Lecture 1 Chemical Level of Organization 1 PDF

Chemical level of organization 1 Dr. Elita Partosoedarso Kaltura Recordings: Part A, Part B, Part C YouTube Recording 1  Chemical level of organization overview...

Chemical level of organization 1 Dr. Elita Partosoedarso Kaltura Recordings: Part A, Part B, Part C YouTube Recording 1  Chemical level of organization overview Types of substances Basics Types of bonds Chemical reactions and energy Chemical level of organization Water Inorganic Salts, electrolytes, anions, cations compounds Acid, base, buffer, pH O2 and CO2 Carbohydrates Organic Lipids compounds (next lecture) Proteins & Enzymes Nucleotides 2  1. Element: pure substance that cannot be created or broken down by ordinary chemical means Elements and Compounds 2. Compound: substance composed of 2+ elements joined by chemical bonds 3. Atom: smallest quantity of an element with properties unique to it 4. Bond: electrical attraction that holds atoms in the same vicinity Elements of the Human Body 3  Types of bonds 1.1 Ionic bond ○ ongoing, close association between ions of opposite charge. 3 ○ Example: bond between sodium and chloride ions in salt 2.2 Hydrogen bond ○ formed when a weakly positive hydrogen atom already bonded 2 to one electronegative atom is attracted to another electronegative atom from another molecule. ○ Example: bond between hydrogen and oxygen in different water molecules 3.3 Covalent bond ○ chemical bond in which two atoms share electrons in a mutually stabilizing relationship ○ Example: bond between hydrogen and oxygen in a single water 1 molecule 4. Not all bonds are equal in strength: The ________ bond is the strongest bond whereas the ______ is the weakest. 4  The Role of Energy in Chemical Reactions Chemical energy: potential energy which is stored in chemical bonds. Energy is used when chemical bonds are formed and produced when bonds are broken Types of reactions 1 Synthesis reaction, also known as a ________ reaction 1. ○ Chemical bond is formed between 2 simpler substances to form a more 2 1 complex product ○ _________ energy ○ Example: A + B + Energy → AB 2 Decomposition reaction, also known as a ________ reaction 2. ○ Chemical bond of a substance is broken, forming two or more simpler products ○ Example: AB → A + B + Energy ○ _________ energy 3. Exchange reaction 1 ○ Reaction which has both decomposition and synthesis reactions, resulting in the formation of two new compounds ○ Example: AB + CD → AD + CB 4. Components of reactions A. Reactant(s) or substrate(s) are substance(s) that enter into a reaction B. Product(s): substance(s) produced by the reaction 5 2  Factors Influencing the Rate of Chemical Reactions Properties of the Reactants ○ Reactions occur faster when there is a _______ surface area available for reactions ○ Reactions occur faster when reactants are in a _________ state and slowest when they are in a ____________ state ○ Reactions occur faster when the reactants are _____________ in size Temperature: Reactions occur faster with _________ temperatures Concentration: Reactions occur faster with ____________ concentration of reactants Pressure: Reactions occur faster with ____________ pressure of the container that the reactants are in Enzymes (Organic Catalysts) lowers the activation energy (level of energy needed to start the reaction) and will ________ the rate of reaction 6 Overview of Organic and Inorganic Compounds Inorganic compounds Organic compounds Water, CO2, O2, acids, bases, Carbohydrates, lipids, Examples salts, electrolytes (Na+, K+, Ca+) proteins, ATP, nucleic acids (DNA, RNA) Contains carbon atom Contain carbon-carbon (C—C) or carbon-hydrogen (C—H) bonds Functional groups attached to carbon-containing core 7  Inorganic Molecules- Water (most abundant and important) Properties of water 1. Universal solvent: provides environment for chemical reactions to occur; ionizes substances, dissolves solutes. Most chemical reactions in the body occur in aqueous solutions 2. Lubricant and cushion: Protects against trauma and friction 3. High specific heat (“heat sink”): can lose and gain large amounts of heat with little change in its own temperature: allows us to maintain a relatively constant body temperature 4. Role in chemical reactions: breaking and creation of water molecules is key in some chemical reactions ______________ ______________ reaction ______________ reaction 8  Fluid Compartments In the body, water is kept in different fluid compartments, separated by 1 cell membrane. Movement of water (and its components) is controlled by the cell membrane and its components. This is necessary to maintain optimal function. 