Chemistry of life

1. Chemistry of life Chapter 2

2. Lesson 1 Basic Chemistry

3. DO NOW • Define, in your own words: • Atom • Element • Proton • Neutron • Electron

4. Elements and Atoms • All matter is made up of substances called elements. • Only 92 naturally occurring elements • Body is composed of only a few elements • Carbon • Nitrogen • Oxygen • Hydrogen • Phosphorous • Calcium • Atoms – smallest unit of an element • Made up of: • Protons – + charge, nucleus of atom • Neutrons – 0 charge, nucleus of atom • Electrons – ( - ) charge, orbit around nucleus

5. Isotopes • Same element differs in the number of neutrons in the nucleus and weight. • Carbon has 2 common isotopes • Carbon-13 and Carbon-14

6. Radioactive Isotopes • As isotopes break down they release energy in the form of rays and subatomic particles • Carbon-14 is a common Radioactive isotope • Unstable and breaks down over time http://www.pbslearningmedia.org/resource/nvhe.sci.chemistry.decay/radioactive-decay-of-carbon-14/

7. Molecules and Compounds Molecule – 2 or more of the same atoms bonded together to form a chemical unit Compound – 2 or more different atoms bonded together to form a chemical unit. Types of Bonds: Ionic – created by an electrical attraction Covalent – sharing of electrons

8. Bonds

9. Bonds Chemical Bonds Double Bond – 2 pairs of electrons are shared Triple Bond – 3 pairs of electrons are shared • Polar Covalent – electrons spend more time with the more electronegative element • Non-polar Covalent – equally shared electrons

10. In class assignment • Elements in Living Things Coloring Handout

11. Homework • Study Questions pg 39 # 1-4

12. Lesson 2 Water, Acids and Bases

13. Do Now • Have your homework from last night out on your desk for me to check! • What is the difference between ionic and covalent bonds? • What elements make up the human body?

14. Organic vs Inorganic • Organic Molecules – contain carbon • Carbohydrates, proteins, lipids • Inorganic Molecules – do not contain carbon • Most important molecule is WATER

15. Water • Polarity and Hydrogen bonding gives water all of it’s unique and beneficial properties. • Solvent for polar molecules • Cohesive – water molecules stick together • Adhesive – water molecules stick to other surfaces • High Specific Heat Capacity/Heat of vaporization Video

16. Acids and Bases • Acids – substance that separates in water • Bases – takes up hydrogen ions or releases hydroxide ions • pH scale – ranges from 0-14, indicates the acidity and basicity of solutions pH scale Acids and bases

17. Acids and Bases • It’s important to maintain body fluid in a narrow pH range. (about 7.4) • Acidosis – pH value drops below 7.35 • Occurs when kidneys and lungs can’t keep your pH balanced • Alkalosis – pH value rises above 7.45 • Occurs when there is high levels of bicarbonate in your blood • Excessive loss of acid • Low carbon dioxide level • Buffers – help to keep pH in a normal range • they are chemicals or pairs of chemicals that take up excess hydrogen ions or hydroxide ions

18. Content Check • Depending on what you’ve eaten recently, the pH of your urine can vary from 5 to 8. • Which is more acidic – urine at pH 5 of pH 8

19. Electrolytes • A substance that releases ions when put into water • These ions can conduct an electrical current • Electrolyte balance is important for good health because it effects the functioning of vital organs.

20. Homework • Study Guide Questions pg 39 # 6-7

21. Lesson 3 Molecules of Life

22. Do Now • Macromolecules Handout • Hand in Properties of Water Lab Macromolecules

23. Molecules of Life

24. Molecules of Life • ^ Dehydration Synthesis • remove water, make bigger molecules • < Hydrolysis – add water, break down molecules

25. Carbohydratesquick, short-term cellular energy • Monosaccharide – one carbon ring. Ex: Glucose, Fructose • Dissaccharide – two carbon rings. Ex: sucrose • Polysaccharide – three or more carbon rings. Ex: starch, cellulose

26. Do NowSeptember 30, 2014 • Hand in your homework! • Take out your notes & be ready to work!

27. Carbohydrates • Made up of C, H, O in a 1:2:1 ratio • Glucose – used as an immediate source of energy • Maltose is 2 glucose molecules, found in alcoholic beverages • Sucrose – glucose & fructose together, this is table sugar • Lactose – glucose and galactose, this is found in milk

28. Polysaccharides • Means many sugars, LONG chains of sugar molecules • Starch – energy storage in plants • Glycogen – energy storage in animals • Cellulose – what cell walls are made up of • We cannot digest this, this helps to scrape the walls of our intestines

29. Common Polysaccharides

30. Lipidslong-term energy storage, part of membranes Saturated Fats - have only single covalent bonds, solid at room temperature. Ex: Butter (usually of animal origin) Unsaturated Fats – have double/triple bonds, liquid at room temperature. Ex: Oils (usually of plant origin)

31. Lipids Made of a glycerol molecule and a triglyceride, or three fatty acids. Can be emulsified – mixed with water, molecules position themselves around a droplet so that their nonpolar ends stick out and the droplet disperse in water Phospholipids – contain phosphate group, important for cell membranes Steroids – different structure than fats, back bone of 4 carbon rings, with differing side chains cholesterol is an example of a steroid

32. Proteinswide range of functions • Macromolecules made up of 20 different Amino Acids • Amino acids are arranged as follows • Central carbon atom • An amino group • An R Group

33. Structure of Proteins • Composed of amino acids • When two amino acids join, called a dipeptide • Polypeptide contains 3 or more amino acids • Primary Structure • Sequence of Amino acids in a polypeptide • Secondary Structure • Coiling or folding of the protein • Tertiary Structure • Hydrogen, ionic, covalent bonding all occur in polypeptides • Quaternary Structure • Protein that has more than 1 polypeptide, arrangement of individual polypeptides • When proteins are exposed to extreme heat and pH they denature, and this is irreversible

34. Protein Structure

35. Content Check • The sequence of amino acids found in a protein is that protein’s __________ structure a. primary b. secondary c. tertiary d. quaternary Why is it possible for humans to digest starch but not cellulose? a. starch is made of glucose molecules but cellulose isn’t b. Starch comes from plants but cellulose doesn’t c. The glucose units found in cellulose are linked differently than those in starch

36. Enzymes • Protein catalysts • Enable particular metabolic reaction to occur at the body’s normal temperature • Energy activation – energy needed to start a reaction • Substrates – reactants in an enzymatic reaction • Enzymes are very specific this is caused by the shape and chemical composition of it’s active site.

37. Enzyme Substrate Complex

38. Nucleic Acidscontain hereditary information • Two Classes: • RNA – ribonucleic acid, bases are AUGC (codes for proteins) • DNA – deoxyribonucleic acid, bases are ATGC (makes up genes)

39. Nucleic Acids

40. DNA v RNA

41. ATP • Adenosine plus 3 phosphate groups • PRIMARY ENERGY CARRIER IN CELLS • Cells require a constant supply  continually break down glucose • Some uses: • Synthesizing macromolecules • Muscle contraction • Conduction of nerve signals

42. In Class Assignment/Homework • Macromolecules Worksheet #2