BIOCHEMISTRY p ½ cup of CHEX MIX

BIOCHEMISTRY

p ½ cup of CHEX MIX contains 13 g of carbs = 4% daily value…. How much more can you have the rest of the day? ? ? _4_ = 13 100 X X= 325 g

p These spinach imposters contain less than 2 percent of “spinach powder” seasoning. Yum! And the wraps’ green color? Courtesy of food dyes yellow #5 and blue #1. p When was the last time you saw a flowering field of disodium phosphate? Or how about a fresh crop of maltodextrin? Didn’t think so. These cheese puffs consist largely of corn, but they’ve been processed to the point that no 20 th-century farmer would ever recognize them as food.

p In the short run, food choices make a difference. For example, a diet that’s low in iron—typical among teenage girls—may result in anemia, which causes paleness and a tired feeling. A teenage athlete who cuts back on calories to trim down may not have enough energy for peak performance. And eating more calories than you use often shows up as extra pounds of body fat. p Ask students what snacks they often buy and if they look at the nutrition facts label. For those students that do look at the label, what do they look for when choosing a snack? p Remember the largest amount of ingredients found in your product are listed on the label first and the smaller % amounts in the bottom

Carbon Can form large and complex structures p Organic Chemistry - study of carbon componds p

Organic vs. Inorganic Compounds p Organic Compounds – Compounds that contain carbons. n p Lipids, proteins, nucleic acids, carbohydrates Inorganic Compounds – Compounds that do NOT contain carbon. n Salts, water, oxygen

Macromolecules p Macromolecules – “Giant molecules” made from smaller molecules n n Formed by a process known as polymerization, in which large compounds are built by joining smaller ones together. The smaller units, or monomers, join together to form polymers.

Organic Compounds p Four groups found in living things are: 1. Carbohydrates 2. Lipids 3. Nucleic Acids 4. Proteins

Carbohydrates (carbo =carbon hydrate = H 20) p Compounds made up of carbon, hydrogen, and oxygen atoms n Ratio of 1 : 2 : 1.

Uses of Carbohydrates p Living things use carbohydrates as: 1. Main source of energy (starches and sugars) 2. Plants and some animals also use carbohydrates for structural purposes

Uses of Carbohydrates p Animals n Store excess sugar in the form of glycogen p p Plants n n p Located/made in liver and muscles Store excess sugar in the form of starch for energy Use tough, flexible cellulose fibers to give them their strength and rigidity Both n Glucose is main energy source for cells

Classification of Sugars p Monosaccharides – Single (simple) sugar molecules n p Examples: Glucose, Galactose, Fructose Disaccharides – Double sugar molecules n Examples: Glucose + Fructose = Sucrose p Glucose + Galactose = Lactose p Glucose + Glucose = Maltose p p Polysaccharides – More than two monosaccharide molecules n Examples: Starch, Cellulose, Chitin, Glycogen

Classification of Sugars

Lipids p Common categories of lipids are 1. 2. 3. p Functions: 1. 2. 3. p Fats Oils Waxes Can be used to store energy Some lipids are important parts of biological membranes and waterproof coverings Can serve as chemical messengers (steroids only) Generally not soluble in water

Structure of Lipids Made mostly from carbon and hydrogen and oxygen atoms p Usually has relatively small amounts of oxygen p Glycerol molecule + 3 fatty acids (Triglycerides) p Steroid (4 rings)

Saturated and Unsaturated Lipids p Saturated - If each carbon atom in a lipid's fatty acid chains is joined to another carbon atom by a single bond. n n n “Saturated” means it has the maximum possible number of hydrogen atoms Solid at room temperature Examples – Cholesterol, butter, chocolate

Saturated and Unsaturated Lipids p Unsaturated- If there is at least one carbon-carbon double bond in a fatty acid. n n Liquid at room temperature Examples - Corn oil, sesame oil, canola oil, and peanut oil

Proteins - Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen. p Made up of chains of amino acids folded into complex structures. p n Amino Acids - Compounds with an amino group (−NH 2) on one end a carboxyl group (−COOH) on the other end.

