Download Biochemistry Notes - Okemos Public Schools

Biochemistry Notes
What are we made of?
How do we obtain energy?
We are what we eat….or are we?
I.
Chemistry & Organic Chemistry
A. Structure of Matter (living or nonliving)
1. Anything that has mass and takes up space is considered matter.
2. Matter is composed of atoms. (element = 1 type of atom
(compound = 2 types atoms or more)
3. Atoms can join chemically by sharing electrons. Covalent bonds.
4. Atoms can join chemical by transferring electrons, becoming
oppositely charged and attracting each other. Ionic bonds.
5. Bonds between atoms store energy.
6. Over 90% of us is C, N, O, and H
7. Our bodies convert food into usable biological molecules.
B. Why Carbon?
1. C is central element of life because most biological molecules
are built on a C framework.
2. Molecules containing C are called “organic molecules.” (no C =
inorganic molecules.)
3. Carbon has 4 valence electrons so can form 4 covalent bonds,
forms bonds easily with itself and other elements.
4. 3 types of C
molecules
Straight C chain
Branched C chain
C ring.
5. A single bond consists of 2 shared electrons.
6. A double bond consists of 4 (two pairs) shared electrons.
7. A double bond consists of 6 (three pairs) shared electrons.
C. Structures of Carbon Molecules
II.
Polymers
A. What are polymers?
Large C molecules that consist of repeating, linked units.
Also called macromolecules if large.
Each unit is called a monomer
B. How are polymers synthesized?
Monomers combine by releasing a water molecule at each bond.
Called a condensation reaction.
C. How are polymers taken apart?
Water molecules are used to break each monomer apart.
Called a hydrolysis reaction.
III.
The Four Main Classes of Organic Molecules
A. Carbohydrates,
B. Lipids,
C. Proteins,
D. Nucleic Acids
IV.
Carboyhdrates 3 types
A. Facts
1. made of sugars (the monomers)
called monosaccharides.
2. composed of C, H, & O
3. 1 C, for 2 H’s for every O
4. Names end in “ose.”
B. Simple Carbohydrates—Mono or Disaccharides
1. Monosaccharide examples: (all isomers.)
Glucose—main source of energy for cells. Quick energy. Stored
carbohydrates breakdown into units of glucose when we need
energy.
Fructrose: fruit sugars, sweetest.
Galactose: milk sugar
5. Disaccharide examples: (2 bonded sugars)
Combine by a condensation rxn.
Lactose = glucose + galactose= lactose (milk sugar again.)
Glucose + glucose = maltose (malt sugar)
Glucose + fructose = sucrose (table sugar)
C. Complex carbohydrates-- Polysaccharides
1. Polysaccharide examples ( 3 or more, sugars bonded together)
Made by many condensation reactions
Animals store extra sugar in highly branched chain
polysaccharide called glycogen.
Stored in liver and muscles.
Broken down into glucose when energy is needed quickly.
Plants store sugars in branched and unbranched chains
called starch.
Plants also store sugars as polysaccharide cellulose—long
straight chains that give strength to cell wall
Insects create a polysaccharide called Chitin which makes
up their exoskeleton.l
V.
Lipids
A. Facts
1.
2.
3.
4.
Contain C, H, & O
More C bonds than carbs so can be used for more energy
Used mainly as reserve energy supply.
consists of molecule called glycerol and monomers =
hydrocarbon units that connect to make fatty acid chains
5. Fatty acid chains (tails) attach to glycerol (head) through
dehydration synthesis/condensation rxns and unattach through
hydrolysis.
B. types of lipids.
1.
Triglycerides—Fats & Oils
a. consist of 3 Fatty acids and 1 glycerol
b. bonds store lots of energy
c. easy to store and maintain, require little water (15%)
Saturated triglycerides/fats contain all single bonds in the
fatty acid tails (C’s are saturated with bonds.
d. Reserve energy supply
e. provides cushion
f. prevents heat loss
g. coats nerve cells, allows for nerve impulses
--solid at room temp
--raises bad cholesterol
--usually animal is source
Unsaturated fats/ triglycerides contain fa’s that have 1 or
more double bonds.
--liquid at room temp
--lowers bad and raises good cholesterol
--usually plant source—found in seeds/nuts—
energy for sprouting
--monounsaturated (1 dbl bond) or polysaturated
(more than 1 double bond.
2.
Phospholipids
a. 1 glycerol + 2 Fatty acids
b. Cell membranes are made of two layers of
phospholipids
VI.
3.
Waxes
a. 1 glycerol and 1 fatty acid
b. used for protection (ears)
4.
Steroids
a. consists of 4 C rings.
b. Make up many hormones
c. Help with fat metabolism—cholesterol
Proteins
A. Facts
1. Consist of C, H, O, & N
2. made of units (monomers) called amino acids or peptides
B. Amino Acids
1. 20 amino acids, 8 must come from the diet (essential)
2. All similar except for one area—the “R” group
3. amino acid example (peptide)
4. 1 AA = peptide
2 AAs= dipeptide
Many AAs = polypeptide
Protein = 1-4 polypeptides
 Polypeptides bend and fold into a unique
shape based on the amino acids in the chain.
 If the protein has the wrong shape due to
incorrect AAs, it will not function properly.
5.
amino acids combine and uncombined by dehydration
synthesis and hydrolysis reactions.
C. Functions of proteins
1. used to make or hold together all of our structures (hair, muscle
,skin, ligaments, tendon. organs, etc.)
2. direct and carry out most of the chemical reactions in our
bodies—Enzymes
3. Act as antibodies—“tag” foreign cells
4. Cell markers
5. Cell transport
6. Carry O2 on RBCs= hemoglobin
7. excess is excreted.last choice to break down for energy.
D. Nucleic Acids
1.
2.
3.
4.
Made of C, H, O, N, & P
Made of monomers called nucleotides
Store and transfer information used to run our cells.
Two types—DNA and RNA