3 Fluid Compartments in the body 4 1. 1 Intracellular fluid (ICF): water inside the cells 2 ○ largest body fluid compartment by volume (60% or 25 L in adult males) ○ Facilitates intracellular chemical reactions that maintain life 1 2.2 Extracellular fluid (ECF): water outside the cells 3 ○ internal environment of the body ○ provides a means to transport substances to and from cells ○ mainly plasma and IF, minor amounts in lymph, CSF, joint fluids 3 Plasma: fluid component of blood (20% total water volume) 3. 4 4 Interstitial fluid (IF): fluid that surrounds all cells not in the blood 4. 9  Composition of Body Fluids Plasma and interstitial fluid (two main components of ECFs) have almost identical chemical composition while that of ICF (intracellular fluid) is quite different. Ions enter via digestive tract and exit mainly via the urinary tract. Loss can also occur via excessive sweating, severe vomiting or diarrhea 1. Main differences between blood and IF ○Total ions: slightly more in ________________ ○Protein anions: normally only in ________________ 2. Main differences between ECF and ICF Sodium (Na+): higher concentration in_________ Potassium (K+): higher concentration in_________ Bicarbonate (HCO3-): higher concentration in_________ Chloride (Cl-): higher concentration in_________ Protein anions: higher concentration in_________ The concentration differences between Na+ and K+ between the ECF and ICF is maintained by the Na+/K+ ATPase pump 10  Components of Fluid Compartments 2 6 1.1 Solutes: dissolved substances in a solution, eg ______________ 5 2.2 Solvent: solution that solutes are dissolved in, eg _________ 3 3.3 Salt: substances composed of anions and cations, eg _____ 4. Electrolytes: salts that dissociate into its charged solutes in solution and that can conduct an electrical current, eg _________ 5.5 Anions: substances with a negative charge, eg _________ 6.6 Cations: substances with a positive charge, eg _________ 7 7. Acid: substance that dissociates into hydrogen ions (H+) and anions. 7 2 An acidic solution has a pH of ____ 1 8.8 Base: substance that dissociates into hydroxyl ions (OH–) and cations. A basic solution has a pH of ____ 8 2 11 1  The Concept of pH pH is the relative measure of the acidity or alkalinity of a solution. Water with a pH = 7 in is ____________ Water with a pH < (less than) 7 is ____________ Water with a pH > (greater than) 7 is __________ Blood with a pH between 7.35-7.45 is __________ Blood with a pH < (less than) 7.35 is __________ Blood with a pH > (greater than) 7.45 is __________ Implications pH 7 is ____________ in water and ____________ in blood pH 7.25 is ____________ in water and ____________ in blood pH 7.4 is ____________ in water and ____________ in blood 12  Buffers and their effect on acids and bases 1. A buffer is a solution of a weak acid and its conjugate base which can neutralize small amounts of acids or bases in body fluids, it does not prevent pH changes, but help to minimize large swings in pH 2. Buffer pairs are present in both plasma or intracellularly to help maintain blood within its normal range Without buffer With buffer Acid is added to a solution Strong base is added to a solution Strong acid is added to a solution 13  Inorganic Molecules- O2 and CO2 Both are closely related to cellular respiration 1. Oxygen (O2) ○ required to complete decomposition reactions ○ Causes the release of energy in the body 2. Carbon dioxide (CO2) ○ produced as a waste product: reason why venous blood is more acidic than arterial blood ○ helps maintain appropriate acid-base balance in the body carbonic anhydrase CO2 + H2O ↔ H2 CO3 ↔ HCO3- + H+ carbon carbonic bicarbonate hydrogen dioxide water acid ion ion 14