Organic Molecules
Organic Chemistry The chemistry of the living world. Organic Molecule a molecule containing carbon and hydrogen Carbon has 4 electrons in its outer shell and can share electrons with atoms of up to 4 different elements, leading to a variety of carbon compounds. Most often shares with C, H, N, O, P, and S
The Carbon Atom (cont.) Because the carbon atom s outer shell has four electrons, it can bond with up to four other elements total =8 OCTET RULE. Carbon atoms frequently bond with other carbon atoms, forming chains called hydrocarbons. Some carbon molecules, called isomers, have the same number and kinds of atoms but in different arrangements.
Carbon Atoms P. 31
Hydrocarbons P. 31
Organic Chemistry cont. Monomer a small molecule that is a subunit of a polymer Polymer macromolecule made of many monomers linked together Many organic molecules are polymers
3.2 Organic Molecules of Cells Four (4) categories of organic molecules in living organisms Carbohydrates Lipids Proteins Nucleic acids As your body digests food, these compounds are released and used to assemble the large macromolecules that make up your cells.
Carbohydrates Used as an energy source and structural component in living things. Occur as monosaccharides, disaccharides, or polysaccharides. Typically, the sugar glucose is a monomer for carbohydrate polymers.
Monosaccharides Only a single sugar molecule simple sugars Glucose C 6 H 12 O 6 Fructose and galactose are also examples
Monosaccharides: Ready Energy P. 33 GLUCOSE
Disaccharides Contains two monosaccharides bonded together. Maltose and sucrose are examples.
Polysaccharides Polymers of monosaccharieds Used for short-term energy storage, i.e. starch in plants and glycogen in animals. Cellulose is found in plant cell walls
Polysaccharide Energy Storage- Starch Plants P. 34
Polysaccharide Energy Storage Molecules-Glycogen Animals
Polysaccharides Structural Molecules- Cellulose Plants P. 34
3.2 Starch sources P. 32
Lipids Insoluble in water due to nonpolar hydrocarbon chains. Fats and oils are used for insulation and long-term energy storage. Made of two subunits: glycerol with a fatty acid tail
3.2 Fats Sources P. 32
Saturated vs. Unsaturated Fat Saturated fat has no double bonds between the carbon atoms; the carbon chain is saturated with all the hydrogens it can hold. Unsaturated fat has double bonds in the carbon chain, causing a bend in the chain. Saturated fat is solid at room temperature and unsaturated fat is liquid at room temperature.
Phospholipids and Steroids Phospholipids are found in cell membranes. Steroids are lipids with a different structure and include cholesterol, another part of the cell membrane
Proteins Important in the structure and function of cells. Protein functions include: - Support - Metabolism - Transport - Defense - Regulation - Motion
3.2 Protein Sources P. 32
Amino Acids Subunit of proteins There are 20 different amino acids Difference is found in the side chains
Amino Acids: Subunits of Proteins Amino acids- subunits of proteins. Amino acids have three elements to their structure. An amino ( NH 2 ) group A carboxyl ( COOH) group The R (Residual) group The R groups vary and make each amino acid unique.
Amino Acid Structure- R-group Examples P. 39
Peptide Bonds Amino acids are covalently bonded together, forming a peptide bond Peptide two or more amino acids covalently linked Polypeptide a chain of many amino acids joined by peptide bonds
Functional Groups P. 31
Protein Structure
Shape of Proteins- Primary sequence P. 40
Protein- Secondary Structure P. 40
P. 40 Pleated sheet (secondary) Teriary Structure- Helical + Pleated
More than one chain P. 40
Enzymes Protein that speeds a reaction in cells due to its particular shape Catalyst not consumed in the reaction Substrate bonds to the active site lock and key Lowers the amount of energy needed for reactions lower energy of activation
How Enzymes Work Lock and key hypothesis This is the simplest model to represent how an enzyme works. The substrate simply fits into the active site to form a reaction intermediate
How Enzymes Work
Factors Affecting Enzyme Activity Several factors affect the rate at which enzymatic reactions proceed Temperature ph enzyme concentration substrate concentration presence of inhibitors or activators.
Enzyme Inhibitors Some substances reduce or even stop the catalytic activity of enzymes in biochemical reactions. They block or distort the active site. These chemicals are called inhibitors, because they inhibit reaction.
Enzyme Activators Sometimes you need an enzyme to work faster and your body creates an activator. Other times you might eat something that acts as an activator. Activators make enzymes work harder and faster.
Nucleic Acids DNA and RNA are nucleic acids Made of subunits called nucleotides
Nucleic Acids The phosphate groups and sugars of nucleotides are linked to form the backbone of a DNA or RNA molecule. nitrogen-containing bases have specific complementary base pairing. In DNA or RNA, guanine + cytosine (G-C). In DNA, thymine + adenine (T-A). In RNA, uracil + adenine. (U-A) DNA - double helix of two spiral strands.
Nucleic Acid-Structure P. 41
Nucleic Acids (cont.) P. 41
RNA Uracil (U) instead of Thymine (T)
Nucleic Acids Complementary base pairing allows DNA to pass genetic information to RNA. The information in DNA is present in a triplet code where every three bases stands for one of the 20 amino acids. Sequencing of human DNA - called the Human Genome Project.
Relationship Between Proteins and Nucleic Acids Order of amino acids in a protein determines its shape and function. DNA contains the instructions for the sequence of amino acids in each protein. Errors or faults in the DNA can change the function of the encoded protein.