Concise biochemistry Lecture for nurses.

Biochemistry for Nurses pdf

1. Biochemistry Lecture
1
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2. What is Biochemistry
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Biochemistry can be defined as the science of the
chemical basis of life (The cell is the structural unit of
living systems).
Thus, biochemistry can also be described as the science
of the chemical constituents of living cells, the reactions
and processes they undergo
Is the branch of science dedicated to the study of these
chemical processes within a cell.

3. •Understanding these processes can also lend insight into disease states and the
pharmacological effects of toxins, drugs and other medicines within the body
•Medical Biochemistry focuses on aspects of biochemistry relevant to medicine:
on explaining how the body works as a chemical system and how it
malfunctions during illness.
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4. •Biochemistry provides insight into nutrition and exercise, and metabolic
stress, it contributes to understanding how diet and lifestyle influence our
health and performance, as well as how the organism ages.
•It describes how cellular communications systems respond to endogenous and
environmental stress.
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5. Aim of Biochemistry
•The major objective of biochemistry is the complete understanding, at the
molecular level, of all of the chemical processes associated with living cells.
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6. Relationship Between Biochemistry & Medicine
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The two major
concerns for
health workers
are the
understanding
the
maintenance of
health and the
understanding
the effective
treatment of
diseases.
Biochemistry
impacts
enormously
on both of
these
fundamental
concerns of
medicine.
Eg. knowledge of
protein structure
and function was
necessary to
understand the
biochemical
difference between
normal
hemoglobin and
sickle cell
hemoglobin.

7. •On the other hand, analysis of sickle cell hemoglobin has contributed
significantly to our understanding of the structure and function of both normal
hemoglobin and other proteins
•Biochemistry also provides a foundation for understanding the action of
medicines, such as antidepressants, drugs used to treat diabetes, hypertension
and heart failure, and those that lower blood lipids.
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8. Why study Biochemistry
•One studies biochemistry to understand the interplay of
nutrition, metabolism and genetics in health and disease

•The human organism is, on the one hand, a tightly
controlled, integrated and self-contained metabolic system.
•
•On the other, it is a system that is open and communicates
with its environment.
•Despite these two seemingly contradictory characteristics,
the body manages to maintain its internal environment for
decades.
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9. •We regularly consume food and water and take up oxygen from inspired air to
use for oxidative metabolism.
•We then use the energy generated from metabolism to perform work and to
maintain body temperature and get rid of (exhale or excrete) carbon dioxide,
water and nitrogenous waste.
•The amount and quality of food we consume have significant impact on our
health – malnutrition on the one hand and obesity and diabetes on the other, are
currently major public health issues worldwide.
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10. •Biochemistry describes in molecular
terms the structures, mechanisms,
and chemical processes shared by all
organisms.
•It provides organizing principles that
underlie life in all its diverse forms,
principles we refer to collectively as
the molecular logic of life
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11. •The Molecular
Logic of Life
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12. Question of the Day
What distinguishes
living organisms from
inanimate objects?
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13. •Degree of chemical complexity and organization
•Living organisms extract, transform and use energy from their environment
(energy is important for structure, mechanical, chemical, osmotic and other
types of work).
• Precise self-replication and self-assembly e.g. bacterial replication
•Living organisms are enormously diverse, yet similar at the cellular and
chemical levels.
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14. The Logic
•The unity and diversity of organisms become apparent even at the cellular
level.
•The smallest organisms consist of single cells and are microscopic.
•Larger, multicellular organisms contain many different types of cells, which
vary in size, shape, and specialized function.
•Despite these obvious differences, all cells of the simplest and most complex
organisms share certain fundamental properties, which can be seen at the
biochemical level.
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15. The cell
•Cells of all kinds share certain structural features.
•a. Plasma membrane: periphery of the cell, separating its contents from the
surroundings. It is composed of lipid and protein molecules that form a thin,
tough, hydrophobic barrier around the cell.
• The membrane is a barrier to the free passage of inorganic ions and the entire
structure is flexible, allowing changes in the shape and size of the cell.
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16. The cell cont.
• As a cell grows, newly made lipid and protein molecules are inserted into its
plasma membrane; cell division occurs to produces two cells, each with its
own membrane.
•This growth and cell division (fission) occurs without loss of membrane
integrity.
•The internal volume of the cell is enclosed by the plasma membrane.
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17. •b. The cytoplasm: composed of an aqueous solution (the cytosol), and a
variety of suspended particles with specific functions.
•The cytosol is a highly concentrated solution containing; Enzymes, amino
acids and nucleotides from which these macromolecules are assembled,
ribosomes (sites of protein synthesis) and proteasomes, which degrade
proteins that are no longer needed by the cell
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18. Types of Cells
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Eukaryotes: The nucleus
consists of nuclear material
enclosed within a double
membrane, the nuclear
envelope.
Eukaryotes (Greek eu,
“true,” and karyon,
“nucleus”).
Prokaryotes: The nucleoid,
in bacteria is not separated
from the cytoplasm by a
membrane.
Microorganisms without
nuclear envelopes, are
grouped together as
prokaryotes (Greek pro,
“before”)

