1. Unit 2 - Biochemistry

2. -The atom is the smallest part of an element that can exist alone and maintains a set of specific properties
-PARTS of the ATOM are called subatomic particles

3. Subatomic particles Electrons: Neutrons: Protons:
Negatively (-) charged
Found in orbitals, electron cloud
Symbol = e-
Neutrons:
Neutral particles
Found in nucleus
Symbol = n
Protons:
Positively (+) charged
Found in nucleus
Symbol = p+

4. How to Read the Periodic Table…
Atomic Number
Equal to # of p+ and e- in an element
Element Symbol
Atomic Mass
The number of p+ plus n in the nucleus. The average mass of all elements and their isotopes. (isotopes= forms of the element with different numbers of neutrons)

5. Energy Levels- How many “rings” of electrons each element has
Energy Levels- How many “rings” of electrons each element has. 1st Energy Level can hold up to2 e- 2nd Energy Level can hold up to 8 e- 3rd Energy Level can hold up to 8 e- Valence Electrons- Electrons on the outermost energy level. These are involved in bonding.

6. 8 protons
8 electrons 16
-8 protons
8 neutrons
8 p+
8 n

7. Compounds Ex: H2O or CO2 or NaCl
Compound = substance formed by chemical combination of two or more elements in definite proportions
 Ex: H2O or CO2 or NaCl
Have properties that are different than the elements that make it up
Ex: NaCl = Na + Cl
Na is a metal
Cl is a poisonous gas
NaCl = table salt

8. BRAIN CHECK! Compound or Element: 1. NaCl 6. Fe 2. H2O 7. N
3. H  8. CO2
4. H2  9. Ar

9. Chemical bonds What is a chemical bond
Chemical bonds What is a chemical bond? A force that hold atoms together. The force is electrical. + and - attract. Bonds form because of valence electrons (e- in the outer shell).

10. Chemical bonding Atoms with full valence (outer) shells
Do not react with other atoms
Atoms with incomplete valence (outer) shells
React with other atoms

11. Ionic, Covalent, Hydrogen, and Polar Covalent
TYPES OF BONDS
Ionic, Covalent, Hydrogen, and Polar Covalent

12. Ionic bonds Very strong Opposite charges attract
One atom “grabs” or transfers electrons to another atom “gluing” or bonding them together
Metal + Nonmetal
Na Cl = table salt or NaCl

13. Ionic bonding
Think of it as “stealing” an electron
If an atom ends up with more protons than electrons (because it gives away an electron) it becomes positive.
If an atom ends up with more electrons, it becomes negative.

14. Notice how “losing” and electron makes an atom more positive (CATION)
“gaining” an electron makes an atom more negative (ANION)

15. Covalent bonding “sharing” electrons
Neither atom donates an electron, but they share it forming a bond
Weaker bond
Examples: Water, sugar, ammonia, octane (part of gasoline)

16. Hydrogen Bonding
A weak bond formed when hydrogen (being slightly positive) bonds with an electronegative atom in another molecule.
Hydrogen bonds are easily broken
Play an important role in living systems

17. Van Der Waals Forces* just a fun fact!!!
Van Der Waals Forces – intermolecular forces of attraction between atoms/molecules
Not as strong as covalent or ionic bonds
When mlc are close together, a slight attraction can occur.

19. The wild world of water

20. Water properties
 Polarity = there is an uneven distribution of electron between the oxygen and hydrogen atoms
This is called a polar covalent bond
 The "shared" electrons spend more time around the oxygen (making it partially negative) than the hydrogens (making them partially positive)

21. Water properties
Hydrogen Bonds (partial positive and negative charges attract) a result of polar covalent bonds
Polar Covalent Bonds
 Cohesion = attraction between molecules of the same substance
Adhesion = attraction between molecules and other substances due to polar attractions

22. pH and Buffers

23. A solvent is a substance in which another substance is dissolved.
Water and Solutions
A solvent is a substance in which another substance is dissolved.
A solute is the substance that is dissolved in the solvent.

24. Water is polar!
It likes to mix with other polar molecules (like NaCl – salt)
It won’t mix with other non-polar molecules like lipids

25. Water and Solutions
Acids and Bases
Substances that release hydrogen ions (H+) when dissolved in water are called acids.
Substances that release hydroxide ions (OH–) when dissolved in water are called bases.

