Chapter 3 - Biochemistry Section 2: Carbon Compounds

Carbon Bonding Organic Compounds: made mostly of carbon atoms Inorganic Compounds: do not contain carbon Carbon can bond with itself: It can form straight chains It can form branched chains It can form rings

Functional Groups Functional groups are the portion of a molecule that gives the molecule it’s particular properties. They are also active in a chemical reaction.

Carboxylic Acids Carboxyl Hydroxyl Carbonyl Amino Sulfhydryl Functional Group Formulas/ Chemical Structures Common Name Biological Importance Carboxylic Acids Polar – water soluble Acid in Amino Acids Act as buffers in organisms Carboxyl Alcohols: Methanol, Ethanol Polar – whole molecule is water soluble Hydroxyl Aldehydes Glyderaldehyde Formaldehyde Ketones Acetone Polar – water soluble Functional group in carbohydrates Metabolic intermediates Ketones = nonpolar Carbonyl a. Aldehyde b. Ketone Amines Amino Acids - Glycine Polar Found in amino acids Ammonia waste from protein Amino Cystine (amino acid) Stabilizes proteins Sulfhydryl Polar; Acidic Found in DNA/RNA Used in energy transport (ATP) Organic Phosphates Phosphate

Large Carbon Molecules Monomers: building blocks of organic molecules Polymer: molecule made of multiple monomers that are linked together Macromolecules: large polymers Ex: carbohydrates, lipids, proteins and nucleic acids

Making and Breaking Polymers Condensation Reaction: monomers are linked to polymers and water is released Hydrolysis: break down of polymers using water The reverse of a condensation reaction

Energy Currency Life processes require a constant supply of energy Adenosine Triphosphate (ATP) a high energy compound found in cells Covalent bonds hold the phosphate groups together The bond that attaches the last phosphate group to the rest of the molecule is easily broken releasing energy for cell work

Chapter 3 - Biochemistry Section 3: Molecules of Life

Molecules of Life 4 Molecules of Life Carbohydrates (sugars) Proteins (enzymes) Lipids (fats) Nucleic Acids (DNA and RNA)

Carbohydrates Carbohydrates are organic compounds composed of carbon, hydrogen and oxygen General ratio is 1C:2H:1O or (CH2O)n Monosaccharides: monomer (building block) of a carbohydrate Examples: Glucose, Fructose and Galactose All 3 monomers have the same formula  C6H12O6, but they each have different structures - isomers Glucose Fructose

Carbohydrates Disaccharides: double sugar (two monosaccharides bonded together) The reaction that joins the two monosaccharides together is called a condensation reaction Examples: Sucrose Lactose Sucrose

Carbohydrates Polysaccharides: made of 3 or more monosaccharides bonded together Examples: Glycogen (in animals): energy storage Stored in liver and muscle, made of glucose molecules Starch (in plants): energy storage Made of glucose molecules Cellulose (in plants): used for structure  cell wall

Proteins Proteins are organic compounds made of carbon, hydrogen, oxygen and nitrogen Monomer = amino acids 20 different amino acids Functional groups of amino acids: -COOH, NH2 What gives the amino acid its specific identity is it’s R-group R-groups can be simple or complex

Proteins Dipeptides are two amino acids bonded together The bond between amino acids is called a peptide bond Peptide bonds are formed during a condensation reaction

Proteins Polypeptides: very long chains of amino acids Form larger proteins, which are usually made of more than one polypeptide chain 4 levels of structure for polypeptides Primary: linear sequence of amino acids Secondary: polypeptide forms α-helices and β-sheets Tertiary: R-groups interact with one-another Quaternary: more than one polypeptide chain making a protein

Proteins Enzymes: Protein (or RNA) molecules that act as biological catalysts How enzymes work: Induced Fit Model of Enzyme Action Enzyme reactions depend on the physical fit between the enzyme and its substrate (the reactant being catalyzed) Active Site: portion of the enzyme that the substrate fits into The linkage between the enzyme and the substrate causes a slight change in the enzyme’s shape which puts a strain on the substrate bonds The enzyme releases the products and remains unchanged Temperature and pH effect an enzyme’s activity

Enzyme Action http://www.biotopics.co.uk/other/hienz.html

Lipids Lipids: large, nonpolar organic molecules DO NOT dissolve in H20 Building blocks of lipids: Glycerol: Functional group = -OH Fatty Acids: unbranched carbon-chains Functional group = -COOH

Lipids Fatty Acids Continued: Fatty acids can be saturated (each carbon is bonded to 4 other things – “full”) Fatty acids can be unsaturated (when the carbon atoms form double bonds with each other in the carbon chain)

Lipids Types of Lipids: Triglycerides: 3 fatty acids attached to a glycerol Phospholipids: 2 fatty acids attached to a glycerol, with a phosphate attached to the 3rd carbon of the glycerol Makes-up the cell membrane of cells Hydrophilic head 2 Fatty acid tails

Lipids Types of Lipids Continued Waxes: Steroids: Structural lipids Fatty-acid chains connect to an alcohol chain Water-proof and provide protection Steroids: Made of 4 fused carbon rings Functions Hormones (testosterone) Found in cell membranes (cholesterol)

Nucleic Acids Nucleic Acids: store and transfer genetic information 3 parts of a nucleic acid: Phosphate Group Sugar Nitrogenous Base Three combined forms the nucleotide 2 types of Nucleic Acids DNA: stores genetic information for an organism RNA: stores and transfers information from DNA that is needed to make proteins