19. Prokaryotes
•Organisms made up of cells that lack a cell nucleus or any membrane-encased
organelles.
• Genetic material(DNA)is not bound within a nucleus, less structured and a single
loop.
•Some prokaryotes including E. coli, Salmonella, and Listeria, are found in foods
and can cause disease whiles others are helpful to human digestion and other
functions.
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20. The Prokaryotic Cell
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21. Eukaryotes
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Are organisms
made up of
cells that
possess a
membrane-
bound nucleus
(that holds
DNA in the
form of
chromosomes)
as well as
membrane-
bound
organelles.
Eukaryotic
organisms
may be
multicellular
or single-
celled
organisms.
Allanimals
are
eukaryotes.
Cell is surrounded
by a plasma
membrane and
contains many
different structures
and organelles.
Examples include
the chromosomes
(carry genetic
information in the
form of genes), and
the mitochondria
(often described as
the "powerhouse of
the cell")

22. The Eukaryotic Cell
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23. •Biomacromolecules:
composition and
principles of organization
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24. What are biomolecules
• Biomacromolecules are biomolecules which have a large size and high
molecular weights and complexstructures.
•The 4 main Biomacromolecules areProteins,Nucleic Acids (DNA and
RNA),Carbohydratesandlipids.
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25. Cell Energy Production
•The building and breaking down of life-sustaining chemicals within an
organism is known asMetabolism.
•Overall, the three main purposes of metabolism are:
•(1) the conversion of food to energy to run cellular processes;
• (2) the conversion of food/fuel to building blocks for the production
ofmetabolites, such as proteins, lipids, nucleic acids and
•(3) the elimination of waste products.
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26. •These allows organisms to grow and reproduce, maintain their structures, and
respond to their environments.
•Metabolic reactions may be categorized ascatabolic– thebreaking downof
compounds (for example, the breaking down of proteins into amino acids
during digestion);
•oranabolic– thebuilding up(synthesis) of compounds (such as proteins,
carbohydrates, lipids, and nucleic acids).
•Usually, catabolism releases energy, and anabolism consumes energy.
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27. Metabolic reactions
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28. Metabolic reactions
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29. Biomacromolecule 1 (Proteins)
•They are said to constitute the majority of biomolecules in a cell.
•Simpler units known asaminoacids make up these biological polymers.
•They are linked together bycovalent bondsknown as peptide bonds.
•There are 20 different types of amino acids.
•Proteins are responsible for many functions in the body which includes
structural proteins, enzyme proteins, transport proteins etc.
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30. •Are physically and functionally complex macromolecules that perform multiple
critically important roles.
• internal protein network, the cytoskeleton maintains cellular shape and
physical integrity and have receptors that enable cells to sense and respond to
hormones and other environment
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31. •Proteins are subject to physical and functional changes that occurs in the life
cycle of the organisms in which they reside
•An important goal of molecular medicine is the identification of proteins and
those events in their life cycle whose presence, absence, or deficiency is
associated with specific physiologic states or diseases.
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32. Biomacromolecule 2 (Carbohydrates)
•These are biomolecules which primarily contain carbon, hydrogen and oxygen.
Also known assugars.
•Carbohydratesare classified into different classes depending on the number of
monomer units present in them such as monosaccharides (single monomer
unit) e.g. glucose, fructose.
•Glucose is the energy currency of the cells in animals and fructose is in plants,
disaccharides (two monomer units), polysaccharides(multiple monomer units).
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33. •Distributed in plants and animals and have important structural and metabolic
roles.
•In plants, glucose is synthesized from carbon dioxide and water by
photosynthesis and stored as starch
