1. Do Now: In your notebooks, answer: What nutrients do we need to survive? List as many as you can think of, and why we need them.

2. Definitions Nutrient - Any substance taken up by living things that promotes growth. Vitamin - Substance required in small amounts, essential for life but the organism cannot make itself Mineral – An inorganic solid

3. I. Major elements A. What makes up living matter (and what we consume to survive): 1. Carbon18.5% 2. Oxygen65.0% 3. Hydrogen 9.5% 4. Nitrogen 3.3% Total96.3%

4. II. Most of the 3.7% A. Phosphorus B. Sulfur C. Calcium D. Potassium III. Trace elements A. Those required by an organism in only minute quantities. 1. Iron 2. Iodine 3. Zinc & Copper 4. Manganese

5. Iodine Iodine is necessary for the synthesis of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). When levels of thyroid hormones fall, thyrotropin- releasing hormone is produced by the hypothalamus. TRH then prompts the pituitary gland to make thyroid stimulating hormone (TSH), which stimulates the thyroid gland’s production of T4 and T3. It also causes the thyroid gland to grow in size by increasing cell division.

6. IV. Elements vs. Compounds A. Element – substance that cannot be broken down to other substances by chemical reactions. B. Compound – substance made of two or more different elements combined in a fixed ratio 1. Ex: NaCl, H 2 O, C 6 H 12 O 6

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8. So how do these elements combine to form compounds?

9. V. Reactivity! A. You can tell how reactive an element is, and what it will react with, based on its atomic structure. Nucleus protons (+) neutrons Orbital electron (-)

10. VI. How to identify an element A. Name 1. Atomic Symbol (X) a) Usually the first or first two letters of the element’s name b) Some exceptions: Iron (Fe), Potassium (K) B. Atomic Number (Z) 1. Equals the number of protons in the nucleus 2. Unique to each element! C. Atomic Mass (A) 1. Average number of protons and neutrons in the nucleus ZAXZAX

11. Example Problems Lithium: 3 7 Li #protons #electrons #neutrons Sulfur: #protons 32 S #electrons 16 #neutrons *Periodic table

12. VII. Valence Electrons A. e - in the outermost orbital that can form bonds B. Electron orbitals 1. The octet rule a) 1 st orbital fills up at 2 electrons b) Other orbitals fill up at 8 C. Periodic Table activity

13. C. Bonds they can form 1. Ionic Bond a) Chemical bond formed when 1/more electrons are transferred from one atom to another b) Form ions

14. 2. Covalent Bond a) chemical bond formed when electrons are shared between atoms b) Co - valen -

15. VIII. Chemical Reactions A. Reactants & Products 1. CO 2 + H 2 O  H 2 CO 3 B. Energy is released or absorbed when bonds are formed or broken 1. Spontaneous reactions release energy 2. Other rxns need a source of energy to happen

16. C. Getting a rxn started 1. Requires activation energy 2. Every rxn has an activation energy whether it releases or absorbs energy D.Enzymes catalyze rxns by LOWERING the activation energy

17. E. The enzyme-substrate complex

18. Molecular models of the 3 states of matter