BIOCHEMISTRY LECTURE

PREPARED BY: ROZALINA R. ADONIS, RMT, MSMLS

Overview
 Biochemistry is also referred as “chemistry of the living cell”
 Several historian were greatly known to contribute in the development of
biochemistry
 Biomolecules have 4 major classes namely: carbohydrates, lipids, amino
acid and nucleotides
 Functional groups of organic molecules is subdivided into three types:
hydrocarbons, compounds containing a single bond to a heteroatom and
compound containing a C=O group
 Biochemical process includes metabolism and energy transformations of ATP
 Biochemical reactions includes neutralization, hydrolysis, condensation and
oxidation-reduction.
Outline of Today’s Presentation
 Definition of terms
 Introduction in biochemistry
 Brief history of biological chemistry
 Differentiate biomolecules and the functional groups of
organic molecules
 Different biochemical processes and reactions
Definition of Terms
 Hydrophobic - lacking an affinity for water
 Hydrophilic - having an affinity for water
 Monomer - is a molecule that forms the basic unit for polymers, which are
the building blocks of proteins
 Dimer - consist of 2 monomer
 Polymer - is a chemical compound with molecules bonded together in
long, repeating chains
 Polar - occur when there is an electronegativity difference between the
bonded atoms
 Non-Polar - occur when electrons are shared equal between atoms of a
diatomic molecule
 Essential - amino acid that the body cannot synthesize on its own, so it must
be obtained from the diet
 Non-essential - amino acid that the body can synthesize on its own
BIOCHEMISTRY
 Defined as the application of chemistry to the study
of biological processes at the cellular and molecular
level.
 Referred as “chemistry of the living cell”
 HISTORY OF BIOCHEMISTRY
1665 – Robert Hooke invented the microscope.

1674 – Anton van Leeuwenhoek witnessed a live cell plant under microscope

1869 – Friedrich Miescher first identified “nuclein” inside the nuclei of human
white blood cells

1900 – Eduard Buchner introduced the concept of an “enzyme”

1903 – Carl Neuber coined the name Biochemistry

1919 – Phoebus Levene first discovered the order

of the three major components of a single
nucleotide
 HISTORY OF BIOCHEMISTRY
1937 – Hans Krebs discovered the process of Citric Acid Cycle (Krebs Cycle)

1950 – Erwin Chargaff says the amount of cytosine is equal to the amount of
guanine and the amount of thymine is equal to the amount of adenine
(Chargaff’s Rule)

1958 – Frederick Sanger discovered the first and complete protein structure
which is insulin.

1961 – Cracking of genetic code

1977 – Frederick Sanger had successfully

sequenced the genome of
bacteriophage which contained
more than 5000 nucleotides
Biological and the Functional
Groups of Organic Molecules
BIOMOLECULES FUNCTIONAL GROUPS
 Specific group of atoms or bonds within a
 Defined as substances compound that is responsible for the
that are produced by characteristic chemical reactions of that
cells and living organisms compound

 Carbohydrates  Examples are:

 Hydroxyl
 Lipids
 Methyl
 Amino Acids
 Carbonyl
 Nucleotides  Carboxyl
 Others such as vitamins  Amino
and heme  Phosphate
 Sulfhydryl
BIOMOLECULES
 CARBOHYDRATES
 One of the major groups of
biomolecules which is soluble
in water and is polar in nature
 Mainly used as an energy
source and commonly referred
to as sugars and starches
 It is composed of three (3)
elements: carbon (C),
hydrogen (H) and oxygen (O)
 It can range in size from very
small to very large.
 Can be classified in to
monosaccharide,
disaccharide and
polysaccharides.
 LIPIDS
 Relatively small water-
insoluble molecules and
nonpolar in nature
 Some lipids act as storage
molecules like
triglycerides stored in
adipose tissue
 Its building blocks are
fatty acids
 It act as hydrophobic
barrier of the cell
membrane that permits
the entry and exit of
certain molecules
 AMINO ACIDS
 A compound that contains
two functional groups – the
amino group and the
carboxyl group bonded to
the same carbon
 They are generally soluble
in water
 Some of them are polar
and nonpolar in nature
 Used to synthesize
hormones and make
proteins
 Can be classified as
essential and non-essential
 NUCLEOTIDES AND NUCLEIC ACID
 It is used mainly as the
building blocks for DNA
and RNA
 Individual nucleotides are
soluble in water
 They are polar and
nonpolar in nature
 It consists of a sugar
molecule (either ribose in
RNA or deoxyribose in
DNA) attached to a
phosphate group and a
nitrogen-containing base
 NUCLEOTIDES AND NUCLEIC ACID
 Double helix
structure  Single stranded
comprised of structure and
adenine (A), comprised
guanine (G), adenine (A),
cytosine (C) guanine (G),
and thymine cytosine (C) and
(T) uracil (U)
 Located in the  Copied from
nucleus of the DNA and is
cell and self- working form of
replicating the information
 Storage form  Made in the
of genetic nucleus and
information mRNA is exported
 Base pairing is to the cytosol
AT and GC  Base pairing is AU
and GC
FUNCTIONAL GROUPS
 Can be subdivided into three types
1. Hydrocarbons
2. Compounds containing a single bond to a
heteroatom
3. Compounds containing a C=O group
HYDROCARBONS  Compounds that contain only the
elements of carbon and hydrogen

