1
Biology 12Biology 12Molecules of Life – organic biochemistryMolecules of Life – organic biochemistry
To be considered organic, molecules must contain
Carbon and Hydrogen atoms.
Practice; organic or not? CH4
H2O CO3
C6H12O6
Yes
Yes
No
No
2
Molecules of lifeMolecules of life
•Dalton’s theory of the Atom states that all matter is made of atoms. Hence, all organic life is made of atoms.
•The atoms that are most important to life are;
¤Carbon (C)
¤Oxygen (O)
¤Hydrogen (H)
¤Nitrogen (N)
¤Sodium (Na)
¤Chlorine (Cl)
¤Phosphorous (P)
¤Potassium (K)
*There are many others need for life but these are the major ones.
3
CarbonCarbon
Carbon’s ability to form up to 4 Carbon’s ability to form up to 4 covalent bonds with other atoms covalent bonds with other atoms allows for the creation of a variety allows for the creation of a variety of geometric structures.of geometric structures.
4
IsomersIsomers
Molecules with the same chemical Molecules with the same chemical formula but with a different formula but with a different arrangement of atoms.arrangement of atoms.
Isomers possess different shapes Isomers possess different shapes and different physical and and different physical and chemical properties.chemical properties.
There are 2 types of isomers:There are 2 types of isomers:
5
1. Structural isomers1. Structural isomers
Their atoms are linked together Their atoms are linked together differently. Example: Glucose and differently. Example: Glucose and Fructose (Formula for both is Fructose (Formula for both is CC66HH1212OO66))
6
2. Sterioisomers2. Sterioisomers
the bond structure is the same, but the bond structure is the same, but the geometrical positioning of the geometrical positioning of atoms and functional groups in atoms and functional groups in space differs. For example glucose space differs. For example glucose and galactose.and galactose.
7
Functional groupsFunctional groups
These groups are hydrophilic and These groups are hydrophilic and typically polar with the exception typically polar with the exception of the phosphate group and of the phosphate group and therefore increase the solubility of therefore increase the solubility of the organic molecule to which they the organic molecule to which they are attached. Ex: the hydroxyl (-are attached. Ex: the hydroxyl (-OH) in ethanol OH) in ethanol
8
MacromoleculesMacromolecules
Small molecules can join together to Small molecules can join together to form larger structures called form larger structures called macromolecules.macromolecules.
They are formed of long chains called They are formed of long chains called polymerspolymers
The molecular sub-units of a polymer The molecular sub-units of a polymer chain are called monomerschain are called monomers
Ex: carbohydrates, proteins, lipids Ex: carbohydrates, proteins, lipids and nucleic acids and nucleic acids
9
Molecules of LifeMolecules of Life
Two major reactions will build Two major reactions will build them up (anabolism) or degrade them up (anabolism) or degrade them (catabolism)them (catabolism)•Condensation and Hydrolysis are used to break down and form and other molecules of life.
10
1. Condensation1. Condensation
• When two monosaccharides combine to form a disaccharide one loses 1H and the other loses 1H and 1O.
• The 2H and 1O join to form 1 water molecule.
• This release of H2O is called condensation.
11
Molecules of LifeMolecules of Life
A. Condensation Reaction create the polymer chains.
Water moleule
12
Molecules of LifeMolecules of Life
B. Hydrolysis: the breaking down of molecules by adding
water
13
Molecules of LifeMolecules of Life Divided into 4 categories. Divided into 4 categories.
The four major molecules necessary for life are lipids, carbohydrates, proteins and nucleic acids.
14
CarbohydratesCarbohydrates
glucose
15
Molecules of LifeMolecules of Life
Carbohydrates:•composed of C,H, and O. (ratio of 2H to 1O)
•Primary source of molecular energy.
•Produced by plants in the form of simple sugars (glucose, fructose, galactose) and polysaccharides (starch, cellulose).
•Simple sugars (ie. Glucose monomer) C6H12O6 are called monosaccharides
•Two glucose molecules form a disaccharide.
•More than two sugar molecules joined make a polysaccharide.
16
LipidsLipids
triglyceridetriglyceride
17
Molecules of LifeMolecules of Life
LIPIDS:
•composed of C,H,and O (ie. C57H110O6)
•they are used in storing excess energy long term, and building of the cellular membrane. They help in the transmission of messages in the body as well.
•Produced by both plants and animals as fats, oils, waxes and steroids.
•Composed of fatty acid subunits attached to a glycerol (triglyceride) or other organic compound
18
ProteinsProteins
R group
Amino acid
19
Molecules of LifeMolecules of Life
Proteins:•composed of C, H, O and N (nitrogen is a necessary element for forming amino acids, the building blocks of proteins)
•a single protein may be formed from 100’s of amino acid monomers
•two amino acids make a dipeptide
•more make up a polypeptide
•Enzymes and hormones are examples of polypeptides. Enzymes are catalysts for chemical reactions.
•The type of polypeptide formed depends on the number and sequence of the amino acids that make it.
(there are 20 different amino acid groups).
20
Nucleic AcidsNucleic Acids
21
Molecules of LifeMolecules of Life
Nucleic Acids: composed of subunits called nucleotides.
DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
These acids form the code that controls an organisms basic behavior and appearance.
ATP is a nucleotide used to drive virtually all the energy in a cell.