1. BIOLOGY NOVEMBER 2015 Biochemistry

2. DESCRIBE THE FUNDAMENTAL CHEMISTRY OF LIVING CELLS Standard 2, Objective 1

3. Components of Matter: What are you made of? Living things are made of matter  Anything that occupies space and has mass The atom is the basic unit of matter  Protons (+) and neutrons (0) are in the nucleus and electrons (-) orbit the nucleus

4. Components of Matter: What are you made of? Chemical substance  Material that has a definite chemical composition Element  Pure substance that cannot be broken down  About 117 elements currently known  Most elements from 1-92 are naturally occurring. Others are man-made.  Number of protons identify the element  1 proton = hydrogen, 11 protons = sodium, etc.

5. Components of Matter: What are you made of? Chemical compound  Atoms of two or more elements bonded together  Ionic bond  Electrons transferred between atoms  Covalent bond  Electrons shared between atoms

6. OBJECTIVE: IDENTIFY THE FUNCTION OF THE FOUR MAJOR MACROMOLECULES (I.E. CARBOHYDRATES, PROTEINS, LIPIDS, AND NUCLEIC ACIDS) Macromolecules: Are You What You Eat?

7. Organic compounds  Compounds that contain carbon  Make up organisms and carry out life processes  Nearly 10 million compounds known Macromolecules: Large molecules

8. Macromolecules: Are You What You Eat? Carbohydrates  Sugars and starches  Provide energy  Contain only carbon, oxygen, and hydrogen  Most common of the four macromolecules

9. Macromolecules: Are You What You Eat? Types of carbohydrates  Simple – 1-2 sugars  Quick energy  Complex – many sugars  Long-term energy

10. Macromolecules: Are You What You Eat? Lipids  Fats, oils, waxes  Long-term energy source  Contain carbon, hydrogen, and oxygen  Not soluble in water

11. Macromolecules: Are You What You Eat? Types of lipids  Triglycerides (fats)  Main form of stored energy in animals  Phospholipids  Cell membranes  Steroids  Cholesterol, hormones

12. Macromolecules: Are You What You Eat? Proteins  Made of amino acids  Contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur  Types of proteins:  Enzymes  Antibodies  Muscle fibers  Protein sources:  Meat, poultry, fish, legumes

13. Macromolecules: Are You What You Eat? Functions of proteins  Provide scaffolding that maintains shape of cells  Enzymes – speed up chemical reactions in cells  Antibodies – target invaders for destruction  Carry messages or materials  Hemoglobin in blood

14. Macromolecules: Are You What You Eat? Nucleic acids  Carry genetic information  Contain carbon, hydrogen, oxygen, nitrogen, and phosphorus  Made up of smaller units called nucleotides  DNA and RNA

15. OBJECTIVE: EXPLAIN HOW THE PROPERTIES OF WATER (E.G. COHESION, ADHESION, HEAT CAPACITY, SOLVENT PROPERTIES) CONTRIBUTE TO MAINTENANCE OF CELLS AND LIVING ORGANISMS. Water

16. The human body is 50- 75% water. About 75% of the earth’s surface area is covered with water.

17. Water Chemical Properties of Water  One oxygen atom and two hydrogen atoms H2OH2O  The two hydrogens have a slight positive charge  The oxygen has a slight negative charge  The resulting molecule is polar (+ on one side and – on the other)

18. Water Chemical Properties (continued)  Positive (hydrogen) part of one water molecule is attracted to the negative (oxygen) part of another water molecule.  Hydrogen bond  Weak attraction  One hydrogen bond isn’t strong, but the attraction is greater when many molecules are involved

19. Water Properties of Water  Cohesion  Tendency of water molecules to stick together  Water molecules stick together and form a droplet  Surface tension  Water molecules form an invisible layer which can hold weight  Due to cohesion

20. Water Adhesion  Water molecules stick to other surfaces  Capillary action – water taken up by roots

21. Water Density  Density is mass divided by volume  Water’s density is 1 g / ml  Solid water (ice) has a lower density than liquid water  Due to hydrogen bonding  In the solid state the water molecules are spaced farther apart

22. Water Universal solvent  Solute – that which is dissolved  Solvent – that which does the dissolving  Many chemicals are soluble in water because of its polar nature

23. Water Heat Capacity  High heat capacity  It takes a lot of energy to raise or lower the temperature of water

24. Water Solutions can be acidic, neutral, or basic pH Scale  Ranges from 0-14  pH = -log[H + ]  The lower the pH, the higher the H + concentration  Each number is a factor of 10  pH of 3 has 10 times the H + concentration of pH of 4

25. Water Acids  pH < 7  Sour taste  Release hydrogen ions  Tend to eat metals  Turn litmus paper red

26. Water Bases  Bitter  Tend to be slippery  Give off OH - ions  Turn litmus paper blue

27. OBJECTIVE: EXPLAIN THE ROLE OF ENZYMES IN CELLULAR CHEMISTRY Enzymes & Chemical Reactions

28. Rates of Chemical Reactions Many reactions must take place in order for the body to carry out basic functions These reactions must happen at the appropriate speed

29. Factors That Help Speed Up Chemical Reactions Higher concentrations of reactants  The more reactants there are, the more likely they are to collide and react Higher temperatures  Molecules have more energy to move, collide, and react Enzymes  Act as catalysts  Bring reactants together to collide and react

30. Enzymes and Biochemical Reactions Catalyst  Chemical that speeds up reactions Enzyme  Protein that acts as a catalyst Enzymes are not used up in reactions  Can be used over and over Enzymes are highly specific  Most catalyze only one or a few reactions  “Lock and Key” hypothesis Enzyme animations herehere

31. How Enzymes Work Enzymes lower the activation energy of chemical reactions  Activation energy: Energy needed for a reaction to take place How is activation energy lowered?  Reactants brought together  Reactants oriented properly  Allow reactions to proceed through different pathways that require less energy

32. What can affect enzyme function? pH  Some enzymes work better in acidic conditions, some in basic conditions, and others in a neutral environment Temperature  Cold temperatures can deactivate enzymes  Hot temperatures can denature enzymes  Shape changed permanently

33. Why are enzymes important? Enzymes involved in most chemical reactions in the body About 4,000 reactions Needed for reactions that:  Regulate cells  Allow for movement  Transport materials  Move things in/out of cells  Digest food Enzymes end in –ase  Amylase, lactase, etc.