Download biomolecule

Biochemistry
An Introduction to the Chemistry of
Life for Biology Students
Composition of living matter
 “Living things are composed of lifeless
molecules” (Albert Lehninger)
 “Chemistry is the logic of biological
phenomena” (Garrett and Grisham)
 Organisms are complicated and highly
organized
 Biological structures serve functional purposes
 Living systems are actively engaged in energy
transformations
 Living systems have a remarkable capacity for
self-replication
Biomolecules:
The Molecules of Life
H, O, C and N make up 99% of atoms in the
human body
ELEMENT PERCENTAGE
Oxygen
63
Hydrogen 25.2
Carbon
9.5
Nitrogen
1.4
Common in biosystems
Carbon (C)
Oxygen (O)
Hydrogen (H)
 What property unites H, O, C and N and
renders these atoms so appropriate to the
chemistry of life?
 Answer: Their ability to form covalent bonds
by electron-pair sharing.
Types of chemical bonds
Covalent bonds
• Common in
biosystems
• Share a pair of
electrons
Ionic Bonds
• Transfer
an
electron
• Opposite
charges attract
Types of Chemical Bonds
Hydrogen bonds
• Weak partial bonds
• Water surface tension
Van der Waals forces
Weak
Functional groups
Simple Molecules are the Units for
Building Complex Structures
 Metabolites and Macromolecules
 Organelles
 Membranes
 The Unit of Life is the Cell
Primary Organic Compounds
(macromolecules)
You are expected to
learn the structure
and functions of
these organic
compounds:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
Polymers ands Monomers
 Each of these types of molecules are
polymers that are assembled from single
units called monomers.
 Each type of macromolecule is an
assemblage of a different type of monomer.
Monomers
Macromolecule
Carbohydrates
Monomer ( biomolecule)
Monosaccharide
Lipids
Proteins
Not always polymers;
Hydrocarbon chains
Amino acids
Nucleic acids
Nucleotides
How do monomers form polymers?
 In condensation reactions (also called
dehydration synthesis), a molecule of water is
removed from two monomers as they are
connected together.
Hydrolysis
 In a reaction opposite to condensation, a
water molecule can be added (along with the
use of an enzyme) to split a polymer in two.
Properties of Biomolecules
 Macromolecules and Their Building Blocks
Have a “Sense” or Directionality
 Macromolecules are Informational
 Biomolecules Have Characteristic ThreeDimensional Architecture
 Weak Forces Maintain Biological Structure
and Determine Biomolecular Interactions
Cell hierarchy
 Biomolecules combine to form
macromolecules.
 And macromolecules combine non covalently
to form supramolecules, such as:
Supramolecule
Biomolecules
Biomolecule
Lipo proteins
lipids
proteins
Ribosomes
Nucleic acids
proteins
Glycolipids
Sugar
lipids
Cell hierarchy
 Finally, at the higher level of organization of
the cell structure, supramolecules are further
assembled into call organelles. ( Nuclei,
mitochondria, chloroplasts, etc..)
Macromolecules:
a) Carbohydrates
 Carbohydrates are made of carbon,
hydrogen, and oxygen atoms, always in a
ratio of 1:2:1.
 Carbohydrates are the key source of energy
used by living things.
 The building blocks of carbohydrates are
sugars, such as glucose and fructose.
Carbohydrates
 What do the roots
mono-, di-, oligo-, and
poly mean?
 Each of these roots
can be added to the
word saccharide to
describe the type of
carbohydrate you
have.

How do two monosaccharides
combine to make a
polysaccharide?

Polysaccharides
Lipids
 Lipids are molecules that consist of long
hydrocarbon chains. Attaching the three
chains together is usually a glycerol molecule.
Lipids are NONpolar.
Saturated vs. Unsaturated
Fat

Proteins
 Proteins are building blocks of structures
called amino acids. Proteins are what your
DNA codes to make .
 A peptide bond forms between amino acids
by dehydration synthesis.
Protein Structure
Level
Primary
Secondary
Tertiary
Quaternary
Description
The amino acid sequence
Helices and Sheets
Disulfide bridges
Multiple polypeptides
connect