Introduction to Biochemistry & Protein Chemistry PDF

Field of Medicine Medicine And Surgery Program Lecture : Introduction Dr : Moataz maher Date : / / Introduction to Medical Biochemistry & Protein Chemistry What’s your expectations from studying Biochemistry & Molecular Biology Objectives: By the end of this lecture the student wi...

Field of Medicine Medicine And Surgery Program Lecture : Introduction Dr : Moataz maher Date : / / Introduction to Medical Biochemistry & Protein Chemistry What’s your expectations from studying Biochemistry & Molecular Biology Objectives: By the end of this lecture the student will be able to: 1. Identify the importance of Biochemistry in Medicine. 2. Recognize the major biomolecules in living organisms. 3. Recognize the types of living cells and cell compartments. 4. Describe the chemical structure of proteins.  1. What is Biochemistry? Biochemistry = chemistry of life. Living organisms contain thousands of molecules (simple & complex). These molecules are complicated and highly organized (proteins, DNA, RNA, carbohydrates, and lipids) Biochemistry is the study of these biomolecules function, interaction, synthesis and degradation inside the living cell. Living organisms can a. extract b. Store ENERGY c. Use  Principle Areas of Biochemistry Structure and function of biological macromolecules Metabolism – Anabolic and catabolic processes. Molecular Biology – How life is replicated? – How protein synthesis is regulated?  Role of Biochemistry in Medicine Several diseases have a molecular basis, so Biochemistry enables us to Understand the chemical processes involved in such conditions. Diagnosis and follow up of diseases. It is a guide to discovery of therapy and apply it to diseases. In nutrition: The nutrients value of food material can also be determined by biochemical tests. For maintenance of health, optimum intake of many chemicals like vitamins, minerals, essential fatty acids is needed  Nutritional imbalance leads to disease.  2. Biomolecules The human body is composed of: - Major elements (C, H, N, O, P, S). These elements are major components of important biomolecules, such as proteins, nucleic acids, polysaccharides and lipids. - Less abundant: Na, Mg, K, Ca, Cl - Trace elements: Mn, Fe, Co, Cu, Zn. The major components of the body are water (60%). The others include proteins (17%), fat (14%), carbohydrates (1.5%) and minerals (6%).  2. Biomolecules - Large biomolecules are polymers (Greek: poly + meros, many + parts) - They are derived from monomers (Greek: mono + meros, single + part)  What are the different types of cells? Extract differences between these cells  3. Types of Cells The cell is the fundamental unit of biologic activity. Living cells fall into 2 broad categories: - Prokaryotes - Eukaryotes In Greek “before the nucleus” In Greek “true nucleus” a. Single-celled organisms (such as a. contains a well-defined nucleus bacteria) surrounded by a nuclear b. It lacks nuclei and other membrane organelles b. can be single celled, such as c. It has only one membrane yeasts, or multicellular, such as “Plasma membrane” animals and plants  Prokaryote Cell Simplest No organelles No nucleus No membrane bound organelles DNA uncomplexed by histones  Eukaryote Cell More complex – Contain organelles – Has a nucleus More DNA – Has to be folded – Contains histones  Differences between Prokaryotes & Eukaryotes Organelle Prokaryotes Eukaryotes Nucleus No definite nucleus; DNA Present present but not separated from the rest of the cell Cell membrane Present Present Mitochondria None: enzymes for oxidation Present are on plasma membrane Endoplasmic None Present reticulum Ribosomes Present Present  Summary of Cell Organelles of and Their Functions Organelle Function Nucleus Location of main genome; site of most DNA and RNA synthesis Mitochondria Site of energy-production reactions; has its own DNA Endoplasmic Rough: synthesis, folding and reticulum modification of proteins. Smooth: synthesis of phospholipids and cholesterol.  Cell organelles and their functions (cont.) Golgi Cell post office. apparatus Involved in secretion of proteins to their cellular target Lysosomes contain hydrolytic enzymes responsible for breakdown of different molecules Peroxisomes Breaks down H2O2 and other products that can damage the cell components Cell membrane Separates the cell contents from the outside world Where can we find proteins?  4. Chemical structure of proteins Proteins are the most abundant macromolecules in living cells. All proteins contain the elements carbon (C), hydrogen (H), oxygen (O) and nitrogen (N). Most proteins contain about 1% of the element sulfur Certain specialized proteins contain other elements such as phosphorus (found in milk).  Amino Acids (The structural unit of proteins)  Amino acids are the building block of proteins.  All proteins are made of a long chain of amino acids linked together by peptide bonds and other bonds forming a polypeptide chain.  All proteins are made up of one or more polypeptide chains.  All proteins in all species are formed from the same set of 20aminoacids.  Amino Acids (The structural unit of proteins)  Amino acids contain both an amino group and a carboxyl group.  α-Amino acid is an amino acid in which the amino group is on the carbon adjacent to the carboxyl group.  Protein Nomenclature Peptides 2 –50 amino acids Proteins >50 amino acids Three letter code: –Met-Gly-Glu-Thr-Arg-His Single letter code: –MGETRH  Types and functions of proteins Role Examples Functions They are catalysts, meaning that they speed the reactions up 1. Enzymes Amylase, - Digestive enzymes break down nutrients in food lipase, pepsin into small pieces that can be readily absorbed - All chemical reaction of the body are catalyzed by enzymes 2. Transport Hemoglobin Carry substances throughout the body in blood (e.g. molecules, ions…) Actin, 3. Structure collagen, Build different structures keratin 4. Receptors Mediate chemical, electrical and hormonal stimuli  Types and functions of proteins Role Examples Functions 5. Hormones Insulin, Coordinate the activity of different body systems glucagon 6. Defense Antibodies Protect the body from foreign pathogens 7. Contraction Myosin Carry out muscle contraction - Albumin - Serve as biological reserves of metal ions and 8. Storage amino acids - Ferritin - A protein that stores iron in the liver - Biochemistry is of chemistry of life. - The major biomolecules in different organisms. - There are two forms of living cells eukaryotes and prokaryotes. - Introduction to Proteins structure and function.  Introduction to Biochemistry link https://www.youtube.com/watch?v=9MfGXc2qKXo&list=PLluIsqNl4jcqXszPTyKWVYmSfT00E qx8q