Transcript Biochemistry Notes - Madeira City Schools

Biochemistry: the chemical makeup of living things
Honors Biology: Chapter 3
A. General Information
1. There are 4 classes of compounds found in living things
a. Carbohydrates – “sugars and starches”
b. Lipids – “fats”
c. Proteins – “enzymes, hormones,…”
d. Nucleic acids – “DNA, RNA”
2. Carbon is the main element in all of the above classes
a. needs 4 electrons to be stable (ie…can bond 4 times)
b. forms covalent bonds
3. Terms
a. Monomer – simple molecule, that when repeated,
builds a bigger molecule
b. Polymer – the big molecule that is made from
repeated monomers.
c. Dehydration Reaction – name of the reaction when a
polymer is made
Monomer + Monomer + ……  Polymer + water
d. Hydrolysis – name of the reaction when a polymer is
broken into many monomers
Water + Polymer  Monomer + Monomer + …
A. Carbohydrates – “sugars and starches”
1. made of Carbon, hydrogen, and Oxygen
2. the monomer is a monosaccharide: examples:
a. Glucose – plants make through photosynthesis
b. Galactose – found in milk
c. Fructose – found in fruit
3. all monosaccharides have the formula C6H12O6
4. they are “isomers” – they have the same formula, but
different arrangement of atoms
5. Dissacharides: when 2 monosaccharides bond
a. glucose + glucose  Maltose + water
b. glucose + galactose  Lactose + water
c. glucose + fructose  Sucrose + water
6. Polysaccharides: when many monosaccharides bond
a. starch – how plants store extra glucose
b. glycogen – how animals store extra glucose
c. cellulose – found in cell walls of plants
Glucose
sucrose
B. Lipids – “Fats, oils, waxes, and steroids”
1. made of Carbon, Hydrogen, and Oxygen
2. the monomer is a fatty acid
a. drawing of a fatty acid:
b. hydrophobic = water fearing (hydrocarbon end)
c. hydrophilic = water loving (carboxyl group)
3. Saturated Fat – the hydrocarbon chain is saturated with
hydrogens…therefore there are no
double bonds in the chain
a. can solidify because molecules can get close enough
b. these are the “bad” ones
c. drawing:
4. Unsaturated Fat – double bonds are in the hydrocarbon
chain
a. can’t solidify because the double bonds cause “kinks”
b. drawing:
Triglyceride
Steroid -- Cholesterol
C. Nucleic Acid
1. made of Carbon, Hydrogen, Oxygen, Nitrogen and
Phosphorous
2. The monomer is a nucleotide
3. Polymers are DNA (holds the recipes to make protein)
and RNA (helps to make the protein)
D. Proteins
1. Made of Carbon, Hydrogen, Oxygen, and Nitrogen
2. The monomer is an amino acid
3. There are 20 amino acids that our bodies use to make all
of our proteins
4. Types of proteins:
Amino Acids
Amino Acids
4. There are 4 levels of structure that go into determining
the shape of a protein
a. Primary Structure – amino acid sequence
**This is what determines the 3D conformation
b. Secondary Structure – coils and folds made by
polypeptide chain
**Coils caused by hydrogen bonds at regular
intervals along the polypeptide chain
**Alpha helix – coil held together by H-bonding
between every 4th amino acid
**Pleated sheet – two regions of the polypeptide
chain lie parallel to each other
c. Tertiary Structure – the overall, 3D shape of the
polypeptide
**most are described as “globular” or “fibrous”
**results from the interactions between the R
groups
**Hydrophobic interaction – type of bonding that
causes the tertiary structure
**Disulfide bridges – strong covalent bonds that
reinforce the protein conformation. Form when two
cystein monomers are close together.
d. Quaternary Structure – overall structure that results
from the combination of more than one polypeptide
folded chain.
** Not all proteins have this structure
**Collagen and Hemoglobin are examples
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
4. Enzymes – a type of protein that speeds up a reaction
a. weakens chemical bonds to make them easier to break
b. very specific to what molecule (substrate) it works on
c. things can affect how well enzymes work (lab)
**Concentration of enzyme
**Temperature of environment
**pH of environment
**Enzyme inhibitors (poisons, antibiotics)
Competitive inhibitors – block substrate from
entering active site
Allosteric inhibitors – bind to another part of the
enzyme causing it to change
shape and therefore
unreceptive to the substrate
Noncompetitive inhibitors – bind to another part of
the enzyme causing it to
change shape, but not so much
that a reaction can’t take place.
Reaction occurs, just slower.
5. Hormones – a type of protein that regulates body functions