Week 1: The Chemical Basis of Life PDF

LO1_The Chemical Basis of Life Week1_PPT © McGraw Hill, LLC  Because learning changes everything.® Chapter 02 The Chemical Basis of Life Seeley’s ANATOMY & PHYSIOLOGY Thirteenth Edition Cinnamon VanPutte, Je...

LO1_The Chemical Basis of Life Week1_PPT © McGraw Hill, LLC  Because learning changes everything.® Chapter 02 The Chemical Basis of Life Seeley’s ANATOMY & PHYSIOLOGY Thirteenth Edition Cinnamon VanPutte, Jennifer Regan, Andrew Russo © 2023 McGraw Hill, LLC. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill, LLC.  Lecture Outline To thoroughly understand the structure and functions of the human body, it helps to begin with the materials that compose our bodies and how those materials interact. © McGraw Hill, LLC 3  Common Elements in the Body The four most common elements in the body are hydrogen (H), carbon (C), nitrogen, (N), and oxygen (O). Other elements that are important to body function are found in small or trace amounts and include fluorine (F), sodium (Na), magnesium (Mg), phosphorus (P), sulfur (S), chlorine (Cl), potassium (K), calcium (Ca), iron (Fe), and iodine (I). © McGraw Hill, LLC 4  Atomic Structure Atoms: composed of subatomic particles. Neutrons: no electrical charge. Protons: one positive charge. Electrons: one negative charge. Nucleus: formed by protons and neutrons. Most of the volume of an atom occupied by electrons. Represented as an electron cloud. Access the text alternative for slide images. © McGraw Hill, LLC 5  Electrons and Chemical Bonding 1 Chemical bonds are formed when electrons in the outermost energy level (valence shell) are either shared with or transferred to another atom. Ionic Bonding: electrons are transferred from one atom to another. Covalent Bonding: two or more atoms share electron pairs. © McGraw Hill, LLC 6  Molecules and Compounds Molecules: two or more atoms chemically combined to form an independent unit. Example: hydrogen molecule (H2); water molecule (H2O) Compounds: a substance composed of two or more different types of atoms chemically combined. Example: water (H2O); sodium chloride (NaCl) © McGraw Hill, LLC 7  Hydrogen Bonds Occur when the positively charged H of one molecule is attracted to the negatively charged O, N, or F of another molecule. For example, in water, the positively charged hydrogen atoms of one water molecule bond with the negatively charged oxygen atoms of other water molecules. Intramolecular hydrogen bonds play an important role in determining the shape of complex molecules. © McGraw Hill, LLC 8  Solubility and Dissociation Solubility: ability of one substance to dissolve in another. For example, sugar or salt dissolves in water but oils do not. Dissociation (separation): in ionic compounds, cations are attracted to negative end and anions attracted to positive end of water molecules; the ions separate and each becomes surrounded by water molecules. Access the text alternative for slide images. © McGraw Hill, LLC 9  Electrolytes and Nonelectrolytes Electrolytes: solutions made by the dissociation of cations (+) and anions (−) in water. Have the capacity to conduct an electric current. Currents can be detected by electrodes. Nonelectrolytes: solutions made by molecules that dissolve in water, but do not dissociate; do not conduct electricity. Maintaining a proper electrolyte balance is important for many physiological body processes. © McGraw Hill, LLC 10  Synthesis Reactions Two or more reactants chemically combine to form a new and larger product. Collective term for synthesis reactions in body is anabolism. Chemical bonds made; energy stored in the bonds. Responsible for growth, maintenance and repair. Dehydration reaction: synthetic reaction where water is a product. Produce chemicals characteristic of life: carbohydrates, proteins, lipids, and nucleic acids. Also involved in formation of adenosine triphosphate (ATP). Access the text alternative for slide images. © McGraw Hill, LLC 11  Decomposition Reactions A large reactant is broken down to form smaller products. Collective term for decomposition reactions in body is catabolism. Chemical bonds broken; energy released. Hydrolysis reactions: water is split into two parts that contribute to the formation of the products. Examples: digestion of food molecules and the breakdown of ATP to form