Unit #2 – Biomolecules: The Chemistry of Life

1. Unit #2 – Biomolecules: The Chemistry of Life Learning Focus 1.2 – The Structure & Function of Biomolecules

2. TEKS Objectives • (9)  The student is expected to: • (A)  compare the structures and functions of different types ofbiomolecules such as carbohydrates, lipids, proteins, and nucleic acids • (C) investigate and identify the effects of enzymes on food molecules.

3. Introduction • All life depends on chemistry to function. • During breathing and eating, the body uses oxygen other nutrients in chemical reactions to keep you alive. • In this chapter we will discuss the biological relationship between the elements within our world and the reactions within the body and other living things.

4. NutritionalLabels • Review the nutritional label. • How many grams of carbohydrates are found in this food? • What types of carbohydrates are listed? • Why do you think our bodies need carbohydrates? http://www.nestle.ca/NR/rdonlyres/EF764B3A-5216-46BA-95DC-B573C44EF266/0/BistroPestoGrChkn_NFT.gif

5. Types of Compounds • Organic compounds contain the element carbon and are found in living things. • Inorganic compounds do not contain carbon and are associated with non-living things. http://www.physicalgeography.net/fundamentals/images/compounds_molecules.jpg

6. Macromolecules & Biomolecules • Everything that is living is composed of molecules with carbon atoms. • Carbon has 4 valence electrons and can, therefore, forms many compounds with many elements. • Living cells are composed of HUGE molecules (macro-molecules) made of thousands of atoms. • The four biomolecules found in living things are carbohydrates, lipids, proteins, and nucleic acids.

7. Macromolecules are Huge! • One molecule of water (above). • One example of a macromolecule (lipid) to the right. • No Yellow? No Notes! http://www.matchrockets.com/images/h2omol.jpg http://www.chem.arizona.edu/faculty/mcgr/triazo.GIF

8. Carbohydrates • Carbohydrates are made up of carbon, hydrogen and oxygen atomsin a ratio of 2 H:1 O. • Carbs are used as a source of energy for living things. http://www.faqs.org/nutrition/images/nwaz_01_img0048.jpg http://newsletter.wsu.edu/eplay/user_pics/375x250_veggies.jpg

9. Simple carbohydrates are often called sugars (glucose, fructose (from fruits) and galactose (from milk)). Simple sugarsaremonosaccharides (one + sugar). Large molecules of carbsare called polysaccharides (many + simple sugars). Strings of monosaccharides make up a polysaccharide. Animals convert carbs and store the energy in the form of glycogen found in cells (often muscle cells). Plants store their carb energy in the form of starch and use cellulose for structure (think tough and fibrous like celery!). Carbohydrates Cont. http://biology.clc.uc.edu/graphics/bio104/glucose1.jpg

10. Lipids • Lipids (commonly known as fats, oils, and waxes) are a large macromolecule made from carbon, oxygen, and hydrogen atoms. • Hydrogen to oxygen ratio is (much greater than) >>>2:1. • Lipids are generally do not mix in water (hydrophobic). • They can be used tostore energy. • They are foundin cell membranes and help our skin keep from drying out. • Lipids are made up of glycerol and chains of fatty acids http://www.indiana.edu/~origins/images/lipid.gif

11. Types of Fats • Lipids can be saturated with only single bonds between atoms; solid at room temperature, and not healthy (butter, lard, manteca). • Unsaturated fats are considered the healthiestand are liquid at room temperature (olive oil, peanut oil, etc.) • Lipids can be monounsaturated (with one double bond between two atoms). • Polyunsaturated fats have more than one double bond. http://www.wholefoodsmarket.com/products/oil/images/oils300w.jpg

12. http://www.cramscience.ca/images/uploaded/uploadedLarge/1ff8e0a92c3974adacb557e5afa82bca.jpghttp://www.cramscience.ca/images/uploaded/uploadedLarge/1ff8e0a92c3974adacb557e5afa82bca.jpg

13. Proteins • Protein is our last macromolecule and contains the elements carbon, hydrogen, oxygen, and nitrogen. • They are made up of strings of amino acids. • There are more than 20 different amino acids found in nature. • Some proteins help to control cell processesand they are used to form muscles and bones. • They also help to fight disease and are used to transport substances.

14. An enzymeis a proteinthat acts as a biological catalyst. Enzymes work in cells. Catalysts speed up chemical reactions. The enzyme attaches to the substrate that it works with (the reactants). Now that the enzyme is connected to the substrates, the substrates will react and produce products. This is called the lock and key model because -specific enzymes will only work on specific substrates. Enzymes & The Lock & Key Model http://stezlab1.unl.edu/reu1999/dputn226/ChemHelp/RET_Web_Pages/Enzymes/lock_key1.gif

15. Chemical Reactions • A chemical reaction is a process that changes one set of chemicals into another set. • Reactants are the items that youbegin with. • Products are the itemsyouend up with. • AB + CD  AD + CB REACTANTS PRODUCTS http://eprentice.sdsu.edu/S03X2/guerra/burger2.gif • When you eat a burger, your body has to process and change that into parts the body can use.

17. Nucleic Acids • Nucleic acids are macromolecules containing hydrogen,oxygen, carbon, nitrogen, and phosphorus. • Nucleic acids make up our DNA and RNA! • Their function isgenetics; the DNA in your cells is responsible for giving you your unique characteristics. • DNA’s unique shape is called a double helix. • We will learn more about nucleic acids later in the semester when we get into DNA and genetics. http://www.scq.ubc.ca/wp-content/dna.gif

18. In Conclusion • To review… • In this unit we reviewed the structure of atoms. • We investigated four macromolecules needed for life (carbohydrates, lipids, nucleic acids, and proteins). • We learned that enzymes help to speed up reactions in body cells.