Chemistry P1 PDF

Week 2: Biomedical Issues 1  RU Voting? Oct. 15 deadline to register to vote in NJ – Rutgers Center for Youth Political Participation – https://cypp.rutgers.edu/ru-voting/ Not in NJ use VOTE.org to find information about your state!...

Week 2: Biomedical Issues 1  RU Voting? Oct. 15 deadline to register to vote in NJ – Rutgers Center for Youth Political Participation – https://cypp.rutgers.edu/ru-voting/ Not in NJ use VOTE.org to find information about your state! 2 3 Chemistry – Part I (Inorganic) 4  Water Water is critical for human survival. – Over ½ of your body’s weight is from water Dehydration can lead to impaired physical and mental abilities, cramps, and heat exhaustion. – We lose about 3 liters/day – We replace about 1.5 liter/day in food. – The other 1.5 liter must come from drinking. Where is water found in the body? 5  Elements of Water Elements are the fundamental forms of matter – Simplest chemical compounds, composed of atoms – Cannot be broken down by normal physical means – Many elements have been described (see periodic table), but only a few are found in living organisms Water is made up of the elements hydrogen and oxygen. 6 2.1 Water: Essential to Life Table 2.1 Belk&Borden Human Biology 7 2009  Neutral atom: Ion: Elements with the same number of protons but different number of neutrons are called isotopes radioactive isotope Fig. 2.1 Goodenough & McGuire Biology of Humans 2017 8 https://www.epa.gov/radon 9  Structure of Water Water (H2O) – Two hydrogens for each oxygen – The hydrogen and oxygen are joined by a chemical bond – A molecule is made of two or more atoms. If the atoms differ, the substance is called a compound. 10  Chemical Bonds The atoms in a compound are held together by covalent, ionic or hydrogen bonds Covalent bonds the strongest bonds form when atoms share electrons 11  Chemical Bonds An ion is an atom or group of atoms with a positive or negative electrical charge Ionic bonds “weaker” than covalent bonds result from the attraction of oppositely charged ions, rather than shared electrons Ionic bonds can be disrupted with liquids that contain electrical charges. 12  Chemical Bonds Fig. 2.9 Goodenough & McGuire Biology of Humans 2017 13  Chemical Bonds Hydrogen bonds are the attraction formed between a slightly positively charged hydrogen atom and another slightly negatively charged atom 14  Concept Check 1 Any molecule containing oxygen can be polar. The structure of methanol (CH3OH) is shown here. Which part(s) of this molecule will have a partial negative charge and which part(s) will have a partial positive charge? Why? 15  Water as a Solvent Water is a good solvent. – Solute – Solvent – Solution Water is a good solvent because it is polar… 16  Water as a Solvent Any molecule with charged atoms will dissolve in water. These molecules are hydrophilic – Atoms of a molecule without a charge are nonpolar. These do not mix with water, e.g., oil, which is hydrophobic - 17  Chemical Reactions Water facilitates chemical reactions. – Water is a powerful solvent. – Reactants – Products – Example: carbon dioxide and water form carbonic acid: H2O+CO2  H2CO3 18  19 https://bit.ly/4dZZxHR  Why we Sweat When sweat evaporates, it cools the skin and blood near the skin. Too much sweating may cause dehydration and rise in body temperature. 20 http://hubpages.com/hub/Stop-Excessive-Facial-and-Underarm-Sweating  Acids and Bases pH: measuring the activity of ions H2O H+ + OH– The pH scale measures the relative percentage of H+ ions in a solution. Water is pH 7 (neutral). Acids have a pH below 7, with the lower numbers more acidic. Bases have a pH above 7, with the higher numbers more basic. The pH scale runs between 0 and 14. 21 22  Acids and Bases Hydrogen ion: Hydronium ion: Hydroxyl ion: The pH measures the relative percentage of: Make a pH table: H+ pH # Acids Bases 23  Concept Check 2 When added to water, sodium hydroxide (NaOH) dissociates into Na+ and OH-. Write out this reaction. Would you expect sodium hydroxide to increase or decrease pH? Why? 24  Acids and Bases Homeostasis is the maintenance of a stable internal environment. Buffers can take up excess H+ and OH– ions. Many body fluids have the buffering capacity to maintain a constant internal environment 25  Stretch Break! Get up Move around and talk to people! 