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Organic Molecules of Life. Organic molecules :. are compounds created by living organisms contain the elements carbon and hydrogen. Carbon atoms:. need four electrons to fill their outer electron shell Must form four bonds with other elements. These are covalent bonds.
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Organic molecules : • are compounds created by living organisms • contain the elements carbon and hydrogen
Carbon atoms: • need four electrons to fill their outer electron shell • Must form four bonds with other elements. • These are covalent bonds. • Most often bond with Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur, and other Carbon atoms 6 P 6 N
These can include: • Single bonds (one electron shared) • Double bonds (two electrons shared) • Or triple bonds (three electrons shared)
Carbon Atoms: Can bond with other atoms of carbon to form long chains These chains can be: Straight Branched Rings
Isomers • Molecules with the same formula • Atoms are arranged differently • Carbons are branched in various ways
Functional groups: • Are special groups of atoms that stay together and act as a single unit • can bond with the carbon chains • determine how the entire molecule will react.
Hydroxyl Group • one oxygen and one hydrogen • usually written as • -OH Oxygen Hydrogen
Carboxyl Group • one carbon with a double bond to an oxygen AND a single bond to a hydroxyl group • usually written as COOH or O=C–OH • Creates an organic acid (carboxylic) Oxygen Carbon Oxygen Hydrogen
Amino Group • one nitrogen bonded to two hydrogen • usually written as NH2 or H–N–H Hydrogen Nitrogen Hydrogen
Phosphate Group: • One phosphorus bonded to two hydroxyl groups, and two other oxygens (one has a double bond) • Usually written as –P or OH O P O OH Phosphorus
These large molecules are built from basic units called monomers. One monomer
The monomers are linked together to form the large molecules called polymers. Polymer – chain of repeating monomer units
Making and Breaking Polymer Bonds Monomers When two monomers are put together to form larger molecules, a water molecule is created. Polymer
This process is called: Dehydration Synthesis. (Dehydration means to lose water Synthesis means to build or put things together)
When polymers are broken apart, it is done by adding a water molecule.
This is called Hydrolysis (hydro- for water, -lysis for breaking apart)
Types of Organic Molecules There are four categories of organic molecules in organisms: Carbohydrates Lipids Proteins Nucleic acids
What are Carbohydrates? • Organic compounds • Commonly called starches and sugars • Used as: • An energy source • Energy storage • Cellular structures
Chemical Composition • Contains only three elements: • Carbon • Hydrogen • Oxygen • Ratio of hydrogen to oxygen is 2:1(just like water) Example: C6H12O6 • Basic Unit is called a saccharide
Types of Carbohydrates • Monosaccharides • Simple, single (mono-) sugar unit • Building block of all other carbohydrates • Name usually ends in –ose • Used as energy source
Examples of Monosaccharides • Glucose – blood sugar • Fructose – fruit sugar • Galactose – one monomer in lactose (milk) Isomers of C6H12O6
Examples of Monosaccharides • Ribose and Deoxyribose • 5 - Carbon sugars in RNA and DNA
Types of Carbohydrates • Disaccharides • Double sugar units synthesized from monosaccharides • All are isomers of C12H22O11 • Formed by dehydration synthesis (requires enzymes)
Examples of Disaccharides • Sucrose – table sugar Glucose + Fructose • Maltose – seed sugar Glucose + Glucose • Lactose – milk sugar Glucose + Galactose
Types of Carbohydrates • Polysaccharides • Large, complex chains of many (poly-) repeating sugar units • Polymers • Bonded together by dehydration synthesis • Used by living things as a sugar storage or for structures
Examples of Polysaccharides • Amylose – plant starch • Used as sugar storage in seeds, roots, stems • Glycogen – animal starch • Used as sugar storage by humans in the liver • Cellulose • Very tough polymer • Used as a main component of cell walls • Indigestible by humans • Chitin • Very tough polymer • Used in exoskeletons (crab shells, insects)
Digesting Polysaccharides • Broken apart by hydrolysis with the help of enzymes
What are Lipids? • Three elements: Carbon Hydrogen Oxygen • Ratio of H:O much greater than 2:1 • Example: Oleic acid C18H34O3 • Insoluble in water • Greasy, slippery texture • Three main groups: • Fats oils and waxes • At room temperature: Liquid – oils/Solid – fats and waxes • Phospholipids • Steroids
What are the Functions of Lipids? Fats, Oils and Waxes: Long term energy storage • More than twice as much energy stored than carbohydrates • fats- 9 Calories/gram; carbohydrates- 4 Cal/g • In plants: stored in and around seeds • Peanut oil, corn oil, olive oil • In animals: stored under the skin and around internal organs • Used as insulation and shock absorber
What are the Functions of Lipids? • Phospholipids • Structural Part of Cell membranes • Steroids • Part of cell membranes, transport of lipids, regulate body functions (hormones)
Chemical Composition Fats Oils, Waxes • One or more fatty acids attached to a Glycerol backbone • Fatty Acids: Long chains of carbon with a carboxyl group at the end • Glycerol: C3H8O3 • Formed by dehydration synthesis • NOT a polymer Fatty Acid Glycerol Glycerol Lipid
Types of Fats • Saturated • All carbons of the fatty acid have single bonds • All carbons are “filled” with hydrogen • Solid at room temperature • Associated with heart disease risk • Examples: Bacon grease, butter
Types of Fats • Unsaturated • Carbons share one or more double or triple bonds with other carbons • Monounsaturated – only one double bond • Polyunsaturated – many double or triple bonds • Liquid at room temperature • Examples: corn oil, olive oil
Phospholipids • Phosphate group replaces fatty acid on one end • Used as the main component of cellular membranes
Steroids: Four Fused Rings • lipids with four fused hydrocarbon rings • Includes: • Cholesterol - found in animal cell membranes • Testosterone, estrogen, progesterone - sex hormones • Vitamin D • An anabolic steroid is a synthetic testosterone.
Protein Functions • Structural parts • cell membrane, muscles, hair, nails, pigments • Regulators • Hormones, enzymes • Carriers • Transport materials in, out and around cells • Identification • Allow cells to recognize each other • Immune system antibodies
Composition of Proteins • Elements: • carbon, hydrogen, oxygen and NITROGEN • Very large, complex • Hemoglobin: C3032H4816O872N780S8Fe4 • Monomers (building blocks) are amino acids • 20 common amino acids • 9 are essential 11 are non essential
Amino Acids The R group is different for each of the twenty amino acids
Peptide Bonds • Chains of amino acids are called peptides • Amino acids are joined by dehydration synthesis • This occurs between the carboxyl end of one amino acid and the amino end of another amino acid. • The resulting bond is called a Peptide bond
Primary Structure • The sequence of amino acids in a protein is called the Primary Structure • The sequence is unique for each protein and is determined by the DNA
Secondary Structure • Hydrogen bonds are formed between the chains of amino acids causing different shapes.
Secondary Structure Two shapes are common – a helix and a sheet. Sheet and Helix