Summary BIOL 235 Midterm 2 (version A) exam study guide solution Athabasca Universities STUDY GUIDE NOTES

BIOL 235 Midterm 2 (version A) exam study guide solution Athabasca Universities STUDY GUIDE NOTES BIOL 235 Midterm 2 (version A) exam study guide solution Athabasca Universities STUDY GUIDE NOTES Chapter 2 objectives After completing this chapter, you should be able to 1. Identify, by name and symbol, the principal chemical elements of the human body. -Oxygen (O): part of water and many organic (carbon-containing) molecules; used to generate ATP, a molecule used by cells to temporarily store chemical energy -Carbon (C): forms backbone chain and rings of all organic molecules – carbs, lipids, proteins and nucleic acids (DNA and RNA) -Hydrogen (H): part of water and most organic molecules; ionized form H+ makes body fluids more acidic -Nitrogen (N): part of all proteins and nucleic acids -Calcium (Ca): contributes to hardness of bones and teeth; ionized form (Ca2+) needed for blood clotting, release of some hormones, contraction of muscle, and many other processes -Phosphorus (P): part of nucleic acids and ATP; required for normal bone and tooth structure -Potassium (K): ionized form (K+) is the most plentiful cation (+ charged particle) in intracellular fluid; needed to generate action potentials -Sulfur (S); part of some vitamins and many proteins -Sodium (Na): ionized form (Na+) is the most plentiful cation in extracellular fluid; essential for maintaining water balance; needed to generate action potentials -Chlorine (Cl): ionized form (Cl -) is the most plentiful anion (- charged particle) in extracellular fluid; essential for maintaining water balance -Magnesium (Mg): Ionized form (Mg2+) is needed for action of many enzymes, molecules that increase the rate of chemical reactions in organisms -Iron (Fe): Ionized forms (Fe2+ and Fe3+) are part of hemoglobin (oxygen-carrying protein in red blood cells) and some enzymes -Trace elements include: aluminum (Al), boron (B), chromium (Cr), cobalt (Co), fluorine (F), iodine (I), manganese (Mn), molybdenum (Mo), selenium (Se), silicon (Si), tin (Sn), vanadium (V), and zinc (Zn) 2. Describe the basic structure of an atom, ion, molecule and compound. -Atoms are the smallest units of matter that retain the properties and characteristics of the element – hydrogen atoms, the smallest atoms, have a diameter of less than 0.1 nanometers, and the largest atoms are only five times larger -Subatomic particles compose different atoms – there are only 3 that are important in understanding the chemical reactions of the human body: protons, neurons and electrons -Atoms of the same element have the same number of protons – atoms of each element have a unique way of losing, gaining, or sharing their electrons with interacting with other atoms to achieve stability -Ions are electrically charged atoms – ions have positive or negative charges because of an unequal number of protons and electrons – ionization is the process of losing or gaining electrons – this is symbolized by writing the chemical symbol, followed by the number of its (+) or (-) charges – so Ca2+ is a calcium ion that has 2 positive charges because it has lost two electrons / IONS ARE FORMED WHEN ATOMS LOSE OR GAIN ONE OR MORE VALENCE ELECTRONS (positively and negatively charged ions are attracted to each other) -A molecule is the combination of two or more atoms sharing electrons – a molecular formula indicates the elements and the number of atoms of each element that make up a molecule – a molecule can consist of two atoms of the same kind, like in oxygen (O2), - the ‘2’ indicating that the molecule contains two atoms of oxygen -A compound is a substance that contains atoms of two or more different elements –water (H20) and table salt (NaCl) are common compounds – oxygen (02) is not a compound because it consists of atoms of only one element 3. Explain, briefly, how ionic, covalent and hydrogen bonds are formed. -An ionic bond is the force of attraction that holds together ions with opposite charges (opposites attract) – in general, ionic compounds exist as solids, with an orderly, repeating arrangement of ions, such as a crystal of salt – a crystal of salt can be large or small – the number of ions can vary, but the ratio of Na(+) to Cl(-) is always 1:1 – an ionic compound that breaks apart into (+) and (-) ions in a solution is called an electrolyte – Below is a list of the names and symbols of common ions in the body -Below is how table salt is formed BOOM (ions and ionic bond formation) -When a covalent bond forms, two or more atoms share electrons rather than gaining or losing them (they can share 1, 2, or 3 pairs of valence electrons) – the larger