ADP and inorganic phosphate with a release of free energy. Access the text alternative for slide images. © McGraw Hill, LLC 12  Reversible Reactions Chemical reactions in which the reaction can proceed either from reactants to products or from products to reactants. Equilibrium: rate of product formation is equal to rate of reactant formation. Example: CO2 reacting with water to form bicarbonate and in blood plasma. © McGraw Hill, LLC 13  Energy and Chemical Reactions Access the text alternative for slide images. © McGraw Hill, LLC 14  2.3 Inorganic Chemistry Inorganic Chemistry: substances that do not contain carbon-hydrogen bonds. Water, oxygen, carbon dioxide, calcium phosphate, metal ions. Organic Chemistry: study of carbon-containing substances. Exceptions: CO, CO2, and. ( lack C-H bonds) © McGraw Hill, LLC 15  Water Its polar nature influences interaction with other molecules. Hydrophilic: substances attracted to water; “water-loving”. Hydrophobic: substances not attracted to water; “water- fearing”. Cohesion and adhesion properties. Cohesion is the attraction of one water molecule to another; creates a surface tension Adhesion is the attraction of water molecules to other molecules; causes the upward movement of water in the xylem of plants. 50 to 60% of body, 92% of blood is composed of water. © McGraw Hill, LLC 16  Acids and Bases Acid: a proton donor or any substance that releases hydrogen ions. Base: a proton acceptor or any substance that binds to or accepts hydrogen ions. Many bases acts as hydrogen receptors because they release hydroxide ions when they dissociate. © McGraw Hill, LLC 17  The pH Scale 1 Refers to the hydrogen ion concentration in a solution. Neutral: pH of 7 or equal amounts of hydrogen and hydroxide ions. Acidic: pH of less than 7 with a greater concentration of hydrogen ions. Alkaline (basic): pH of greater than 7 and a greater concentration of hydroxide ions. Access the text alternative for slide images. © McGraw Hill, LLC 18  The pH Scale 2 (Oven cleaner) ©Jeffrey B. Banke/Shutterstock; (Bleach) ©dcwcreations/Shutterstock; (Household ammonia) ©McGraw Hill Education/Terry Wild Studio, photographer; (Blood [pH7.4]) ©Andrii Vodolazhskyi/Shutterstock; (Distilled water [pH7.0]) ©kobi nevo/Shutterstock; (Black coffee) ©Pixtal/ SuperStock; (Tomatoes) ©Alamy; (Vinegar, cola, beer) ©Iconotec/Glow Images; (Lemon juice) ©lynx/iconotec.com/Glow Images Access the text alternative for slide images. © McGraw Hill, LLC 19  Normal and Unnormal body pH The normal pH range for human blood is 7.35 to 7.45. If blood pH drops below 7.35, a condition called acidosis occurs in which the nervous system becomes depressed and the individual may become disoriented and possibly comatose. If blood pH rises about 7.45, a condition called alkalosis occurs in which the nervous system becomes overexcitable and the individual may be very nervous or have convulsion. © McGraw Hill, LLC 20  Four major groups of organic molecules essential to living organisms Carbohydrates: composed of carbon, hydrogen, oxygen. Divided into monosaccharides, disaccharides, polysaccharides. Energy sources, structure, and bulk for elimination. Water soluble Lipids: composed mostly of carbon, hydrogen, oxygen. Relatively insoluble in water. Functions: protection, insulation, physiological regulation, component of cell membranes, energy storage. Proteins: composed of carbon, hydrogen, oxygen, nitrogen, sometimes sulfur. Functions: regulate processes, aid transport, protection, muscle contraction, structure, energy. Nucleic Acids: composed of carbon, hydrogen, oxygen, nitrogen, phosphorus. Examples: ATP, DNA, RNA. © McGraw Hill, LLC 21  Carbohydrates: Monosaccharides Simple sugars; major one is glucose. Six-carbon sugars like glucose, fructose, and galactose are important in the diet as energy sources. These are isomers, molecules that have the same number/types of atoms but differ in their 3-D arrangement. Five-carbon sugars are components of ATP, DNA and RNA. Access the text alternative for slide images. © McGraw Hill, LLC 22  Carbohydrates: Disaccharides Two simple sugars bound together by a dehydration reaction. Examples: sucrose (glucose + fructose), lactose (glucose + galactose), maltose (2 glucose). © McGraw Hill, LLC 23  Carbohydrates: Polysaccharides Long chains of many monosaccharides (glucose). Storage molecules for monosaccharides (energy storage) and form part of cell surface markers. Glycogen formed by animals. Starch and cellulose formed by plants. Starch in food is used as a source of monosaccharides. Cellulose in food acts as fiber (bulk) in the diet. © McGraw Hill, LLC 24  Lipids: Fats (Triglycerides) Ingested and broken down by hydrolysis. Triglycerides: composed of glycerol and fatty acids. Each fatty acid has a carboxyl group. Fatty acids combine with glycerol to form triglyceride. Functions: protection, insulation, energy source. Access the text alternative for slide images. © McGraw Hill, LLC 25  Saturated and Unsaturated Fatty Acids Fatty acids may be saturated or unsaturated. Saturated – contains all single bonds in the carbon chain, which produces a more rigid structure; generally solid Unsaturated – contains one (mono) or more (poly) double bonds in the carbon chain, which produces a more relaxed structure; generally liquid Better because they do not stick to the inside of blood vessels. Trans fats – unsaturated fats that are artificially altered to be more saturated. Are the highest cardiovascular risk fat. Access the text alternative for slide images. © McGraw Hill, LLC 26  Lipids: Phospholipids One fatty acid replaced with a phosphate group; polar (hydrophilic) at one end; nonpolar (hydrophobic) at the other. Function: important structural component of cell membranes. Access the text alternative for slide images. © McGraw Hill, LLC 27  Lipids: Steroids Lipids with four ring like structures. Examples: Cholesterol – component of cell membranes; precursor for steroid hormones. Bile salts – digestion and absorption of lipids. Reproductive steroid hormones - estrogen, progesterone, and testosterone Access the text alternative for slide images. © McGraw Hill, LLC 28  Proteins Amino acids: building blocks of protein. Peptide bonds: covalent bonds formed between amino acids during protein synthesis by dehydration. © McGraw Hill, LLC 29  Amino Acids All amino acids have the same general structure of an amino group (-NH2), a carboxyl group (-COOH),and a hydrogen off the central carbon. The R side chain is what make the 20 amino acids different. Access the text alternative for slide images. © McGraw Hill, LLC 30  Protein Structure 1 Primary structure: the amino acid sequence Secondary structure: results from hydrogen bonding between amino acids. Pleated (folded) sheets. Helices. Denaturation: change in shape caused by breaking of H-bonds by heat or pH changes. Access the text alternative for slide images. © McGraw Hill, LLC 31  Protein Structure 2 Tertiary structure: large-scale folding due to interactions within protein and surrounding environment which is generally water. Polar regions tend to remain unfolded and in contact with water while nonpolar regions tend to fold inward away from water. Stabilized by disulfide bonds. Determines shape of a domain and the function of the protein. © McGraw Hill, LLC 32  Protein Structure 3 Quaternary structure: results from the association of two or more proteins (subunits). © McGraw Hill, LLC 33  Nucleic Acids: DNA and RNA Nucleic acids are composed of nucleotides. Include deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and ATP. Access the text alternative for slide images. © McGraw Hill, LLC 34  Nitrogenous Bases Nucleotides. Composed of a five-carbon sugar (deoxyribose or ribose), a nitrogenous base, and a phosphate. Single ring bases Double ring bases Access the text alternative for slide images. © McGraw Hill, LLC 35  DNA Genetic material of cells copied from one generation to next. Composed of 2 strands of DNA nucleotides. A and T; G and C = complementary base pairs held by H- bonds. Connect like rungs of a ladder and twist to form double helix. The two strands of a DNA molecule are antiparallel. Sugar-phosphate backbones oriented in opposite directions. Gene: sequence of bases that codes for synthesis of RNA or protein. Base sequence determines the primary structure of a protein. © McGraw Hill, LLC 36  Structure of DNA Access the text alternative for slide images. © McGraw Hill, LLC 37 Because learning changes everything. ® www.mheducation.com © 2023 McGraw Hill, LLC. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill, LLC.  Thank You 800 MyHCT (800 69428) www.hct.ac.ae © McGraw Hill, LLC