Concise biochemistry Lecture for nurses.
- 2. What is Biochemistry 9/22/2024 2 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. 9/22/2024 3
- 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. 9/22/2024 4
- 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. 9/22/2024 5
- 6. Relationship Between Biochemistry & Medicine 9/22/2024 6 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. 9/22/2024 7
- 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. 9/22/2024 8
- 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. 9/22/2024 9
- 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 9/22/2024 10
- 11. •The Molecular Logic of Life 9/22/2024 11
- 12. Question of the Day What distinguishes living organisms from inanimate objects? 9/22/2024 12
- 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. 9/22/2024 13
- 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. 9/22/2024 14
- 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. 9/22/2024 15
- 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. 9/22/2024 16
- 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 9/22/2024 17
- 18. Types of Cells 9/22/2024 18 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. 9/22/2024 19
- 21. Eukaryotes 9/22/2024 21 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. All animals 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")
- 23. •Biomacromolecules: composition and principles of organization 9/22/2024 23
- 24. What are biomolecules • Biomacromolecules are biomolecules which have a large size and high molecular weights and complex structures. • The 4 main Biomacromolecules are Proteins, Nucleic Acids (DNA and RNA), Carbohydrates and lipids. 9/22/2024 24
- 25. Cell Energy Production • The building and breaking down of life-sustaining chemicals within an organism is known as Metabolism. • 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 of metabolites, such as proteins, lipids, nucleic acids and • (3) the elimination of waste products. 9/22/2024 25
- 26. • These allows organisms to grow and reproduce, maintain their structures, and respond to their environments. • Metabolic reactions may be categorized as catabolic– the breaking down of compounds (for example, the breaking down of proteins into amino acids during digestion); • or anabolic – the building up (synthesis) of compounds (such as proteins, carbohydrates, lipids, and nucleic acids). • Usually, catabolism releases energy, and anabolism consumes energy. 9/22/2024 26
- 29. Biomacromolecule 1 (Proteins) • They are said to constitute the majority of biomolecules in a cell. • Simpler units known as amino acids make up these biological polymers. • They are linked together by covalent bonds known 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. 9/22/2024 29
- 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 9/22/2024 30
- 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. 9/22/2024 31
- 32. Biomacromolecule 2 (Carbohydrates) • These are biomolecules which primarily contain carbon, hydrogen and oxygen. Also known as sugars. • Carbohydrates are 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). 9/22/2024 32
- 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 9/22/2024 33
- 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 9/22/2024 34
- 35. Biomacromolecule 3 (Lipids) • Lipids are similar to carbohydrates in that they are made up of carbon, hydrogen and oxygen. • 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 9/22/2024 35
- 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. 9/22/2024 36
- 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 9/22/2024 37
- 38. Biomacromolecule 4 (nucleic acids) • Smaller monomeric units that are known as nucleotides form 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. 9/22/2024 38
- 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 up RNA or ribonucleic acid. 9/22/2024 39
- 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 9/22/2024 40
- 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). 9/22/2024 41
- 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 9/22/2024 42
- 43. Summary •To be done by students 9/22/2024 43