26  Class Conduct/AI Policy Review/Updates 27 Chemistry – Part 2 (Organic) 28  Chemistry of Life “Organic” refers to life. Organic chemistry deals with carbon- containing chemicals. Carbon can form covalent bonds with up to four elements. 29  The Major Molecules of Life Biological macromolecules are the giant molecules of life – They are long chains called polymers made of repeating units called monomers 30  Structure and Function of Macromolecules Organic chemicals found in living organisms come in four categories: – Carbohydrates – sugars – Lipids – fats, phospholipids and steroids – Proteins – Nucleic Acids – RNA and DNA (will discuss in a later lecture) 31  32 Fig. 2.13 Goodenough & McGuire Biology of Humans 2017  33 Fig. 2.13 Goodenough & McGuire Biology of Humans 2017  Animated Example Hydrolysis and Dehydration https://youtu.be/ZMTeqZLXBSo 34 Carbohydrates (sugars & starches) – Major source of energy for cells – The energy is stored in the bonds between the atoms in the sugar molecule. – E.g.: Glucose, a monosaccharide, consisting of a single ring structure. – Chemical formula: C6H12O6 35  Carbohydrates Lactose (milk sugar) is a disaccharide (2 rings), composed of glucose and galactose. Sucrose, the sugar used in baking, is a disaccharide, composed of glucose and fructose. 36 Fig. 2.15 Goodenough & McGuire Biology of Humans 2017  Carbohydrates Polysaccharides are polymers of sugar monomers. Cellulose Starch 37  Proteins Proteins serve many important functions. – Proteins called enzymes speed up chemical reactions. – Proteins regulate gene expression. – Proteins are important structural components of cells. – Proteins (hormones) function as chemical messengers. – Immune function (antibodies) 38  Proteins Proteins – large molecules made up of amino acids There are 20 different amino acids, and some can be synthesized by the body. Those the body cannot synthesize are called essential amino acids. These must come from the diet. Kwashiorkor 39  Amino Acid Structure Amino acids are made of carbon, hydrogen, oxygen, and nitrogen. Nitrogen is part of an amino group on one end of the amino acid. A carboxyl group is on the other end. 40 Fig. 2.20 Goodenough & McGuire Biology of Humans 2017  Levels of Protein Structure Long polymers of amino acids are named polypeptides because the covalent bond joining the amino acids in the chain is a peptide bond. The linear sequence of amino acids in a peptide chain is called the protein’s primary structure. 41 Fig. 2.21 Goodenough & McGuire Biology of Humans 2017 42  Protein Structure Heating a protein breaks the bonds that maintain its structure. This is called denaturation. 43 44  Concept Check 3 Some amino acids have very hydrophobic side chains (e.g. valine). Suppose a section of a protein contains a long series of these hydrophobic amino acids. How would you expect this portion of the protein to behave when in water? 45  Lipids Lipids – partially or entirely hydrophobic substances. – They are made primarily of hydrogens and carbons. – They store long-term energy, protect vital organs, and form cell membranes – There are three kinds: triglycerides (fats), phospholipids, and steroids. 46  Triglycerides Triglycerides (Fats) are a source of energy. – Fat structure includes glycerol and three long hydrogen-and-carbon rich (hydrocarbon) chains, called fatty acids. 47 Triglycerides 48  Triglycerides The double bonds in unsaturated fats make the structures kink. Vegetable oils are unsaturated fats. Plants tend to be richer in unsaturated fats than animals. Saturated fats pack together tightly. That is why they are solid at room temperature, e.g., butter. Figure 2.18c Belk&Borden Human Biology 2009 49 50 51  Phospholipids Phospholipids – Similar to triglycerides except each glycerol molecule is attached to two fatty acid chains, not three. – The third bond in a phospholipid is to a phosphate functional group, –PO4 52  Steroids Steroids are a unique group of lipids that consist of four ring compounds. 53 Fig. 2.19 Goodenough & McGuire Biology of Humans 2017  Concept Check 4 Which is healthier, corn oil (grown in Nebraska) or cottonseed oil (grown in Alabama)? Why? 54  Reminders Concept checks due tonight! Keep up with the readings and reviewing your notes each week. Office Hours Tuesday 11am-12pm and Wednesday 2-3pm stop by my office or on zoom. Check your voter registration status! 55