Bio A - Biochemistry
Chemistry of Life notes
1. Organic Molecules: molecules that contain both Carbon and Hydrogen (C and H); can contain
other elements too;
- IF THEY CONTAIN ONLY C AND H then they can ALSO be called
hydrocarbons.
What is so cool about carbon?
Carbon has _four valence electrons which means it can form 4 bonds AND can bond with itself.
- This means it can form long chains, rings, branched chains and many other molecules
Inorganic molecules : molecules that do NOT contain both C and H
WATER: most essential inorganic molecule
 Body is 65- 75% water on average
 More water in fat or muscle?? MUSCLE Why? Fat is hydrophobic
 More water in Males or females?? Males Why? Males have less fat than females
Functions of water:
 Solvent: dissolves lots of stuff (salts especially)
 Medium: where the chemical reactions happen
 Moistens Surfaces: lungs, mouth, nasal passages
 Temperature Regulation: an example is sweating (keeps internal temperature from getting too high)
 Cushion - Brain in skull;
 Transportation: moves nutrients and other materials through the body (blood is mostly water!)
 Lubrication: in your Joints; prevent bones from scraping
 Hydrolysis: type of chemical reaction that uses water to break apart large molecules
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Bio A - Biochemistry
 Sense Organs: nose, mouth, eyes
Important minerals: Where are they important?
Iron:
BLOOD
Calcium and phosphorus: BONES
Sodium, potassium and Chlorine: NERVES
Iodine: THYROID GLAND
 Function of minerals: help to maintain fluid and electrolyte (ion) balance
o act as a pH buffer (phosphate)
o aid in structure of cells and the body (calcium and phosphorus)
o move nerve impulses (sodium, potassium and chlorine)
o carry oxygen (part of the hemoglobin molecule in blood)
o helps to regulate metabolism and the thyroid gland (iodine)
Minerals and water are NOT ORGANIC, but they ARE IMPORTANT in living things. Reactions and
movement of water, and electrical impulses cannot take place without water and minerals!
ORGANIC MACROMOLECULES
The four large organic molecules we will study are known as MACROMOLECULES
Macro means BIG
- made up of many small molecules linked together to form one big molecule
- small molecule = a MONOMER
- chain of small molecules (linked together) = POLYMER
Nutritional Compounds: These Macromolecules are what provide us with ENERGY AND NUTRIENTS
THEY MAKE UP THE CALORIES WE EAT
Calorie (in chemistry) is the amount of energy it takes to raise the temperature of 1 gram of water 1 degree
Celsius;
1 food calorie = 1000 chemistry calories = 1 kilocalorie
So if we eat 100 calories, it means our body gets 100 kCal of energy from that food!
Carbohydrates contain 4 calories per gram of food
Lipids contain 9 calories per gram of food
Proteins contain 4 calories per gram of food. NUTRITION CHART
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Bio A - Biochemistry
We will study the four major classes of macromolecules: Carbohydrates, Lipids, Proteins and Nucleic acids
CARBOHYDRATES:
The monomer of a carbohydrate is called a MONOSACCHARIDE
What elements are carbohydrates made of? Carbon, Hydrogen, Oxygen (CHO)
What shape do these molecules have? Hexagon or pentagon (the picture below shows one glucose and one
fructose joined together to make sucrose)
Define:
Disaccharide:DOUBLE SUGAR: two monosaccharides joined together : EXAMPLES sucrose, lactose
There are other disaccharides as well.
Polysaccharide: 3 or more monosaccharides (single sugars joined together
A huge chain of molecules
Polysaccharides actually have 100s of glucose molecules – this is just an illustration
HOW DO POLYSACCHARIDES FORM? MONOSACCHARIDES JOIN TOGETHER USING A
PROCESS CALLED:
dehydration synthesis
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Bio A - Biochemistry
Dehydration synthesis: A chemical reaction that joins monomers to make polymers
-
2H’s and one O have to be removed from the reactants to connect them. These atoms then become
WATER (H2O) . This same reaction will be used to build carbs, lipids, proteins and nucleic acids
Below is the dehydration synthesis reaction that connects two monosaccharides into a disaccharide.
-
Highlight the atoms that become the water molecule
Hydrolysis: a chemical reaction that takes in water (H2O) to break apart polymers  monomers
- Requires the addition of ONE water molecule.
- this same reaction will be used to break down carbs, lipids, proteins and nucleic acids
- Hydrolysis is the exact reverse of dehydration synthesis shown above!
What do Carbs do for us?
Function
General Name:
Examples
Instant energy
Monosaccharides (simple
sugars)
glucose, fructose
Short term energy storage
Polysaccharides
Glycogen (animals)
Starch (plants)
Cell structure (plant cell walls)
Polysaccharides
Cellulose (becomes fiber in
our diet when we eat plants!)
What do the formal names of carbs all have in common?
They all end in OSE (glucose, fructose, cellulose, amylase, etc
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Bio A - Biochemistry
LIPIDS: There are MANY TYPES OF LIPIDS
One type of lipid molecule is made of 1 glycerol and 3 fatty acids
This type of lipid molecule is called a triglyceride
Do lipids have a true monomer? NO why? Because triglycerides no more than 3 fatty acids can be
added to a glycerol. And fatty acids don’t join to each other, they join to a glycerol
What reaction puts a triglyceride together? _Dehydration synthesis
What reaction breaks apart a triglyceride? _Hydrolysis
Highlight the atoms that become the water molecules. Then fill in how many waters are made
H
+
H
+
3 H2O
H
Three Fatty Acids
1 Triglyceride
Lipids are made of the following elements: CARBON, HYDROGEN, OXYGEN
Some examples of lipids include: _FATS, OILS, WAXES, STEROIDS
The major functions of lipids are:
1.
LONG TERM ENERGY STORAGE
2. CELL STRUCTURE (the Cell Membrane)
3.
CUSHIONING
4.
INSULATION
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Bio A - Biochemistry
PROTEIN:
The monomer of a protein is called an _______amino acid_______
What reaction builds proteins by linking amino acids? ___dehydration synthesis_______
What reaction breaks down proteins into amino acids? ______hydrolysis__________
Below is a dehydration synthesis reaction of two amino acids:
- highlight the atoms that become the water molecule
-
label the amino and carboxyl ends of AA 1
label the “variable R” group
label the peptide bond
+
+
H2O
How many different types of Amino acids exist? __20__
The _____R group________ is different in each amino acid while the amino group and carboxyl group
are the same.
Proteins are made of the following elements____CHON(S)___________
Once amino acids are linked in a chain, they are called a polypeptide. What has to happen to the
polypeptide before it becomes a functional protein?
Functions of Proteins and examples
Function
Examples
Structure
Cartilage
Chemical Messengers
Hormones
Speed up chemical reactions
Enzymes
Fight disease
Antibodies
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Bio A - Biochemistry
NUCLEIC ACIDS:
Nucleic acids are made up of the monomer called ____nucleotide_________
Draw the structure of one monomer and label the THREE parts; include the variations:
Nucleic acids are made of the elements___________CHNOP______________
What is the general role for all nucleic acids: ___________store information_________________________
Compare and contrast RNA and DNA, the two types of nucleic acids.
RNA
DNA
Full Name
Ribonucleic Acid
Deoxyribonucleic acid
Name of the
sugar
RIBOSE
DEOXYRIBOSE
Possible nitrogen
Bases
GCAU
How many
chains or strands
does it have?
One
Function
-
Contains the directions to
make 1 protein; temporary
copy
GCAT
two
DNA is the master copy of all
our information.
Stored in the nucleus of the cell
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Bio A - Biochemistry
Nucleic acid analogy: Nucleic acids are information molecules that teach our cells how to make proteins.
Use this analogy to help understand.
DNA is an ENTIRE COOKBOOK of recipes that contains the information to make EVERY protein your body
needs.
-
But let’s say you want to make cookies. Do you need the pot roast recipe in the same cookbook? Do you
need all the pie recipes? No!
-
So… we can copy the cookie recipe onto an index card and follow ONLY those directions.
Likewise, the cell can copy a single protein recipe from the DNA into RNA.
-
If you follow the cookie recipe you will end up with one batch of tasty cookies.
Likewise, if your cells follow the directions on the RNA it will make a single protein
-
After finishing the cookies, we can throw out the index card because we still have that recipe in the
cookbook.
Likewise, after making the protein, the temporary copy of the recipe (RNA) can be destroyed because there
is still a master copy in the DNA!
-
Each protein recipe in the DNA is called a Gene
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