Dr. Mohamed Kotb Lectures 1 Bio 1 Techno PDF

Lectures 1 Dr. Mohamed Kotb El-Sayed Professor of Pharmaceutical Biochemistry & Molecular Biology 1 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Objectives:...

Lectures 1 Dr. Mohamed Kotb El-Sayed Professor of Pharmaceutical Biochemistry & Molecular Biology 1 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Objectives: Introduction. By the end of These lectures, you should be familiar with:  1- Definition and importance of biochemistry.  2- Biochemistry and Clinical Medicine.  3- Interaction of Nutrition, Metabolism & Disease.  4- Major Structural Components of the Body.  5- Biological Membranes.  6- ATP as Energy Currency.  7- Metabolism.  8- Role of Oxygen in Metabolism.  9- Fed-Fasting Cycle and Metabolism.  10- Genome and Metabolism.  Summary. 2 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Definitions and Importance of Biochemistry. Introduction.  Biochemistry is the study and explain all chemical processes and its regulations in all living organisms.  This processes include all areas of the life sciences from botany to medicine to genetics.  The main aim of pure biochemistry is in understanding how biological molecules (CHO, Lipids & Proteins) lead to the processes that occur within living cells to, understand the study of whole organisms.  Biochemistry is closely related to molecular biology, the study of the molecular mechanisms by which genetic information encoded in DNA is result in the processes of life. 3 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Definitions and Importance of Biochemistry. Introduction.  Biochemistry deals with the structures, functions and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates and lipids, which provide the structure of cells and perform many of the functions associated with life.  The chemistry of the cell also depends on the reactions of smaller molecules and ions. These can be inorganic, for example water and metal ions, or organic, for example the amino acids which are used to synthesize proteins.  The mechanisms by which cells use energy from their environment via chemical reactions are known as metabolism. 4 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Definitions and Importance of Biochemistry. Introduction.  The outcomes of biochemistry are applied primarily in medicine, and nutrition.  In medicine, biochemists investigate the causes of disease.  In nutrition, they study how to maintain health and study the effects of nutritional deficiencies.  Much of biochemistry deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules. 5 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Biochemistry and Clinical Medicine. Introduction.  It describes clinical applications of biotechnology and genomics.  Considering nutrition, 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 signaling and communications systems respond to endogenous and environmental stress. 6 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Interaction of Nutrition, Metabolism & Disease. Introduction.  Biochemistry illustrates this interaction.  We regularly consume food, water, and take up oxygen from inspired air to use for oxidative metabolism (which is in fact a chain of low- temperature combustion reactions).  We then use the energy generated from metabolism to perform work and to maintain body temperature.  We 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. 7 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology The Major Structural Components of The body. Introduction.  Proteins are building blocks and catalysts;  as structural units, they form the ‘architectural’ framework of tissues;  as enzymes, together with helper molecules (coenzymes and cofactors), they catalyze biochemical reactions.  Lipids, such as cholesterol and phospholipids, form the backbone of biological membranes.  Carbohydrates and lipids are our major energy sources.  They can be stored in tissues as glycogen and triglycerides.  However, carbohydrates can also be linked to both proteins and lipids, essential for cell signaling systems and processes such as cell adhesion and immunity. 8 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology The Major Structural Components of The body. Introduction.  Chemical variables, such as pH, oxygen tension, and inorganic ion and buffer concentrations, define the homeostatic environment in which metabolism takes place. ▪ Minute changes in this environment, for example, less than a fifth of a pH unit or just a few degrees' change in body temperature, can be life- threatening.  The blood is a unique transport medium that participates in the exchange of gases, fuels, metabolites – and information – between tissues. ▪ Moreover, the plasma, which can be easily sampled and analyzed, is a ‘window’ on metabolism and a rich source of clinical information. 9 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Biological Membranes. Introduction.  It is formed from phospholipids bilayer, impermeable to polar molecules.  It is partition metabolic pathways into different cellular compartments.  These membranes are gated with an array of ‘doors and gates’ (membrane transporters) and ‘locks’ that accept to opened by keys (hormone, cytokine and other receptors) and generate intracellular signals.  They play a fundamental role in transport, and in signal transduction both from one cell to another, and within individual cells.  