26. The measure of concentration of H+ in a solution is called pH.
The pH scale is Logarithmic, meaning that each number is 10x more potent (a pH of 9 is 10x more basic than a pH of 8)

27. Acids
Taste sour
Release H+ ions in water
Less than 7 on the pH scale

28. Bases (alkaline) Feel slippery Release OH- ions
Have a pH higher than 7

30. Buffers are mixtures that can react with acids or bases to keep the pH within a particular range.

31. Biological Molecules

32. Carbon = Organic
Carbon can share one electron in a single bond, two electrons in a double bond.
When these bonds are broken ENERGY IS RELEASED!!!

33. Carbon – Carbon Bond Breaking this bond releases energy!
The more C-C bonds are in what you ingest, the MORE ENERGY you get.

34. ORGANIC COMPOUNDS
LIPIDS
PROTEINS
NUCLEIC ACIDS
CARBOHYDRATES

35. Molecules Groups of atoms bonded together
Macromolecule (macro = big) – a large molecule formed by bonding smaller molecules together
Also called Polymer (poly = many and meros = part)

36. Biological Polymers
Carbohydrates
Lipids
Proteins
Nucleic Acids

37. CARBOHYDRATES

38. Carbohydrates (Carbs)
Made of C, H, and O in a ratio of 1:2:1
Monomer = monosaccharide
Polymer = disaccharide or polysaccharide
Carbs are sugars!
USES
Glycogen - animal starch stored in liver & muscles
Cellulose - indigestible in humans - forms cell walls
Starches - used as energy storage in plants

39. Carbohydrates Monomer- Monosaccharides Glucose Polymer- Dissacharides
Sucrose, Lactose, Fructose
Polymer- Polysaccharides
Gylcogen

41. SHORT TERM ENERGY BOOST!
MANY C-C BONDS THAT STORE ENERGY!!! WOOOO!

43. LIPIDS

44. Lipids (FAT! YUM) Made of C, H and O Monomer = fatty acid
Polymer = triglyceride
Hydrophobic = won’t dissolve in
Water
USES
Oils, Fats, Waxes
Stores LONG TERM energy

45. Saturated and Unsaturated
Each tail is a chain of C bonded to H and other C by SINGLE or DOUBLE bonds
Lipids with tails that have only single bonds are Saturated b/c no more H will fit in the chain – it’s full!
Unsaturated has one double bond and can fit more H
Animal fats are solid at room temp
Plant fats are liquid at room temp
Animal Fats
Plant Fats

47. Phospholipid
Makes up cell membrane
Serves as a barrier

48. Steroids Aren’t just drugs to get swol – they’re important for us all!
Includes cholesterol and some hormones

49. PROTEIN

50. Proteins Made up of elements C,H,O,N and S
Monomer = amino acid (20 kinds)
Polymer = polypeptide/ protein
USES
Transport substances in and between cells
growth and development
immune system
Enzymes
hormones

51. FORM follows FUNCTION

53. Protein Folding
The FORM of a protein determines the FUNCTION

54. NUCLEIC ACIDS

55. Nucleic Acids Made of C,H,O,N,P Monomer = nucleotide
Polymer = DNA or RNA
Complex macromolecules that store or transmit genetic information
Nucleotides and made of 3 molecules:
Phosphate
Nitrogenous base
Ribose sugar

57. Why is this an inaccurate picture of nutrition?

58. Chemical Reactions and Enzymes

59. Chemical Equations
Reactants are the things you start with (on the left side of the arrow)
Products are the things made from the reaction (on the right side of the arrow)

60. It takes ENERGY! Energy is needed to make the reaction happen
The activation energy is the minimum amount of energy needed for reactants to form products in a chemical reaction
Food takes energy to digest – it takes energy to get more energy out of it

61. Exothermic Reactions Exo=out thermic=heat (heat is energy!)
This reaction is exothermic and released heat energy
The products have less energy than the reactants

62. Endothermic Reactions
Endo=in
absorbs heat energy
Takes more energy to make the reaction go since it’s storing that energy
The energy of the products is higher than the energy of the reactants

63. Catalyst
substance that lowers the activation energy needed to start a chemical reaction
Less activation energy, means easier to do reaction and maybe faster
It does not increase how much product is made and it does not get used up in the reaction.

64. Enzymes Biological catalysts! (usually a protein)
This is what living things use to help reactions go that are needed
This is why some people can’t drink milk – they don’t have the enzyme

65. Enzymes
The reactants (molecules) that bind to the enzyme are called substrates
The specific location where a substrate binds on an enzyme is called the active site

66. Changing Enzymes
The active site changes shape, which helps chemical bonds in the reactants to be broken and new bonds to form for the products…LIKE A LOCK AND KEY!
Factors such as pH, temperature, and other substances affect how well enzymes work
Denature