high melting points and are hard at room temp (butter and fats in red meat) Unsaturated are usually soft or liquid at room temp and found in plant seeds (olive oil)

Phospholipids Two fatty acids attached to a molecule of glycerol and a phosphate group attached to the third carbon of the glycerol Help make up the cell membrane Lipid bilayer Hydrophobic head Hydrophilic tail

Waxes A long fatty acid chain connected to a long alcohol chain Waterproof Help form protective coating in plants and animals (earwax)

Steroids Four fused carbon rings with various functional groups Hormones Cholesterol

Nucleic Acids DNA RNA Composed of nucleotides Contains information that determines the characteristics of an organism and directs cell activities RNA Stores and transfer information of DNA to make proteins Composed of nucleotides Sugar Phosphate Base

Review What do all organic compounds contain? Carbon

How many electrons are shared in a double bond? 4 electrons (aka 2 pair)

How many electrons does carbon want to gain? What is the smallest subunit 4 electrons Monomer

What is the monomer of carbohydrates? What is the monomer of proteins? monosaccharides What is the monomer of proteins? Amino acid

How do animals store glucose? How do plants store glucose? Glycogen How do plants store glucose? Starch

What are the polymers of carbohydrates polysaccharides What are the polymers of protein? Polypeptides

What are the only two macromolecules that contain nitrogen? Proteins Nucleic Acids Which macromolecule is nonpolar? Lipids