Type of General Structure Example Functional Group

Compound

Alkane
(only C – C single R–H -
bond)
Carbon – carbon
Alkenes C=C double bond

Carbon – carbon
Alkyne –C=C– triple bond

Aromatic
Benzene ring
Compound
COMPOUNDS CONTAINING A  Always dissect it into small pieces to
SINGLE BOND TO A identify the functional group
HETEROATOM
 COMPOUNDS CONTAINING A C=O GROUP
 Many different kinds of compounds contain a carbon-oxygen double bond (C=O, carbonyl group)
 The type of atom bonded to the carbonyl carbon – hydrogen, carbon, or a heteroatom – determines the
specific class of carbonyl compound.
OTHER FUNCTIONAL GROUPS
BIOCHEMICAL PROCESSES

 Are the chemical processes that occur in living organisms, involving

biomolecules
 BIOCHEMICAL PROCESSES
 Metabolism is the totality of the chemical reactions which occur
within a cell, and can be divided into two types:
1. Anabolic reactions involve the synthesis of complex molecules from simpler
ones and usually require energy to form new bonds (endergonic)
2. Catabolic reactions involve the breakdown of complex molecules into
simpler ones and usually release energy from breaking bonds (exergonic)
 BIOCHEMICAL PROCESSES
 Energy Transformations
 Energy in living cells is stored and released in the chemical form of ATP (adenosine
triphosphate)
 ATP is made up of an RNA nucleotide (base = adenine) bonded to two additional phosphate
groups (three in total)
 These additional phosphates are connected by high energy bonds that release a large amount
of free energy when hydrolysed
 The energy released from the hydrolysis of ATP (into ADP + Pi) can be used by the cell to fuel
biochemical processes
 ATP can be synthesised by the transmembrane enzyme ATP synthase (via both photosynthesis
and cell respiration)
 Photosynthesis uses light energy to synthesise ATP, which is then hydrolysed in order to synthesise
organic molecules (anabolic reaction)
 Cell respiration breaks down organic molecules to release energy which is used to synthesise
ATP for use in cell processes (catabolic reaction)
 BIOCHEMICAL PROCESSES
 Functions of ATP
ATP provides an immediate source of energy when hydrolysed and
functions as the energy currency of the cell
 Biochemical processes that utilise ATP include:
1. Growth and repair: Increase cell size and replace damaged tissue
requires ATP
2. Movement: The contraction of muscle fibres in order to generate
movement in organisms requires ATP
3. Nerve transmissions: The generation and transmission of a nerve
impulse (action potential) requires ATP
4. Active transport: Moving molecules against their concentration
gradient, or by cytosis, requires ATP
5. Biosynthesis of macromolecules: Building complex organic
molecules from simpler subunits (anabolism) requires ATP
6. Emission of light: Some cells may be capable of luminescence, and
this process requires ATP
BIOCHEMICAL REACTIONS
 Chemical reactions associated with biological processes
 Four main types of reactions are:
1. Neutralization
2. Hydrolysis
3. Condensation
4. Oxidation-Reduction
 BIOCHEMICAL REACTIONS
NEUTRALIZATION
 Interaction of an acid and  Buffers: resist changes in
base to form a salt (ionic pH
compound) and water  Release H+ ions when fluid
 Necessary to maintain is basic
constant pH state within the  Take up H+ ions when fluid
body is acidic
 BIOCHEMICAL REACTIONS
HYDROLYSIS  Involves the reaction of an organic chemical with
water to form two or more new substances and
usually means the cleavage of chemical bonds
by the addition of water.
 BIOCHEMICAL REACTIONS
CONDENSATION  Reaction in which two molecules
combine to form a single molecule

The condensation (dehydration) of two amino acids to form a peptide bond (red) with
expulsion of water (blue)
 BIOCHEMICAL REACTIONS
OXIDATION-REDUCTION (REDOX)
 Is type of chemical reaction that involves a transfer of electrons between two species
 Oxidation is the loss of electrons  A compound that gains electrons
from an atom is called oxidizing agent
 Reduction is the gain of electrons  A compound that loses electrons
by an atom is called reducing agent

Zn – Reducing agent
Cu – Oxidizing agent

Zn – Oxidation reaction
Cu – Reduction reaction

Zn – Lose 2 electrons
Cu – Gain 2 electrons
 BIOCHEMICAL REACTIONS
OXIDATION-REDUCTION (REDOX)
 Is type of chemical reaction that involves a transfer of electrons between two species
 Oxidation is the loss of electrons  A compound that gains electrons
from an atom is called oxidizing agent
 Reduction is the gain of electrons  A compound that loses electrons
by an atom is called reducing agent

Reduction (Gain 2 electrons)

Fe – Reducing agent
Cu – Oxidizing agent
Fe + Cu2+ Fe2+ + Cu
Fe – Oxidation reaction
Cu – Reduction reaction

Fe – Lose 2 electrons
Oxidation (Lose 2 electrons) Cu – Gain 2 electrons