Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Chapter 2 Basic Chemistry © 2015 Pearson Education, Inc.

Reading Pages  Patterns of Chemical Reactions  Acids/Bases; pH; Homeostasis

© 2015 Pearson Education, Inc. Hydrogen Bonds  Hydrogen bonds  Weak chemical bonds  Hydrogen is attracted to the negative portion of a polar molecule  Provides attraction between molecules  Responsible for the surface tension of water  Important for forming intramolecular bonds, as in protein structure

© 2015 Pearson Education, Inc. Patterns of Chemical Reactions- 3 types  Synthesis  Decomposition  Exchange

© 2015 Pearson Education, Inc. Synthesis reaction (A  B  AB)  Atoms or molecules combine  Energy is absorbed (required) for bond formation  All anabolic (constructive) activities in the body  Example:  Building tissues for growth/development or repair required building structures from protein synthesis

© 2015 Pearson Education, Inc. Figure 2.10a Patterns of chemical reactions. (a) Synthesis reactions Smaller particles are bonded together to form larger, more complex molecules. Example Amino acids are joined together to form a protein molecule. Amino acid molecules Protein molecule

© 2015 Pearson Education, Inc. Decomposition reaction (AB  A  B)  Molecule is broken down  Chemical energy is released  All catabolic (destructive) activities in the body  Ex: Digestion: some molecules are too large to use so they must be broken down  breaking down glycogen to release glucose  breaking proteins down into amino acids

© 2015 Pearson Education, Inc. Figure 2.10b Patterns of chemical reactions. (b) Decomposition reactions Bonds are broken in larger molecules, resulting in smaller, less complex molecules. Example Glycogen is broken down to release glucose units. Glucose molecules Glycogen

Exchange reaction (AB  C  AC  B and AB  CD  AD  CB)  Involves both synthesis and decomposition reactions as bonds are both made and broken  Switch is made between molecule parts, and different molecules are made  Just a rearrangement of atoms and molecules  Example:  ATP + glucose > ADP + glucose phosphate  ADP can be recycled and “re-energized” meaning it can store energy again by gaining another phosphate through cellular respiration or other rxs © 2015 Pearson Education, Inc.

Figure 2.10c Patterns of chemical reactions. (c) Exchange reactions Bonds are both made and broken. Example ATP transfers its terminal phosphate group to glucose to form glucose- phosphate. Glucose Adenosine triphosphate (ATP) Glucose- phosphate Adenosine diphosphate (ADP) P PP PPP

© 2015 Pearson Education, Inc. Patterns of Chemical Reactions  Many physiological chemical reactions are reversible  Reversibility is indicated by a double arrow  When arrows differ in length, the longer arrow indicates the more rapid reaction or major direction of progress  Four main factors influence the rate at which these reactions take place  Temp, concentration, particle size, catalyst/enzyme

© 2015 Pearson Education, Inc. Table 2.4 Factors Increasing the Rate of Chemical Reactions.

© 2015 Pearson Education, Inc. Biochemistry: Essentials for Life  Inorganic compounds  Lack carbon  Tend to be small, simple molecules  Include water, salts, and some acids and bases  Organic compounds (macromolecules)  Contain carbon  All are large, covalently bonded molecules  Include:  carbohydrates, lipids, proteins, and nucleic acids

© 2015 Pearson Education, Inc. Important Inorganic Compounds  Water  Most abundant inorganic compound in the body  Its high heat capacity prevents sudden changes in body temperature  important reactant in some chemical reactions  hydrolysis reactions: reactions that require water; water is ADDED to the reaction so molecular bonds can be broken  It cushions- protects brain, developing fetus…

© 2015 Pearson Education, Inc. Figure 2.13b Dehydration synthesis and hydrolysis of biological molecules. (b) Hydrolysis Monomer 2Monomer 1 Monomers linked by covalent bond Monomers are released by the addition of a water molecule, adding OH to one monomer and H to the other. H2OH2O

© 2015 Pearson Education, Inc. Dehydration Synthesis  Monomers (smaller molecules) are joined to form polymers (larger molecules) through the removal of water molecules  A hydrogen ion is removed from one monomer while a hydroxyl group is removed from the monomer it is to be joined with  Monomers unite, and water is released

© 2015 Pearson Education, Inc. Figure 2.13a Dehydration synthesis and hydrolysis of biological molecules. Monomers linked by covalent bond (a) Dehydration synthesis Monomer 1Monomer 2 Monomers are joined by removal of OH from one monomer and removal of H from the other at the site of bond formation. H2OH2O

Important Inorganic Compounds  Salts  Easily dissociate (break apart) into ions in the presence of water  Vital to many body functions  Example: sodium and potassium ions are essential for nerve impulses  All salts are electrolytes (ions that conduct electrical currents)  Sodium and potassium are a HUGE part of nerve impulse transmission © 2015 Pearson Education, Inc.

pH - Measures relative concentration of hydrogen ions  Acids (pH less than 7)  Release hydrogen ions (H + ) when dissolved in water  Are proton donors  Strong acids ionize completely and liberate all their protons; weak acids ionize incompletely  Bases (pH greater than 7)  Release hydroxyl ions (OH – ) when dissolved in water  Are proton acceptors  Strong bases seek hydrogen ions

© 2015 Pearson Education, Inc. Homeostatic Influence on pH  Buffers—chemicals that can regulate pH change  Our bodies contain natural buffers that keep pH constant to maintain homeostasis  The kidneys and lungs regulate pH through filtration/excretion and respiration (respectively)

© 2015 Pearson Education, Inc. Figure 2.12 The pH scale and pH values of representative substances. pH Acidic solution Neutral solution Basic solution OH – H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Increasingly basic Increasingly acidic Neutral [H + ]=[OH – ] Examples 1M Sodium hydroxide (pH 14) Oven cleaner, lye (pH 13.5) Household ammonia (pH 10.5–11.5) Household bleach (pH 9.5) Egg white (pH 8) Blood (pH 7.4) Milk (pH 6.3–6.6) Black coffee (pH 5) Wine (pH 2.5–3.5) Lemon juice, gastric juice (pH 2) 1M Hydrochloric acid (pH 0)