•In animals, carbohydrates are synthesized to form of glucose.
•Most dietary carbohydrate is absorbed into the bloodstream as glucose formed
by hydrolysis of dietary starch and disaccharides, and other sugars are
converted to glucose in the liver
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34. •Glucose is the major metabolic fuel of mammals (except ruminants) and a
universal fuel of the fetus.
•It is the precursor for synthesis of all the other carbohydrates in the body,
including glycogen for storage; ribose and deoxyribose in nucleic acids;
galactose in lactose of milk
•Diseases associated with carbohydrate metabolism include diabetes mellitus,
galactosemia, glycogen storage diseases, and lactose intolerance
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35. Biomacromolecule 3 (Lipids)
•Lipids are similar to carbohydrates in that they are made up of carbon,
hydrogen andoxygen.
•But unlike carbohydrates, on hydrolysis, lipids yield glycerol and fatty acids
(unsaturated and saturated fatty acids).
• Lipids are also found in fats, oils, hormones and other structures such as the
cell membrane. A complex form of lipids which is stored in the body as adipose
tissue is known as triglycerides
•Lipids are said to be ‘hydrophobic’ and are not miscible in water in contrast to
the other biomacromolecules which are ‘hydrophilic
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36. They have the common property of being
• relatively insoluble in water and
• soluble in nonpolar solvents such as ether and chloroform.
•Important dietary constituents not only because of their high energy value, but
also because of the fat-soluble vitamins and the essential fatty acids contained in
the fat of natural foods.
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37. •Fat is stored in adipose tissue, where it also serves as a thermal insulator in the
subcutaneous tissues and around certain organs.
•Combinations of lipid and protein (lipoproteins) serve as the means of
transporting lipids in the blood.
•Knowledge of lipid biochemistry is necessary in understanding many
important biomedical areas, eg, obesity, diabetes mellitus, atherosclerosis, and
the role of various polyunsaturated fatty acids in nutrition and health
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38. Biomacromolecule 4 (nucleic acids)
•Smaller monomeric units that are known asnucleotidesform nucleic acids.
•Nucleic acids regulate various functions in the body such as growth,
reproduction and metabolism.
• Also, forms the genes of an individual that is responsible for heredity.
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39. •Primarily two types of nucleic acids: DNA and RNA.
•DNA or deoxyribonucleic acid consists of nucleotides made up of four
nitrogen bases namely adenine, guanine, thiamine and cytosine.
•Whereas adenine, guanine, cytosine and uracil ( in place of thiamine) make
upRNA or ribonucleic acid.
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40. •The discovery was one of the major scientific achievements of the 20th century.
• This polymeric molecule, deoxyribonucleic acid (DNA), is the chemical basis
of heredity and is organized into genes, the fundamental units of genetic
information.
•The basic information pathway ie DNA, which directs the synthesis of RNA,
which in turn both directs and regulates protein synthesis has been very
important
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41. •Knowledge of the structure and function of nucleic acids is essential in
understanding genetics and many aspects of pathophysiology as well as the
genetic basis of disease.
•Abnormalities in gene products (either in RNA, protein function, or amount)
can be the result of mutations that occur in coding or regulatory-region DNA.
•A mutation in a germ cell is transmitted to offspring (so-called vertical
transmission of hereditary disease).
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42. •Factors, such as viruses, chemicals, ultraviolet light, and ionizing radiation,
increase the rate of mutation.
• Mutations often affect somatic cells and then passed on to successive
generations of cells, but only within an organism (ie, horizontally).
•It is becoming apparent that a number of diseases and perhaps most cancers are
due to the combined effects of vertical transmission of mutations as well as
horizontal transmission of induced mutations
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43. Summary
•To be done by students
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44. •Thank you
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