Contain C Organic Molecules Can form 4 strong covalent bonds Ergo can form many complex, stable molecules Chemistry of life is complex, and requires complex molecules However, several kinds of molecules contain carbon but are not organic. CO 2, for example All organics are naturally produced by processes in living cells. The greater % of any organism consists of 4 elements: carbon, oxygen, hydrogen and nitrogen.
Carbohydrates Structure sugars The Four Main Types of Organic Molecules Consist of C, H, O General formula = (CH 2 0) n Often end in -ose 1.) Monosaccharides- simple sugars one ring; most are C 6 H 12 O 6 Isomers: same number and type of atoms, different structure» Glucose- store and release energy, mainly from C-H bonds; main transport sugar in vertebrates» Fructose» Galactose
The straight chains form rings in solution.
Monosaccharide isomers The difference between glucose and galactose is simply in the way two things (H and OH) are attached to one of the carbons in the ring.
Double sugars 2.)Disaccharides :eg sucrose, lactose, maltose 2 mono s bonded by dehydration synthesis Hydrolysis breaks them back into mono s Sucrose = glucose bonded to fructose» It is the main transport sugar in plants
Complex Carbohydrates Complex Carbs Polysaccharides-most are glucose polymers which form chains and branches Animal starch - glycogen Store energy in liver and muscles Plant starch- amylose Cellulose- structural function Cell walls Chitin-arthropod exoskeleton, fungus cell walls
Making and Breaking Organics All large organic polymers are made by joining smaller molecules called monomers in a chemical process called dehydration synthesis. They are broken back down by hydrolysis.
Lipids Lipids-functions include energy storage, forming structural parts, insulation, cushioning body organs, and being hormones Store 2 X as much energy/gram as carbs Insoluble in H 2 O Structure of most common lipids: Glycerol and fatty acids- Triglyceride (main type of lipid): 3 fatty acids and gycerol Fats and oils- Fats:Saturated- no double bonds between carbons, most H possible, animal products, solid at room temp. Oils: Unsaturated- double bonds, liquid (oils), plant products Lipid with a structural function example: Phospholipids in ALL cell membranes (NOT cell walls) Omega 3 oils are unsaturated and very healthy Hydrogenated trans fatty acids are bad Waxes
Introduction Lipids are an exception among macromolecules because they do not have polymers. The unifying feature of lipids is that they all have little or no affinity for water. This is because their structures are dominated by nonpolar covalent bonds. Lipids are highly diverse in form and function. Copyright 2002 Pearson Education, Inc., publishing as Benjamin Cummings
1. Fats store large amounts of energy Although fats are not strictly polymers, they are large molecules assembled from smaller molecules by dehydration reactions. A fat is constructed from two kinds of smaller molecules, glycerol and fatty acids. You should be able to recognize a sketch of a fatty acid and a glycerol. Copyright 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Glycerol consists of a three carbon skeleton with a hydroxyl group attached to each. A fatty acid consists of a carboxyl group attached to a long carbon skeleton, often 16 to 18 carbons long. Fig. 5.10a Copyright 2002 Pearson Education, Inc., publishing as Benjamin Cummings
The many nonpolar C-H bonds in the long hydrocarbon skeleton make fats hydrophobic. In a fat, three fatty acids are joined to glycerol creating a triglyceride. Fig. 5.10b Copyright 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Saturated vs. Unsaturated Fats
Lipid hormones made from cholesterol
Cholesterol is a sterol. Not a glyceride type, but a lipid still.
Cholesterol is needed for: Your cells use it to make the sterol hormones testosterone and estrogen as well as vitamin D (with sunshine s help in your skin cells). Cholesterol is in all animal cell membranes, but not plant or any other cell membranes, which is why plants have no cholesterol.watch
Proteins - Amino Acid Polymers
Peptide bond formation Amino acids are joined by a type of covalent bond called a peptide bond during dehydration synthesis. Bonding is always between the carboxyl group of one and the amine group of the other.
Proteins show great variety There are 20 different kinds of amino acids An infinite number of different proteins is possible by combining different amino acids in different sequences. In actuality, we find several thousand kinds of proteins in living things.
Protein Functions Structural proteins- eg. Keratin, collagen, silk Hormones: Insulin, Human Growth Hormone Enzymes- catalysts; ususally have an -ase ending. Sucrase. Transport proteins: in cell membrane and in circulatory systems. Hemoglobin, for example. Defense function: Antibodies - made by white blood cells in the immune system Denaturation - when bonds break, often by heat, the protein loses its natural shape, and therefore its function
Primary Structure The order of amino acids determines what the shape of every protein will ultimately be. Identical chains will always fold up the same way.
Even small changes in primary structure can be deadly
Secondary structure Linus Pauling won a Nobel Prize for discovering the alpha helical shape of many proteins. 2 0 structure is caused by hydrogen bonding between amino acids in the chain, producing regular, repeated patterns.
These irregular foldings are due to many different types of bonds between R groups. The H bonds which determine secondary structure are not between R groups. Tertiary Structure
Quaternary structure: multiple chains combine to make 1 protein
Two overall shapes of proteins When a protein has taken its final shape, it will be classified as one of two possible: Fibrous (string-like): Collagen, silk Globular (roundish): Hemoglobin, insulin, all enzymes Let s look at some animations Secondary tertiary quaternary
Which of the following is not normally a function of proteins in healthy cells? A. functioning as catalysts B. long-term energy storage C. a component of cell membranes D. Transport of particles
Athletes are often concerned with the question of how much protein they need in their diets because of the requirement of growing muscles for protein. Just as muscles need the basic building block of protein, protein itself has basic building blocks. Which of the following are the basic building blocks of protein? a. Nitrates b. Amino acids c. Monosaccharides d. Nucleotides
Based on the students results, at what ph does catalase work best: 1,4,7, or 10?