Biochemistry

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Biochemistry

• Chapter 1
• What is Biochemistry and How Does it Relate to
  Other Areas

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Biochemistry

• Defined as the science concerned with the
  chemical basis of life
• Expanded definition The science concerned with
  the chemical constituents of living cells and
  with the reactions and processes they undergo

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• Biochemistry is the common thread that links all
  life sciences
• The book does a good job of linking Biochemistry
  with Biology, Molecular Biology, Cell biology,
  physics, and chemistry
• The relationship between Biochemistry and
  Medicine has also stimulated mutual advances

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• The World Health Organization (WHO) defines
  health as a state of Complete physical, mental,
  and social well-being and not merely the absence
  of disease and infirmity
• From a biochemical view, health may be considered
  that situation in which all of the many thousands
  of intra- and extra-cellular reactions that occur
  in the body are proceeding at rates commensurate
  with the organisms maximal survival in the
  physiological state

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• We believe that most, if not all, diseases are
  manifestations of abnormalities of molecules,
  chemical reactions, or biochemical processes.
• As a matter of fact, the major factors for
  causing diseases in animals and humans fall into
  one or more of eight categories.

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• Physical agents
• Mechanical trauma, extremes of temperature,
  sudden changes in atmospheric pressure,
  radiation, electric shock
• Chemical agents
• Drugs, toxins, therapeutic drugs, etc
• Biological agents
• Viruses, bacteria, fungi, higher forms of
  parasites
• Oxygen lack
• Loss of blood supply, depletion of the
  oxygen-carrying capacity of the blood, poisoning
  of the oxidative enzymes

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• Genetic Disorders
• Congenital, molecular
• Immunologic reactions
• Anaphylaxis, autoimmune disease
• Nutritional Imbalances
• Deficiencies, excesses
• Endocrine imbalances
• Hormonal deficiencies, excesses

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Uses of Biochemical investigations and laboratory
tests in relation to diseases

• To reveal the fundamental causes and mechanisms
  of diseases
• Demonstration of the nature of the genetic
  defects in cystic fibrosis
• To suggest rational treatments of diseases based
  on (1) above.
• A diet low in phenylalanine for treatment of
  phenylketonuria
• To assist in the diagnosis of specific diseases
• Use of the plasma enzyme creatine kinase MB
  (CK-MB) in the diagnosis of myocardial infarctions

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• 4) To act as screening tests for the early
  diagnosis of certain diseases
• Use of measurement of blood thyroxine or
  thyroid-stimulating hormone (TSH) in the neonatal
  diagnosis of congenital hypothyroidism
• 5) To assist in monitoring the progress of
  certain diseases
• Use of the plasma enzyme alanine aminotransferase
  (ALT) in monitoring the progress of infectious
  hepatitis
• 6) To assist in assessing the response of
  diseases to therapy
• Use of measurement of blood carcinoembryonic
  antigen (CEA) in certain patients who have been
  treated for cancer of the colon

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Three Principal Areas of Biochemistry

• Structural Chemistry
• Metabolism
• Molecular Genetics

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The Chemical Elements of Living Matter

• Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus