Chapter 2: The Chemical Basis of Life (PDF)

CHAPTER 2 THE CHEMICAL BASIS OF LIFE Basic Chemistry Subatomic Particles Matter: anything that occupies space and Proton: positive charged particles located has mass ( so...

CHAPTER 2 THE CHEMICAL BASIS OF LIFE Basic Chemistry Subatomic Particles Matter: anything that occupies space and Proton: positive charged particles located has mass ( solid, liquid, gas) inside nucleus Mass: amount of matter in an object Neutron: neutral charged particle located Weight: gravitational force acting on object inside nucleus Electron: negative charged particle located Elements of Atoms outside the nucleus Element - Simplest form of matter Atomic Number and Atomic Mass - Example: C, H, O, N, Ca, K, Na, Cl Atomic Number: the number of protons in each atom Atom Mass Number: the number of protons and - Smallest particle of an element neutrons in each atom - Contains protons, electrons, and neutrons Chemical Bonds Chemical bonds occur when outermost Model of an atom electrons (valence shell electrons) are transferred or shared between atoms Types of Chemical Ionic Covalent Hydrogen Ion and Ionic Bonding Ion: a charged atom formed because of a donation or gain of an electron(s) Planetary Models of atomic Structure - Example: Na Ionic Bonding: occurs when there is an attraction between two oppositely charged ions - Example: NaCI KYLA ELYSHA MARIE P. RONDAN BSN 1- F 1  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Hydrogen Bonding A hydrogen bond forms when the positive end of one polar molecule is weakly attracted to the negative end of another polar molecule The hydrogen bond is a weaker bond than the ionic or covalent bonds Covalent Bonding Polar Covalent Bonds Occurs when atoms share one or more pairs Polar covalent bonded molecules, like water, of electrons have a positive end and a negative end - Example: hydrogen molecule Polar Covalent Bonds: form when there is an unequal sharing of electrons - Example: H2O (water) Polar Molecules: have an asymmetrical electrical charge Nonpolar Molecules: have symmetrical Hydrogen Bonding electrical charge A hydrogen bond forms when positive end of one polar molecule is weakly attracted to the negative end of another polar molecule The hydrogen bond is a weaker bond than the ionic or covalent bonds KYLA ELYSHA MARIE P. RONDAN BSN 1- F 2  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Molecules and Compounds Energy and Chemical Reactions Molecule Exchange Reaction: - 2 or more atoms chemically - Combination of synthesis and combine decomposition reaction - Example: water (H2O) - Example: AB + CD —--> AC +BD - Example: HCI + NaCI --> NaCI + Compound H2O - Chemical combination of 2 or more different types of atoms Reversible Reactions - Example: NaCI - Occur when the reaction can run in the opposite direction, so that the products are converted back to the Chemical Reactions original reactants Occur when there is a formation or breaking of chemical bonds between atoms, ions, Equilibrium: molecules, or compounds. - When the rate of the product Reactants: substances that enter into the formation equals the rate of reaction reactant formation Products: substances that result from the reaction A+B —-----------> C+D Reactants product Types of Chemical Reaction Synthesis Reaction - Build a new molecule - Energy-requiring - Example: ADP + P = ATP Energy Decomposition reaction: Energy is the capacity to do work - Breakdown molecule Work is the moving of matter - Energy-releasing Kinetic energy is energy in motion - Example: ATP ----> ADP + P Potential energy is stored energy KYLA ELYSHA MARIE P. RONDAN BSN 1- F 3  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Chemical Energy Acids and Bases Is a form of potential energy stored in Acid chemical bonds. - A proton H+ donor Food molecules such as glucose contain - pH below 7 potential energy - Example: HCI (hydrochloric acid) An example of a reaction that releases energy is the breakdown of ATP ( adenosine Base triphosphate) to add ADP ( adenosine - A proton H+ acceptor diphosphate) ATP —---> ADP + P - pH above 7 - Example: NaOH (sodium hydroxide) Rate of Chemical Reactions The rate at which a chemical reaction proceeds is influenced by several factors - Concentration of the reactants - Temperature - Catalyst Concentration - Of the reactants: within limits the limits the higher the concentration of reactants the faster the rate Temperature - Within limits, the higher the temperature the faster the rate Inorganic Chemistry versus Organic Chemistry Catalyst In organic Chemistry: deals with those - Increases the rate of a reaction without itself substances that do not contain carbon being permanently changed or depleted. Organic Chemistry: is the study of carbon containing substances Exception: some carbon containing compounds are not organic in that they do not also contain hydrogen, such as CO2 (carbon dioxide) KYLA ELYSHA MARIE P. RONDAN BSN 1- F 4  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Organic Molecule Characteristics of Lipids Carbon’s ability to form covalent bonds with Contain C, H, O other atoms makes it possible the formation Contain a lower proportion of oxygen to of large, diverse, complicated molecules for carbon than do carbohydrates life. Insoluble in water The four major groups of organic molecules Examples: fats, oils, cholesterol, triglycerides, essential to living organisms are phospholipids carbohydrates, lipids, proteins, and nucleic acids Function of Lipids Carbohydrates Long term energy storage Disaccharide Insulates against heat loss - 2 sugars Protective cushion for organs - Example: glucose + fructose = Cholesterol is part of the cell membrane sucrose structure - Example: glucose + galactose = lactose Types of Lipids Polysaccharide Saturated: - Many sugars - Single covalent bonds between - Example: starch, grain, vegetables, carbon atoms glycogen - Examples: beef, pork, whole milk, cheese, eggs Function of Carbohydrates Unsaturated Short-term energy storage - One or more double covalent bonds Converted to glucose quickly between carbons Glucose is used to make ATP (energy) - Examples: olive oil, fish oil, Brain cells require glucose sunflower oil KYLA ELYSHA MARIE P. RONDAN BSN 1- F 5  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Phospholipids Protein Denaturation Protein denaturation occurs when the hydrogen bonds the maintain shape of a protein are broken and the protein becomes nonfunctional Factors that can cause denaturation are: high temperatures and/or improper pH Amino acid & Bonding Characteristics of Proteins Contains C,H,O,N Amino acids are the building blocks 20 different naturally occurring amino acids Linear Sequence of Amino Acids in a Amino acids contain an amine (NH2) Protein group and carboxyl group Amino acids are not stored, so a daily supply is required Functions of Proteins Used to make skin, hair, nails, muscles Part of the hemoglobin molecule Act as enzymes Immune system functions Protein Folding Muscle contractions ( actin and myosin) Part of the cell membrane KYLA ELYSHA MARIE P. RONDAN BSN 1- F 6  CHAPTER 2 THE CHEMICAL BASIS OF LIFE Enzyme Action Enzymes Enzymes are organic catalysts that increase the rate at which biochemical reactions proceed without the enzyme being permanently changed. Enzymes work by lowering the energy of activation Nucleic Acids Composed of C, H, O, N, P Examples: DNA (deoxyribonucleic acid) Structure of DNA and RNA (ribonucleic acid) Nucleotides are the building blocks Nucleotides are composed of a nitrogen base, phosphate, and 5-carbon sugar Adenosine Triphosphate (ATP) ATP is an especially important organic molecule found in all living organisms It consist of adenosine ( the sugar ribose with the organic base adenine) and three phosphate groups Structure of ATP ATP is often called the energy currency of cells because it is capable of both storing and providing energy Activation Energy & Enzymes KYLA ELYSHA MARIE P. RONDAN BSN 1- F 7