.
Don’t fall behind..
• If you read what I am teaching today, you need just 30 mins
to revise the topic and solve mcqs.
• If you don’t read for three days ….you will need 2 days to
cover a topic and BY THEN I’ll have finished another 2
topics already…..
• Biochemistry is a LOT OF UNDERSTANDING AND A LOT OF
MEMORIZATION too…..
WHY ? Any chemistry is VOLATILE …revision is the KEY
BOOKS for MD2
• Lippincott or Harper ( good for metabolism!)
• Kaplan Step 1 Lecture notes :- Mol .Biology
and Genetics
• MCQs- good sources
– PRE-TEST BIOCHEMISTRY AND GENETICS
– BRS QUESTION BANK
– USMLE WORLD Q.BANK
– KAPLAN Q.BANK
BASIC RULES
• Switch off MOBILES
• Don’t come late
– You’ll be not be allowed to enter after 5 minutes.
• No edibles
• No blowing/bubbling of chewing gums
INTERNAL ASSESSMENT
• FINAL DISTRIBUTION
– (30% BLOCK 1) + (30% BLOCK 1)+ (30% NBME )+ 10 %
internal assessment
INTERNAL ASSESSMENT means :(10% block 1 + 10 % block 2 + 10% class performance)
Class performance ( 10%)
– 30% CLASS QUIZZES
– 20% CLASS ASSIGNMENTS
– 50% SMALL GROUP & CLINICAL CASE DISCUSSION
PERFORMANCE
.
BIO ( Greek, from bios)
+
CHEMISTRY
Need an official definition ??
Life :- The condition that distinguishes animals
and plants from inorganic objects and dead
organisms, being manifested by growth
through metabolism, reproduction, and the
power of adaptation to environment through
changes originating internally.
ENERGY,
(1)
which it must
know how to:
•
Extract
•
Transform
•
Utilize
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Digestion
and Oxidation of food
Reducing
equivalents
B
I
O
L
O
G
I
C
A
L
O
X
I
D
A
T
I
O
N
ATP
ENERGY !!
ATP is the energy currency of the cell!
Life needs …
(2)
SIMPLE MOLECULES,
which it must know how to:
• Convert
• Polymerize
• Degrade
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Macromolecules
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Macromolecules
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Biomolecules – Structure
• Building block
•
Anabolic pathways
Macromolecule
Simple sugar
Amino acid
Nucleotide
Fatty acid
•
•
•
•
Polysaccharide
Protein (peptide)
RNA or DNA
Lipid
•
•
•
•
Catabolic
Pathways
23
How did organic complex molecules evolved from
more simple molecules?
•Urea was synthesized by heating the inorganic compound
ammonium cyanate (1828)
•This showed that compounds found exclusively in living organisms
could be synthesized from common inorganic substances
24
The Urey-Miller experiment (1950)
Some amino acids could be produced:
25
Why is potassium concentration more
inside a cell than outside ?
Life needs …
(3)
CHEMICAL MECHANISMS, to:
• Harness energy
•
•
•
•
•
•
Drive sequential chemical reactions
Synthesize & degrade macromolecules
Maintain a dynamic steady state
Self-assemble complex structures
Replicate accurately & efficiently
Maintain biochemical “order” vs outside
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THE METABOLIC REACTIONS
ARE SIMILAR
IN ALL LIFE FORMS………
• ANATOMY :- ( Greek ἀνατομία anatomia,
from ἀνατέμνειν ana: separate, apart from,
and temnein, to cut up, cut open) is a branch
of biology and medicine that is the
consideration of the structure of living things.
• PHYSIOLOGY:- The science of the function of
living systems showing how organisms, organ
systems and organs carry out the chemical or
physical functions that exist in a living system.
• Biochemistry can also be described as the
science of the chemical constituents of living
cells and of the reactions and processes they
undergo.
• The Aim of Biochemistry Is to Describe &
Explain, in Molecular Terms, All Chemical
Processes of Living Cells.
•MOLECULAR BIOLOGY
•MOLECULAR DIAGNOSTICS
•IMMUNOCHEMISTRY
•NEUROCHEMISTRY
•BIOINORGANIC, BIOORGANIC, AND
BIOPHYSICAL CHEMISTRY.
•LABORATORY DIAGNOSIS
•THERAPY – ALMOST EVERYWHERE
Biochemical Research Has Impact on Nutrition &
Preventive Medicine.
– One major prerequisite for the maintenance of health
is that there be optimal dietary intake of a number of
chemicals;
•
•
•
•
•
vitamins,
certain amino acids,
certain fatty acids,
various minerals,
and water.
– Preventive medicine largely focuses on providing
these in adequate amounts.
The Major Causes of Diseases
1. Physical agents: Mechanical trauma, extremes of temperature, sudden changes in
atmospheric pressure, radiation, electric shock.
2. Chemical agents, including drugs: Certain toxic compounds, therapeutic drugs, etc.
3. Biologic agents: Viruses, bacteria, fungi, higher forms of parasites.
4. Oxygen lack: Loss of blood supply, depletion of the oxygen-carrying capacity of the
blood, poisoning of the oxidative enzymes.
5. Genetic disorders: Congenital, molecular.
6. Immunologic reactions: Anaphylaxis, autoimmune disease.
7. Nutritional imbalances: Deficiencies, excesses.
8. Endocrine imbalances: Hormonal deficiencies, excesses.
Some Uses of Biochemical Investigations and Laboratory Tests in
Relation to Diseases
Use
1. To reveal the fundamental causes and
mechanisms of diseases
2. To suggest rational treatments of diseases
based on item 1 above
3. To assist in the diagnosis of specific diseases
Example
Demonstration of the nature of the genetic
defects in Phenylketonuria.
A diet low in phenylalanine for treatment of
phenylketonuria.
Use of the plasma levels of troponin I or T in
the diagnosis of myocardial infarction.
4. To act as screening tests for the early
Use of measurement of blood thyroxine or
diagnosis of certain diseases
thyroid-stimulating hormone (TSH) in the
neonatal diagnosis of congenital
hypothyroidism.
5. To assist in monitoring the progress (ie,
Use of the plasma enzyme alanine
recovery, worsening, remission, or relapse) of aminotransferase (ALT) in monitoring the
certain diseases
progress of infectious hepatitis.
6. To assist in assessing the response of
Use of measurement of blood
diseases to therapy
carcinoembryonic antigen (CEA) in certain
patients who have been treated for cancer of
the colon.
• ALL DRUGS ARE MOSTLY COMPETETIVE
INHIBITORS OF MANY BODY ENZYMES .
• MOST TOXINS ARE NON –COMPETETIVE
INHIBITORS OF THE BODY ENZYMES.
• Completed in 2003, the Human Genome Project
(HGP) was a 13-year project coordinated by the
U.S. Department of Energy and the National
Institutes of Health.
Is it enough?
PROTEOMICS !!
1. Average no of genes is 40,000- 60, 000, average no .
of proteins is more than ½ a million in humans.
2. Average no of proteins per gene -one to two in bacteria,
three in yeast
three to six per gene ,in human beings .
3. In addition to genetic makeup , many other factors
determine proteins behavior and expression- factors
like pH, oxygen depletion , chemicals and drugs etc.
THE ‘OMICS
•
•
•
•
•
•
•
•
GENOMICS
TRANSCRIPTOMICS
PROTEOMICS
METABOLOMICS
GLYCOMICS
LIPIDOMICS
NUTRIGENOMICS
PHARMACOGENOMICS
…..and of course BIOINFORMATICS!!