The course objectives are to provide students with an understanding of basic biochemistry concepts including biomolecules, enzymes, and nucleic acids. Biochemistry is important for learning about biological processes in cells and organisms, studying biological molecules, and developing new products through gene therapy or substituting biomolecules. It can also be used to evaluate nutrition, develop new plant varieties, process foods, study disease resistance, and formulate diets. Water is an excellent solvent and is important for biological functions due to its properties like hydrogen bonding and as a nucleophile in hydrolysis reactions. The pH scale represents the concentration of hydrogen ions, with acidic solutions having more H+ ions and basic solutions having more OH- ions. Buffers resist pH changes

1. Course objectives of unit-1 and 2
The course objectives are to provide students with a
understanding of
1. Basic concepts of Biochemistry
2. Importance of biomolecules
3. Classification of carbohydrate, lipids , amino acids and
proteins
4. Enzymes and their mechanism of action
5. Nucleic acid

2. Importance of Biochemistry
 Biochemistry described as the science concerned with the
chemical constituents of living cells and with the
reactions and processes they undergo.
 By this definition, biochemistry encompasses large areas
of cell biology, of molecular biology, and of molecular
genetics.

3.  Biochemistry is used to learn about the biological
processes which take place in cells and organisms.
 Biochemistry may be used to study the properties of
biological molecules, for a variety of purposes.
 Alternatively, a biochemist might find a substitute for a
usual biomolecule.
 Biochemists can help cells to produce new products.
Gene therapy is within the realm of biochemistry.

4.  To evaluate nutritive value of cereals, pulses, poultry and
cattle feed.
 Development and exploitation of better genotypes.
 Removal and inactivation of toxic or anti nutritional factors
present in food grains in general and grain legumes in
particular by breeding and chemical treatments.
 Food preservation and processing technology and post-
harvest physiology of fruit crops and vegetables and their
nutritional quality

5.  Biochemistry of disease and pest resistance.
 Biochemistry of drought resistance, proline and hydroxyproline
• imparts drought resistance to Jowar.
 Formulation of balanced diet.
 Use of nonconventional sources of protein foods viz., single cell
• proteins, fish protein concentrates, mushrooms and leaf proteins.
 Developments in the field of inter mediatory metabolism i.e.
• synthesis and degradation of constituents of living tissues.

6. Properties of water
 Water - one of the most important molecules in life.
 70% of the bodies mass is water.
 2/3 of total body water is intracellular (55-66% body weight of men and 10% less
for women).
 Water is an excellent solvent
 Water has high boiling point and high heat of vaporization
 Water has a high surface tension
 Water expands on freezing
 Water has high specific heat
 Ionization

7. Dipole: Due to the bent
geometry, the overall
molecule has a dipole.
Its strong dipole and high
dielectric constant enable
water to dissolve large
quantities of charged
compounds

8. • Hydrogen bonding: H bonding enables
water to dissolve many organic
biomolecules that contain functional
groups which can participate in hydrogen
bonding
• Water is an excellent nucleophile:
Nucleophilic attack by water generally
results in the cleavage of the amide,
glycoside, or ester bonds that hold
biopolymers together. This process is
termed hydrolysis.
• Conversely, when monomer units are
joined together to form biopolymers such
as proteins or glycogen, water is a product,

9. pH
• The term pH was introduced in 1909 by Sörensen
• pH is defined as the negative logarithm (base 10) of the
H+ ion concentration.
• pH = -log [H+]
• -pH = log[H+]
• 10 -pH = [H+]
• What is the pH of a neutral solution at 25°?
• Under this condition, the concentration of hydrogen ion
is 1.0 x 10-7M
• pH = -log(1.0 x 10-7) = -(-7.0) = 7.0
• Low pH values correspond to high concentrations of H+
and high pH values correspond to low concentrations of
H+.

10. Example

11. What is the pH of an acidic solution?
• An acidic solution is one where we have an increase in [H+]
• If a neutral solution has a [H+] of 1 x 10-7M, then an acidic
solution must have a [H+] that is greater than 1 x 10-7M
• For example, a solution with a [H+] = 1 x 10-6M will be
acidic.

12. What is the pH of a basic solution?
• A basic solution is one in which
the [OH-] is greater than 1 x 10-7M
• For example, a solution has a [OH-] =
1.0 x 10-5M (this is greater than 1 x
10-7M, and so this solution is basic)
• Basic solutions will have increasingly
higher values of pH (i.e. pH 12 would
be a potent base)

13. The Henderson-Hasselbalch Equation: Describes the
Behavior of Weak Acids & Buffers

15. Buffers
• Buffers are solutions that resist changes in pH as acid and base are added
Composition of Buffers
• To effectively maintain a pH range, a buffer must consist of a weak conjugate acid-
base pair, meaning either
• a weak acid and its conjugate base,
• a weak base and its conjugate acid.
• The use of one or the other will simply depend upon the desired pH when preparing
the buffer. For example, the following could function as buffers when together in
solution:
• Acetic acid (weak organic acid w/ formula CH3COOH) and a salt containing its
conjugate base, the acetate anion (CH3COO-), such as sodium acetate (CH3COONa)
• Pyridine (weak base w/ formula C5H5N) and a salt containing its conjugate acid, the
pyridinium cation (C5H5NH+), such as Pyridinium Chloride.
• Ammonia (weak base w/ formula NH3) and a salt containing its conjugate acid, the
ammonium cation, such as Ammonium Hydroxide (NH4OH)
• Most buffers consist of a weak acid and its conjugate base

16. Biological Buffer Systems
• The phosphate buffer systems
• The bicarbonate buffer systems
• The protein buffer systems
• The amino acids buffer systems
• The Hemoglobin buffer systems