Cells throughout the body are critically dependent on membrane potentials for nerve transmission, muscle contraction, nutrient transport and the maintenance of cell volume. 10 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology ATP (Energy Currency). Introduction. Energy released from nutrients is distributed in the form of adenosine triphosphate (ATP):  Energy capture in biological systems occurs through oxidative phosphorylation which takes place in the mitochondrion.  This process involves oxygen consumption, or respiration, by which the organism uses the energy of fuels to produce a hydrogen ion gradient across the mitochondrial membrane and capture this energy as adenosine triphosphate (ATP).  Biochemists call ATP the ‘common currency of metabolism’ because it allows energy from fuel metabolism to be used for work, transport and biosynthesis. 11 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Metabolism. Introduction. Metabolism is a network of chemical processes:  Carbohydrates and lipids are our primary sources of energy, but our nutritional requirements also include amino acids (components of proteins), inorganic molecules containing sodium potassium phosphate and other atoms, and micronutrients – vitamins and trace elements.  Glucose is metabolized through glycolysis, a universal non-oxygen requiring (anaerobic) pathway for energy production.  Glycolysis yields pyruvate, setting the stage for oxidative metabolism in the mitochondria (Krebs cycle). 12 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Metabolism. Introduction. Metabolism is a network of chemical processes:  Glycolysis also generates metabolites that are the starting points for synthesis of amino acids, proteins, lipids and nucleic acids.  Glucose is the most important fuel for the brain: therefore, maintaining its concentration in plasma is essential for survival.  Glucose supply is linked to the metabolism of glycogen, its short-term storage form.  Glucose homeostasis is regulated by the hormones that coordinate metabolic activities among cells and organs – primarily insulin in addition to glucagon, epinephrine and cortisol. 13 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Role of Oxygen in Metabolism: Introduction. Oxygen is essential for energy production but can also be toxic:  During aerobic metabolism, pyruvate is transformed into acetyl-CoA, the common intermediate in the metabolism of carbohydrates, lipids and amino acids.  Acetyl-CoA enters the central metabolic engine of the cell, the tricarboxylic acid cycle (TCA cycle) located in the mitochondria.  Acetyl-CoA is oxidized to carbon dioxide and reduces the important coenzymes nicotinamide adenine dinucleotide (NAD+) and flavin adenine dinucleotide (FAD).  Reduction of these nucleotides captures the energy from fuel oxidation. 14 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Role of Oxygen in Metabolism: Introduction. Oxygen is essential for energy production but can also be toxic:  They in turn become substrates for the final pathway, oxidative phosphorylation, where the electrons they carried reduce molecular oxygen through a chain of electron transport reactions, providing the energy for the synthesis of ATP.  While oxygen is essential for metabolism, it can also cause oxidative stress and widespread tissue damage during inflammation.  Powerful antioxidant defenses exist to protect cells and tissues from damaging effects of oxygen. 15 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Fed and Fasting Cycle: Introduction. Metabolism continuously cycles between fasting and post- eating modes  The direction of the main pathways of carbohydrate and lipid metabolism changes in response to food intake.  In the fed state, the active pathways are glycolysis, glycogen synthesis, lipogenesis and protein synthesis, storing the excess of metabolic fuel.  In the fasting state, the direction of metabolism reverses: glycogen and lipid stores are degraded through glycogenolysis and lipolysis, providing a constant stream of substrates for energy production. 16 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Fed and Fasting Cycle: Introduction. Metabolism continuously cycles between fasting and post- eating modes  As glycogen stores became depleted, proteins are sacrificed to make glucose through gluconeogenesis, guaranteeing a constant supply, while other biosynthetic pathways are slowed down.  Common conditions such as diabetes mellitus, obesity and atherosclerosis that are currently major public health issues, result from impairment of fuel metabolism and transport. 17 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology The Genome Supports It All: Introduction.  The genome provides the mechanism for conservation and transfer of genetic information, through gene expression and their control of protein synthesis.  The synthesis of individual proteins is controlled by information encoded in DNA and transcribed into RNA, which is then translated into peptides that fold into functional protein molecules.  Further, applications of recombinant DNA technology have revolution in the work of clinical laboratories, and industrial biotechnology. 18 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Summary. Introduction. 19 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology Reference CELL MEMB. http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=mcb.TOC [email protected] WhatsApp: 00201114871491 https://www.researchgate.net/profile/Mohamed_kotb_Kotb-El-Sayed2 20 Dr. Mohamed I. Kotb – Professor of Pharmaceutical Biochemistry and Molecular Biology