number of electron pairs that are shared, the stronger the bond – covalent bonds can be formed between atoms of the same element (molecules) or of different elements (compounds) -A single covalent bond results when two atoms share 1 electron pair (like when a MOLECULE of hydrogen is formed by 2 hydrogen atoms sharing their single valence electrons) -A double covalent bond is formed when 2 atoms share 2 pairs of electrons (like in an oxygen molecule) -A triple covalent bond occurs with 2 atoms share 3 pairs of electrons (like a hydrogen molecule) -The same principles of covalent bonding that applies to atoms of the same element also apply to covalent bonds between atoms of different elements -A nonpolar covalent bond is when two atoms share the electrons equally – one atom does not attract the shared electrons more strongly than the other (the bonds between 2 identical atoms are always nonpolar covalent bonds) -In a polar covalent bond, the sharing of electrons between two atoms is unequal – the nucleus of one atom attracts the shared electrons more strongly than the other – when these bonds forms, the molecule has a partial negative charge near the atom that attract electrons more strongly (this atom has greater electronegativity; the power to attract electrons to itself) – and at least one other atom in the molecule with have a partial positive charge (these partial charges are indicated by a delta symbol followed by a + or -) -A hydrogen bond is made up from polar covalent bonds that form between hydrogen atoms and other atoms – a hydrogen bond forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of electronegative atoms – SOOO hydrogen bonds are formed by attracting oppositely charged parts of molecules, rather than sharing electrons like in covalent bonds or the loss or gain of electrons as in ionic bonds -Hydrogen bonds are weak compared to ionic/covalent bonds, and therefore cannot bind atoms into molecules 4. Define the term “chemical reaction,” and explain the basic differences between synthesis, decomposition, exchange and reversible reactions. -A chemical reaction occurs when new bonds form or old bonds break between atoms – the interactions of valence electrons are the basis of all chemical reactions – for instance, how hydrogen and oxygen molecules react to form water molecules (two H2 and one 02 are known as reactants, the ending substance; 2 molecules of H20 are the products) -The total mass of the reactants is the same as the total mass of the products (the atoms are just rearranged and therefore have different chemical properties) -Metabolism refers to all the chemical reactions occurring in the body -Synthesis reactions is when two or more atoms, ions or molecules combine to form new and larger molecules (synthesis = to put together) – a synthesis reaction can be explained as follows: an example can be the reaction between 2 hydrogen molecules and one oxygen molecule to form two molecules of water – all synthesis reactions that occur in the body are called anabolism (they are usually endergonic because they absorb more energy then they release) -Decomposition reactions split up large molecules into smaller atoms, ions, or molecules -Decomposition reactions that occur in the body are referred to as catabolism – they are usually exergonic because they release more energy than they absorb -Exchange reactions consist of both synthesis and decomposition – they work like the example below (the bonds between A and B and between C and D break, and new bonds then form between A and D and between B and C: AB + CD  AD + BC -Reversible reactions, the products can revert to the original reactants – these reactions are indicated by two half-arrows pointing in opposite directions -In the case where reactions are only reversible under special conditions, whatever is written above or below the arrows is indicates the condition needed for the reaction to occur, for example below – AB breaks down into A and B only when water is added. A and B react to produce AB only when heat is applied. 