Biochemistry
A. Basic Chemistry
1. Atom – smallest particle of an element that has the characteristics of that element
3 parts
a. protons (+) inside the
b. neutrons (0) nucleus
c. electrons (-) orbiting nucleus
2. Element – substance that cannot be broken down
a. ex : C, H, O, Na
3. Compound(com = with/together)– substance
composed of 2+ elements chemically combined
a. ex : H2O (water), C6H12O6 (glucose), NaCl (salt)
B. Bonds – 4 main kinds
1. ionic bonds – forms when electrons are transferred between atoms
2. covalent bonds (com = with/together) – forms when atoms share electrons
3. hydrogen bonds – a weak bond formed between a H+ and a (-) atom
4. peptide bonds – forms between amino acids to form a protein
C. Properties of Water
1. water is Polar – has unequal charges
2. water has a High Specific Heat Capacity – resists temperature change
3. water is Cohesive – water molecules stick to each other to create surface tension
4. water is Adhesive – water molecules stick to other surfaces
5. water is the Universal Solvent – dissolves other particles (solutes)
D. Acids and Bases
1. Acid – pH below 7
2. Base – pH above 7
3. Neutral – At pH 7
4. Buffers – solutions added to maintain
a pH level
a. if a solution becomes too acidic,
a basic solution will be added
b. if a solution becomes too basic,
an acidic solution will be added
E. Definitions
1. Monomor- (mono = 1 ) - single unit
2. Polymer (poly – many) – large molecule made up of monomer units bonded together
F. Making and Breaking Bonds
1. Condensation Reaction (aka Dehydration Synthesis)
a. bonding of 2 monomers together
b. whenever a bond is formed water is formed
c. one molecule releases an –OH while the other
releases an –H
2. Hydrolysis (hydro = water, lysis = to break/dissolve)
a. breaking of bonds within a polymer
b. water is absorbed
c. one molecule gains an –OH while the other
gains an -H
G. Organic Chemistry
1. Organic – contains C and found in living things
(CO2 – exception to this rule)
2. Most common elements in living things : C, H, O, N, P, and S
3. 4 kinds of organic compounds : carbohydrates, lipids, proteins, and nucleic acids
H. Carbohydrates
1. contains C, H, and O in a 1:2:1 ratio
2. monomer unit : monosaccharides(mono = 1, saccharo – sugar) –short-term / primary
energy source
Examples:
a. glucose - C6H12O6 – short term energy in all living things
b. fructose - C5H10O5 – found in fruit
c. ribose / deoxyribose - C5H10O5 - found in RNA and DNA
d. drawing of glucose –
3. disaccharides(di = 2, saccharo – sugar)- contains 2 monosaccharides combined
together through condensation reaction
a. chemical formula : C12H22O11
- explanation : C6H12O6 + C6H12O6 = C12H24O12
– H2O
C12H22O11
Examples
b. sucrose – table sugar = glucose + fructose
c. lactose – milk sugar = galactose + glucose
d. maltose = glucose + glucose
4. polysaccharides – (poly = many, saccharo = sugar) – contains many monosaccharides
bonded together through condensation reaction
Examples
a. starch – how plants store glucose after photosynthesis
b. glycogen – how animals store glucose in the liver
c. cellulose – makes up plant cell wall – not digested by animals
d. chitin – makes up cell wall in fungi
5. indicators – a chemical used to test the composition of another substance
a. iodine – changes from yellowish to dark blue
in the presence of a starch
b. Benedict’s solution – changes from blue to orange
in the presence of a monosaccharide
I. Lipids
1. contains C, H, and O
2. examples : fats, oils, and waxes
3. lipids are insoluble in water (hydrophobic, hydro = water, phobia = fear of))
4. Functions of lipids
a. insulation
b. long term energy storage
5. Monomer units : 1 glycerol and 3 fatty acids
6. Drawing of a lipid
7. Steroid – lipid in a double ring structure
a. function in gender hormones, metabolism, muscle and bone synthesis
8. Phospholipids – lipids with phosphates attached
that make up the cell membrane
9. Indicator – paper becomes translucent in the presence
of lipids
J. Proteins
1. contains C, H, O, N
2. monomer unit : amino acids
3. amino acids
a. only 20 different kinds of amino acids
b. different arrangement of amino acids
in a chain produces different proteins
c. amino acids are bonded together with
peptide bonds
d. drawing an amino acid
4. functions of proteins
a. growth and repair of cells
b. make antibodies that fight disease (immune support)
c. make up hormones
d. facilitate heredity
e. speed up chemical reactions (only special proteins called enzymes)
5. Examples of proteins
a. melanin – protein responsible for skin and hair pigmentation
b. hemoglobin – protein in blood that carries oxygen
c. insulin – protein responsible for maintaining glucose levels in the blood
d. amylase – protein in saliva that breaks down starch
6. folding of protein structure is related to the function of protein
7. Indicators - Biuret solution changes from blue to orange in the presence of a protein
K. Enzymes
1. specific type of protein that acts as a catalyst (speeds up chemical reactions)
2. enzymes lower the activation energy (amount of energy required for a reaction to begin)
3. each enzyme is specific and works on only one kind of substrate
4. active site of the enzyme must match the shape of the
substrate (lock and key model)
5. Steps in enzyme functioning
a. substrate attaches to enzyme at active site forming enzyme-substrate complex
b. enzyme completes the reaction – breaking down substrate or building up substrate
c. enzyme release products and is ready to be reused
6. enzymes are reusable
7. enzymes names end in –ase and are usually named after substrate (ex : lipase – enzyme,
lipids – substrate)
8. 3 factors that affect enzyme functioning :
a. temperature
b. pH
c. substrate concentration
9. Extreme temperatures or pH can cause enzymes to change shape of the active site = denaturation
L. Nucleic Acids
1. Contain C, H, O, N, and P
2. Ex : DNA (D = deoxyribose) and RNA (R = ribose)
3. monomer unit – nucleotides
4. nucleotides – 3 parts
a. 5 carbon sugar
b. phosphate (PO4)
c. Nitrogen Base
1. DNA : A-T, G-C
2. RNA : A – U, G-C
5. drawing of a nucleotide
6. Drawing of a DNA strand
7. DNA shape is really a double helix – twisted ladder
8. function of nucleic acids
a. DNA and RNA carry genetic information to code
for proteins