1. Chapter 2 Chemistry of Life

2. I. Atoms and Bonding A) Elements - subst cannot be broken down into another subst 1. 25 needed by orgs 1. 25 needed by orgs 2. 4 elements make up 96% of orgs 2. 4 elements make up 96% of orgs a) Carbon (C) b) Nitrogen (N) c) Oxygen (O) d) Hydrogen (H)

3. 3. trace elements – important for cell processes! 3. trace elements – important for cell processes! a) plants absorb thru roots b) animals get thru food c) Ex: Mg, Ca, Fe, etc B) Chemical bonding – attraction that holds atoms tog 1. Ionic bond- between + and – charged ions

4. a) ions - atoms that have gained /lost electrons (e-). Do this to get 8 e- in valence (outer energy) level of atom b) metals and nonmetals ionic bond b) metals and nonmetals ionic bond c) Ex: Al +3 + O -2 → Al 2 O 3 c) Ex: Al +3 + O -2 → Al 2 O 3

5. 2. covalent bond – atoms share electrons to get 8 in outer level 2. covalent bond – atoms share electrons to get 8 in outer level a) nonmetals and nonmetals (organic) a) nonmetals and nonmetals (organic) b) Ex: CH 4 b) Ex: CH 4 Each H atom has 1 e- and wants 2 to be stable. Carbon has 4 e- and wants 8. Move in close and share e-

6. C) Chemical Rxns - bonds bt atoms C) Chemical Rxns - bonds bt atoms break and recombine to make new subst(s) break and recombine to make new subst(s) 1. Ex

7. 2. Must be balanced to agree w/ Law of conservation of mass (Mass cannot be created or destroyed in a closed system) 2. Must be balanced to agree w/ Law of conservation of mass (Mass cannot be created or destroyed in a closed system) II. Water - H 2 O necessary for almost all life forms! almost all life forms! A) Water - is a polar molecule, has a A) Water - is a polar molecule, has a positively charged end and a positively charged end and a negatively charged end negatively charged end

8. 1. attracts other H 2 O molecules & ions 2. hydrogen bond - weak attraction bt + H end of molecule and - O end of molecule. Keeps from evap at low temps bt + H end of molecule and - O end of molecule. Keeps from evap at low temps

9. 3. dissolves many ionic compounds to release ions needed for cell processes 3. dissolves many ionic compounds to release ions needed for cell processes

10. III. Structure of organic compounds- Carbon based A) Carbon - "element of life" A) Carbon - "element of life" 1. Has 4 valence e- - forms 4 bonds 1. Has 4 valence e- - forms 4 bonds 2. Can form double, triple bonds 2. Can form double, triple bonds B) polymers - long chain of many B) polymers - long chain of many smaller molecules (monomers) bonded tog smaller molecules (monomers) bonded tog 1) Ex: sugars& carbs, proteins, etc etc

11. 2. formed through condensation - when H of 1 molecule bonds w/ OH of another molecule, H 2 O is formed and released Monomer

12. 3. broken through hydrolysis - 3. broken through hydrolysis - when H 2 O is used to break polymers. H+ and OH- ions from H 2 O move into molecule and break it apart when H 2 O is used to break polymers. H+ and OH- ions from H 2 O move into molecule and break it apart

13. IV. Types of organic compounds A) Carbohydrates - ("sugars"). A) Carbohydrates - ("sugars"). 1. made of C, H, & O (Ex: C6H12O6) 1. made of C, H, & O (Ex: C6H12O6) 2. monosaccharides – 2. monosaccharides – a) simple" sugars a) simple" sugars b) Glucose & Fructose ( isomers) b) Glucose & Fructose ( isomers) 3. disaccharides - a) 2 sugars form thru condensation a) 2 sugars form thru condensation b) C 12 H 22 O 11 - Sucrose, made b) C 12 H 22 O 11 - Sucrose, made when fructose and glucose combine.

15. 4. polysaccharides - polymers of 4. polysaccharides - polymers ofmonosaccharides a) starch - plant food storage, a) starch - plant food storage, also in seeds b) glycogen - more complex, b) glycogen - more complex, animals store in liver for energy c) cellulose - forms cell wall of c) cellulose - forms cell wall of plant cells & support stems

17. B) Lipids - (fats & oils) - needed by all B) Lipids - (fats & oils) - needed by all Orgs Orgs 1. large ratio of H:C, few O, Ex:(C 57 H 110 O 6 ) 2. nonpolar - insoluble in H 2 O 3. Role in cells a) insulation a) insulation b) make up cell membrane b) make up cell membrane c) protection c) protection d) energy storage d) energy storage

18. 4. Fatty acids - organic acids attached to C chains a) saturated - all single bonds b) unsaturated - dble/triple bonds, could break, hold more H Double Bond

19. C) Proteins - Essential to life!!!!!!!!!!! C) Proteins - Essential to life!!!!!!!!!!! 1. structure- COHN & S (often) 1. structure- COHN & S (often) a) polymers of amino acids (aa) a) polymers of amino acids (aa) b) 20 common aa's b) 20 common aa's c) combine to make 1000s of c) combine to make 1000s ofproteins d) form thru condensation, forms d) form thru condensation, forms peptide bond e) order of aa's det type of protein e) order of aa's det type of protein f) Characterized by an amine group (NH 2) group f) Characterized by an amine group (NH 2) group

20. 1 single amino acid Peptide bond Polymer of amino acids = PROTEIN

21. 2. Function a) make up tissues, organs, a) make up tissues, organs, pigments, etc. pigments, etc. b) immune system, carry O 2 in b) immune system, carry O 2 in blood blood c) regulate chem. processes in cell c) regulate chem. processes in cell

22. 3. Enzymes - proteins that alter the rate of rxns in orgs (catalysts!) a) ex: neurotransmitters, digestive chemicals, hormones digestive chemicals, hormones b) dis/assemble molecules b) dis/assemble molecules 1. active site of enzyme 1. active site of enzyme designed to lock into substrate (molecule that is being acted upon) 2. enzyme changes shape, stretches /contracts substrate 2. enzyme changes shape, stretches /contracts substrate 3. releases, repeats 3. releases, repeats

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24. D) Nucleic acids - make up DNA (Deoxyribonucleic acid) & RNA - (Deoxyribonucleic acid) & RNA - 1. DNA / RNA – macromolecules(huge) 2. polymers of nucleotides - C,H,O,N,P a) nitrogen base b) sugar c) phosphate group d) nucleotides held tog by phosphodiester bond

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