5. List and compare the properties of inorganic acids, bases, salts and water. -Inorganic compounds usually lack carbon and are structurally simple – their molecules only have a few atoms and they cannot perform complicated biological functions, they include water, many salts, acids and bases – they may have either ionic or covalent bonds – water makes up 55-60% of an adult’s body mass -Organic compounds always contain carbon, usually contain hydrogen, and always have covalent bonds – most are large molecules, and many are made up of long chains of carbon atoms – they make up 38-53% of the human body -Hydrophilic solutes are charged or contain polar covalent bonds, which means they dissolve easily in water – examples of this are sugar and salt -Hydrophobic molecules contain mainly nonpolar covalent bonds – they are not very soluble, examples include animal fats and vegetable oils -When a crystal of salt (NaCl) dissolves in water, the electronegative oxygen atom in water molecules attracts the sodium ions (Na+), and the electropositive hydrogen atoms in water molecules attract the chloride ions (Cl-) – soon water molecules surround and separate Na+ and Cl- ions from each other, breaking the bonds that held the NaCl together – the water molecules surrounding the ions also lessen the chance the Na+ and CL- will come together and re-form an ionic bond -Hydrolysis is the addition of water molecules to aid in breaking down molecules – hydrolysis reactions enable dietary nutrients to be absorbed into the body -Dehydration synthesis reaction: when two smaller molecules join to a larger molecule and a water molecule is one of the products formed -Water has a high heat capacity because it can absorb or release a large amount of heat with only a modest change in its own temperature – it has this capacity because of the large amount of hydrogen bonds in water – as water absorbs heat energy, some of the energy is used to break hydrogen bonds – less NRG is left over to increase the motion of H20 molecules, which would increase the temperature -Water is a major component of mucus and other lubricating fluids in the body when internal organs touch and slide over one another – it is also needed for joints, where bones, ligaments and tendons rub against one another – it also moistens food in the gastrointestinal tract to aid in digestion -A mixture is a combination of elements or compounds that are physically blended together but not bound by chemical bonds – like the air you are breathing, which is a mixture of gases – 3 common liquid mixtures are solutions, colloids and suspensions – once mixed together, solutes in a solution remain evenly spread among solvent molecules, and because solute particles are small, a solution looks transparent -A colloid has particles large enough to scatter in light (like how water droplets in fog scatter light from headlights) – for this reason, colloids usually appear translucent or opaque, like milk! It is both a colloid and a solution – the large milk proteins make it a colloid, whereas calcium salts, milk sugar (lactose), ions, and other particles are in solution -Solutes in both solutions and colloids do not settle out and accumulate at the bottom -In a suspension (by contrast), the suspended material might mix with the liquid or suspending medium for a moment, but it will eventually settle out (like blood) -Dissociation is when inorganic acids, bases, or salts dissolve in water (they separate into ions and become water molecules) -An acid is a substance that dissociates into 1 or more H ions (H+), and 1 or more anions – because H+ is a single proton with 1 positive charge, an acid is referred to as a proton donor -A base removes H+ form a solution and is therefore a proton acceptor -As seen in the picture below, many bases dissociate into 1 or more hydroxide ions (OH-) and 1 or more cations -A salt, when dissolved in water, dissociates into cations and anions, neither of which is H+ or OH- -In the body, salts (like potassium chloride) are electrolytes that are important for carrying electrical currents in nerve and muscular tissues -Acids and bases react with one another to form salts 6. Define the term “pH,” and explain the role of buffer systems in homeostasis. -To ensure homeostasis, intracellular and extracellular fluids must contain almost balanced quantities of acids and bases – the more hydrogen ions (H+) dissolved in a solution, the more acidic it is, whereas the more hydroxide ions (OH-), the more basic (alkaline) it is – any change from the narrow limits of normal H+ and OH- concentrations greatly disrupts bodily functions  -A solution’s acidity or alkalinity is rated on the pH scale (o-14) – a change of one whole number of the pH scale represents a tenfold change in the number of H+ (i.e. a pH of 6 denote 10x more H+ than a pH of 7) 7. Compare the structure and functions of carbohydrates, lipids, proteins, DNA, RNA and adenosine triphosphate (ATP). -Important categories of organic compounds include carbs, lipids, proteins, nucleic acids, and adenosine triphosphate (ATP) -Organic compounds are usually held together by covalent bonds – carbon has 4 electrons in its valence shell and can bond covalently to many atoms to form rings and straight or branched chains (C often bonds with H, 02 and N). -The chain of carbon atoms in an organic molecule is called the carbon skeleton – many of the C’s are bonded to H atoms, yielding hydrocarbon – also attached to the C skeleton are functional groups, which are atoms or molecules bound to the hydrocarbon skeleton Table 2.5 Major Functional Groups of Organic Molecules NAME AND STRUCTURAL FORMULA* OCCURRENCE AND SIGNIFICANCE Hydroxyl R­O­H Alcohols contain an ─OH group, which is polar and hydrophilic due to its electronegative O atom. Molecules with many ─OH groups dissolve easily in water. Sulfhydryl R­S­H Thiols have an ─SH group, which is polar and hydrophilic due to its electronegative S atom. Certain amino acids (for example, cysteine) contain ─SH groups, which help stabilize the shape of proteins. Carbonyl Ketones contain a carbonyl group within the carbon skeleton. The carbonyl group is polar and hydrophilic due to its electronegative O atom. Aldehydes have a carbonyl group at the end of the carbon skeleton. Carboxyl Carboxylic acids contain a carboxyl group at the end of the carbon skeleton. All amino acids have a ─COOH group at one end. The negatively charged form predominates at the pH of body cells and is hydrophilic. Ester Esters predominate in dietary fats and oils and also occur in our body as triglycerides. Aspirin is an ester of salicylic acid, a pain‐relieving molecule found in the bark of the willow tree. Phosphates Phosphates contain a phosphate group (─PO42−), which is very hydrophilic due to the dual negative charges. An important example is adenosine triphosphate (ATP), which transfers chemical energy between organic molecules during chemical reactions. Amino Amines have an ─NH2 group, which can act as a base and pick up a hydrogen ion, giving the amino group a positive charge. At the pH of body fluids, most amino groups have a charge of 1+. All amino acids have an amino group at one end. -Small organic molecules can combine into very large molecules called macromolecules – which are usually polymers -A polymer is a large molecule formed by the covalent bonding of many identical or similar building-block molecules called monomers – the reaction that joins two monomers together is a dehydration synthesis (an H atom is removed from one monomer and a hydroxyl group is removed from the other to form a molecule of water) -Molecules that have the same molecular formula but different structures are called isomers -Carbs include sugars, glycogen, starches and cellulose (making up only 2-3% of the body mass) – in humans and animals they mainly function to as a source of chemical energy for generating ATP, which is needed to drive metabolic reactions – only a few are used for building structural units, like deoxyribose (a type of sugar), which is used as a building block of DNA -Carbon, hydrogen and oxygen are the elements found in carbs – the ratio of H to oxygen atoms is usually 2:1 (the same as water) – the usually contain one water molecule for each carbon atom (this is why they are called carbs – carbohydrate means “watered carbon”) 1) monosaccharide’s – simple sugars – contain 3 – 7 carbon atoms -Glucose (blood sugar), fructose (fruits), galactose (milk), deoxyribose (DNA), ribose (RNA) -Their names end in -ose, and they have prefixes that indicate the number of carbon atoms, i.e. trioses, tetroses, pentoses, hexoses, and heptoses 2) disaccharides – simple sugars formed from the combo of 2 mono-‘s by dehydration synthesis -Sucrose (table sugar = glucose + fructose), lactose (milk sugar = glucose + galactose), maltose (glucose + glucose) -Below is an example of glucose and fructose combing by dehydration synthesis to form a molecule sucrose 3) polysaccharides – 10’s to 100’s of mono-s’s joined by dehydration synthesis -Glycogen (carbs in animals), starch (carbs in plants), cellulose (part of cells walls in plants) -They are usually insoluble in water and do not taste sweet – the main P in the human body is glycogen – made entirely of glucose monomers -Starches are P’s formed from glucose by plants -Liver cells break down glycogen into glucose and release it into the blood, making it available to body cells -Lipids are another group of organic compounds, which make up 18-25% of body mass in lean adults – like carbs, they contain C, H, and O2 – they do NOT have a 2:1 ratio of H to 02 – the amount of electronegative 02 atoms in lipids is usually smaller than in carbs, so there are fewer polar covalent bonds – for this reason, they are insoluble in polar solvents (like water) – they are hydrophobic – because of this, only the smallest lipids (some fatty acids) can dissolve in watery blood plasma – to become more soluble in blood plasma, other lipid molecules join hydrophilic proteins molecules – these lipid/protein complexes are called lipoproteins (they are soluble