Biochemistry
Matter & Elements
•All matter made of elements (atoms)
•All atoms have structure
•Protons/electrons/neutrons? Charge? Mass? (Chart)
•# of protons in nucleus determines atom’s identity
•Ions atoms that gain or lose electrons
Hemoglobin
Atom
Atomic Structure
Protons carry a +1 charge, mass of 1 AMU
Neutrons carry a 0 charge; mass of 1AMU
Electrons  carry a –1charge; mass of 0 AMU
Nucleus  consists of protons and neutrons; central part
of the atom
Electrons  move around the nucleus
Why Atoms Form Bonds
•2 or more elements = compound
•1st 20 elements have up to 3 energy levels/ 2 electrons on
1st level, up to 8 on 2nd level, and 8 on the 3rd level
•Most elements want to have 8 electrons in outer shell
•Atoms will share or steal to get 8 electrons in outer shell
•Sharing electrons covalent bonds
•Stealing electrons ionic bonds
Covalent Bond In Action
Ionic Bond In Action
NaCl- Ionic Bond
CH4- Covalent Bond
Chemical Changes, Chemical
Symbols, & Formulas
Chemical Symbols- look at P.T.
Chemical Formulas group of symbols together
Exp. H2O, CO2, 5H2O
Acids and Bases
Pure water has equal amounts of H+ and OHIf equal number of H+ and OH-, solution is neutral
pH Scale
Scale measures amount of H+ ions
in solutions
pH = 7-neutral
pH< 7 –acidic
pH > 7--basic
Polarity of Water
Structure of water is VERY unique
H2O
•Oxygen has 8 protons & 8 electrons
•Opposites attract, and electrons are pulled in close to the
nucleus
•Hydrogen has 1 proton & 1 electrons
•Not held together very closely
Water’s Structure
•In H2O, Oxygen slightly pulls the electrons away from
the 2 Hydrogen molecules
•Oxygen becomes partially negative
•Hydrogen becomes partially positive
•Water is a POLAR molecules (slightly charged)
•Polarity makes water stick together
Polarity of Water
Polarity of Water
Physical Properties of water
•Ice floats
•Water absorbs and retains heat
•Water molecules stick to each other
•Water molecules stick to other polar
substances
Ice floats:
•When water freezes, hydrogen bonds lock
water molecules into a structure that has empty
spaces, making it less dense than liquid water
Water absorbs and retains heat
Because of hydrogen bonds, water can absorb large
amounts of energy
Absorbs lot of heat before it boils
Helps keep cells at an even temperature despite
changes in the environment – homeostasis again!!
Allows large bodies of water to maintain a relatively
constant temperature.
Energy
In living organisms, energy is stored as chemical,
mechanical, and thermal energy
Types of Energy
Potential Energy – stored energy; energy of position
Kinetic Energy- Energy of motion
Law of Conservation of Energy- energy is not created
or destroyed in a chemical reaction (1st Law of
Thermodynamics)
Energy & Chemical Reactions
Reactants = substances that begin a chemical reaction
Products = substances that are made from a chemical
reaction
A + B  AB
Reactants
Products
Different Types of Reactions
Exergonic Reaction = releases energy
Endergonic Reaction = absorbs energy
Oxidation Reactions = reactant loses electrons
Reduction Reaction = reactant gains electrons
Organic Examples
Carbohydrates
•provide energy to cells
•help build cell structures
•monosaccharides= 1 sugar unit
•disaacharides = 2 connected sugar units
•polysaccharides = more than 2 connected sugar units
Glucose- The Ultimate Carbohydrate
Lipids
Fats (triglycerides)
Used for energy
Long chain molecules
Triglyceride = 3 FA’s + glycerol
Saturated= not easily broken down (all single bonds)
Unsaturated= easily broken down (double bonds)
The Phospholipid Bilayer
Proteins
THE structural material of the body!
1. Hormones
2. Receptors
3. Enzymes
Made from Amino Acids (connected via peptide bonds)
Collagen
Hemoglobin
Levels of organization:
Keratin-The Protein
of Hair and
Fingernails
Hemoglobin = Transport Protein
Nucleic Acids
•Make our genes
•Instruct body which proteins to make
•Made from nucleotides
•DNA + RNA