Amino Acids There are more than 20 different amino acids. p Any amino acid may be joined to any other amino acid by bonding an amino group to a carboxyl group by dehydration synthesis. p *When the length of a polypeptide (chain of aa) is more than ~100 aa the molecule is called a protein*

Amino Acids There are more than 20 different amino acids. p What distinguishes one amino acid from another is the R-group (functional group) section of the molecule. p

Functions of Proteins p Each protein has a specific role. 1. Some proteins control the rate of reactions and regulate cell processes. u 2. Some are used to form bones and muscles and tissues. u 3. Enzymes Structurally = collagen and keratin Others transport substances into or out of cells or help to fight disease. u u Antibodies Transport channels in the cell membrane

Nucleic Acids p p Nucleic acids - Macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. Made up of repeating units called nucleotides n Each nucleotide contains: 1. 2. 3. 5 -Carbon Sugar Phosphate Group Nitrogenous Base

Nucleic Acids p Function: n n p Store genetic information Transmit genetic information Two Kinds of Nucleic Acids: 1. Ribonucleic acid (RNA) p p 2. Contains the sugar ribose Single stranded Deoxyribonucleic acid (DNA) p p Contains the sugar deoxyribose Double stranded

Dehydration Synthesis p p Dehydration synthesis – A chemical reaction that builds up molecules by losing water molecules. Used to put together monomers to build polymers. n The “dehydration” part is the removal of water n The “synthesis” part is the joining of the two smaller compounds to create one larger one TRICK: There will always be one less water produced than the number of monomers joining together. http: //www. youtube. com/watch? v=Uy. Dnn. D 3 f. Ma. U

Hydrolysis p Hydrolysis – The rupture of chemical bonds by the addition of water. Used to break down polymers into their monomers. p http: //www. goldiesroom. org/Shockwave_Pages/Make%20 and%20 Brake%20 Em. htm p

Chemical Reactions p Chemical Reaction - A process that changes one set of chemicals into another set of chemicals. n Always involve the breaking of bonds in reactants and the formation of new bonds in products.

Chemical Reactions and Water Molecules cannot react chemically unless they are in solution, so virtually all chemical reactions in the body depend upon water’s solvent properties. p Most abundant inorganic compound in the body (accounts for 2/3 of body weight). p

Chemical Reactions Reactants - The elements or compounds that enter into a chemical reaction. p Products - The elements or compounds produced by a chemical reaction. p Na + Cl Na. Cl Reactants Products

Energy in Reactions Because chemical reactions involve breaking and forming bonds, they involve changes in energy. p Will the chemical reaction occur? p n Chemical reactions that release energy often occur spontaneously. p n Energy is released in the form of heat, light, and sound. Chemical reactions that absorb energy will not occur without a source of energy. p Every organism must have a source of energy to carry out necessary chemical reactions.

Organisms and Energy p Plants n p Get their energy by trapping and storing the energy from sunlight in energy-rich compounds. Animals n n Get their energy when they consume plants or other animals. Release the energy needed to grow tall, to breathe, or to think through the chemical reactions that occur when humans metabolize, or break down, digested food.

Activation Energy p Activation Energy - The energy that is needed to get a reaction started. n n The peak of each graph represents the energy needed for the reaction to go forward. The difference between this required energy and the energy of the reactants is the activation energy.

Catalysts p Some chemical reactions that make life possible are too slow or have activation energies that are too high to make them practical for living tissue and cells. p Catalyst - A substance that speeds up the rate of a chemical reaction by lowering a reaction’s activation energy.

Enzymes p Enzymes - Proteins that act as biological catalysts. n n n Speed up chemical reactions that take place in cells. (by lowering activation energy) Very specific, generally catalyzing only one chemical reaction. Part of an enzyme's name is usually derived from the reaction it catalyzes.

How Do Enzymes Work? p p Substrates - The reactants of enzyme-catalyzed reactions. The Enzyme-Substrate Complex n n Enzymes provide a site where reactants can be brought together to react. This site reduces the energy needed for reaction. Each protein has a specific, complex shape. Active Site – The site on the enzyme where substrates bind. p The active site and the substrates have complementary shapes, which is often compared to a lock and key model.

Enzyme Substrate Complex Active site

Regulation of Enzyme Activity p Enzymes can be affected by any variable that influences a chemical reaction such as: 1. 2. 3. p. H Temperature Cells contain proteins that help to turn key enzymes “on” or “off”

Animations to help explain: p http: //www. lpscience. fatcow. com/jwanam aker/animations/Enzyme%20 activity. html