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We have indeed created man in the best shape(Holy Quran)
Lecture # 1 BiochemistryFoundation Module
November-2010
Aims of Medical Sciences
To obtain the Knowledge of:Normal pattern of life.Abnormalities of life (Diseases).Procedures to prevent Diseases.Procedures to treat Diseases.
What life means to a Biologist?A variety of thoughts about life.Criteria of life:
Definite capability to grow.Increase in size.Increase in weight.
Reproduction.
Cells are made up of Specific Chemical
Compounds
Different components of cells such as
cytoplasm, nucleus, and cell membrane
are made up of specific chemical
compounds
An uncountable variety ofchemical compounds are related to
life, e.g., Bacteria may containover 5000 varieties.
Familiar examples in human body:Proteins (Haemoglobin, Collagen, Keratin, Albumin etc.). Carbohydrates (Glucose, Ribose, Chondrotin, Heparin etc.)Nucleic acids.Lipids.
Growth and Reproduction are based on Chemical Compounds and Reactions Chemical Compounds:
Proportional arrangement of specific chemical compounds.
Chemical Reactions:Synthesis of necessary compounds.Production of necessary energy.
Biological Concept of LifeLife is a biologic phenomena in which:
Certain specific chemical compounds are present in a definite proportion and in a planned manner.Still further hundreds of planned reactions are involved in growth and reproduction.
Basis of Health - Disease - Death
HEALTHSo long the chemical reactions are not
disturbed system remains healthy.DISEASE
Alterations within certain limit doesn’t kill the system but make it abnormal
(disease).DEATH
Changes beyond a limit ceases whole process and the system is dead.
Aim of studying Biochemistry?Understanding the normal pattern of life:
To get a sound knowledge of chemical compounds and reactions related to life.
Understanding the diseases:To know what, when, how & why abnormal changes takes place (Environmental, Nutritional, Genetic).
Diagnose & Treatment of diseases:To know how these changes can be prevented & corrected.
Hundreds of plannedchemical reactions
are involved in life process
Oxidation of compounds to generate energy e.g., Glucose, Fats etc.Synthesis of compounds necessary for
life e.g., Proteins, Nucleic Acids Hormones, Cholesterol etc.
A Chemical Reaction Taking Place
In Living Cell is CalledMetabolic Reaction.
Two types of metabolic reactions On the basis of final outcome:Anabolic Reactions.Catabolic Reactions.
Anabolic Reactions build up the tissues
Synthesis of higher and complex biological compounds from smaller molecules e.g., synthesis of proteins from Amino acids.Result in synthesis of complex
molecules and build up of tissues.Energy consuming reactions. Dominant during growth and
development period.
Catabolic Reactions generate energyBreakdown of higher and complex
biological compounds to simple smaller molecules e.g., Oxidation of Glucose to Water and Carbon dioxide.Energy generation during catabolism of
nutrients (Glucose, Fats etc.).Dominant during chronic debilitating
disease (TB, Cancer etc.) and old age.
In a living cell both Anabolic and Catabolic reactions take place
simultaneously according to the requirements and demands
A particular setup of metabolic reactions in a cell is called the Metabolism of the cell.
Anabolic reactions are collectively called Anabolism.Catabolic reactions are collectively called Catabolism.
During life time balance ofAnabolism and Catabolism
shifts according to circumstancesGrowing age:
Anabolism is dominant.Adulthood:
Anabolism and Catabolismrun parallel and remains balanced.
Old age and prolonged diseases:Catabolism is dominant.
Energy is fundamentalrequirement of living systems
Chemical energyFor synthetic reactions.
Mechanical energyFor contraction of muscles.
Heat energyFor maintenance of temperature.
Energy can be produced by actual burning of organic substances in air
(Oxidation or Combustion).
Such energy is not suitable for living systems because:
Can not be controlled.Can not be stored.Requires drastic conditions.
In living system energy is generated by precise chemical methods
Energy produced by such chemical methods:
Is Precisely controlled and regulated according to requirements.
Can be stored for use at a proper time.
Do not require drastic conditions of Temperature, Pressure and pH.
Bioenergetics(Biochemical thermodynamics)
Study of the energy changes accompanying biochemical reactions. Study of generation, storage and
utilization of energy in living system.
Sources of Energy In Human cellsFree or useful energy is released
during catabolic reactions:Oxidation of energy-rich organic compounds (Cellular respiration):
GlucoseFats (Glycerol & Fatty acids).Amino acids.
Storage of energy in living systemFree or useful energy is released
during catabolic reactions.This energy is captured and stored as
high energy phosphate bonds.Compounds having high energy bonds
are called high-energy compounds.
Adenosine Triphosphate (ATP)is the most commonly usedEnergy Storing Molecule
Adenine|Ribose_______P
Adenosine Monophosphate
~ P ~ P
High Energy Phosphate Bonds
Capture of Energy as ATP
Adenine|Ribose_______P ~ P ~ PEnergy generated by oxidation of food
stuffs is utilized for the formation of High- energy phosphate bonds.
ADP is converted to ATP
Release of energy by ATP
Adenine|Ribose_______P ~ P ~ P
Hydrolysis of terminal Generates 7300 Calories.ATP is Converted to ADP
Release of energy by ATPPhosphate bond splits to release free
energy Approximately 7300 cal/mol. for each of two terminal phosphate groups.Adenosine diphosphate (ADP) and
Adenosine monophosphate (AMP) are formed respectively.Phosphate bond of AMP is a low-
energy bond.
Release of energy by ATP
Adenine|Ribose_______P ~ P + Pi
Energy generated is utilized for:1. Metabolic Reactions.2. Muscle Contraction.3. Heat.
Catabolism of Nutrients
CO2 + H2O
Energy
Adenine|Ribose__P
Adenosine Monophosphate
Adenine|Ribose__P __P
Adenosine Diphosphate
Adenine|Ribose__P __P __P
Adenosine Triphosphate
An Overview of Energy Storage
Organic molecules (Nutrients Such as Glucose & Fats) contain energy, stored
in their molecular structure
Breakdown (Catabolism) of these molecules generate the energy to
synthesize High energy Phosphate bonds (ATP)
Generation and utilization of energyin human tissues is an important
concern in medical science Medical problems due to energy imbalance:
StarvationUnavailability of Energy
ObesityExcess Storage of Energy
MarasmusEnergy imbalance due to Malnutrition
Hormonal DisordersDiabetes mellitus, Diseases of Thyroid
Cellular Respiration is theMain Source of Energy
The overall process of energy generation by breakdown of food is called Cellular Respiration.The process by which the chemical
energy of food molecules (Carbohydrates, Fats, and Proteins) is released and captured in the form of ATP.
ATP / ADP Cycle
Adenine |Ribose — P ~ ~ ATP
Adenine |Ribose — P ~ ADP
7300 cal/mol
ATP as energy currency-----------------------
ATP acts as currencyof energy, when energy
is gained from high-energymolecules, is stored in
this form and it pays it to low-energy molecules,
when required.