because the protein is on the outside and the lipids are on the inside) -Below are the various types of lipids: • Fatty acids: synthesize triglycerides and phospholipids, or catabolize to generate ATP • Triglyceride (fats and oils): protection, insulation, energy storage • Phospholipids: major component of cell membranes • Steroids: o Cholesterol – part of animal cell membranes, precursor of bile salts, vit D, and steroid hormones o Bile salts - needed for digestion and absorption of dietary lipids o Vitamin D – helps regulate calcium level in body o Adrenocortical hormones – helps regulate metabolism, resistance to stress, and salt/water balance o Sex hormones – stimulate reproductive functions/sex charact. • Eicosanoids: modify responses to hormones, blood clotting, inflammation, immunity, stomach acid secretion, airway diameter, lipid breakdown, and smooth muscle contraction • Other lipids: o Carotenes: needed for synthesis of vit A (used to make visual pigments in eye), function as antioxidants o Vitamin E – promotes mound healing, prevents tissue scarring, helps regulate structure and function of nervous system, antioxidant o Vitamin K – synthesis of blood-clotting proteins o Lipoproteins – transports lipids in blood, carry triglycerides and cholesterol to tissues and remove excess cholesterol from blood -Fatty acids are the simplest type of lipids – they synthesize triglycerides and phospholipids – they can also be catabolized to generate adenosine triphosphate (ATP) – it consists of a carboxyl group and a hydrocarbon chain – they can be saturated or unsaturated – a saturated fatty acid contains only single covalent bonds between the carbon atoms of the hydrocarbon chain – because they lack double bonds, each carbon atom of this hydrocarbon chain is saturated with hydrogen atoms. -An unsaturated fatty acid contains one or more double covalent bonds between the carbon atoms of the hydrocarbon chain (so it is not completely saturated with hydrogen atoms) – the unsaturated fatty acid has a kink at the site of the double bond – if it has just one double bound, it is monounsaturated, otherwise it is polyunsaturated -Triglycerides are most often found in the body and diet (also called triacylglycerol’s) – these consist of 2 types of building blocks, a single glycerol molecule and 3 fatty acid molecules. A 3-carbon glycerol molecule forms the backbone of a triglyceride – the 3 fatty acids are attached by dehydration synthesis reactions, one to each carbon of the glycerol backbone – the chemical bond formed where each water molecule is removed is an ester linkage (the reverse reaction, hydrolysis, breaks down a single molecule of a triglyceride into three fatty acids and a glycerol. - Shown in (a) are the structures of a saturated fatty acid and an unsaturated fatty acid. Each time a glycerol and a fatty acid are joined in dehydration synthesis (b), a molecule of water is removed. An ester linkage joins the glycerol to each of the three molecules of fatty acids, which vary in length and in number and location of double bonds between carbon atoms (C═C). Shown here (c) is a triglyceride molecule that contains two saturated fatty acids and a monounsaturated fatty acid. The kink (bend) in the oleic acid occurs at the double bond. -T’s can either be solid or liquid at room temperature – a fat is a T that is solid at room temp – the fatty acids of a fat are mostly saturated – because these saturated fatty acids lack double bonds in their hydrocarbon chains, they can closely pack together and solidify at room temperature (these are called saturated fats)!!! Saturated fats occur mostly in meats (mostly red meats), and non-skim dairy products (whole milk, cheese and butter) – they are also found in some plant products – cocoa butter, coconut oil and palm oil – too much of this can lead to heart disease and colorectal cancer -An oil is a T that is liquid at room temperature – the fatty acids are mostly unsaturated – they contain one or more double bonds in their hydrocarbon chains – the kinks at the site of the double bonds prevent the unsaturated fatty acids of the oil from closely packing together and solidifying – the fatty acids of an oil can either be monounsaturated or polyunsaturated -Monounsaturated fats contain T’s that mostly consist of monounsaturated fatty acids (olive oil, canola, peanut oil, nuts, avocados) -Polyunsaturated fats contain T’s that are mostly polyunsaturated fatty acids (corn oil, safflower oil, sunflower oil soybean oil, and fatty fish – salmon, tuna, mackerel) – both mono and poly unsaturated fats are believed to decrease the risk of heart disease – T’s are the body’s most highly concentrated form of chemical energy, they give you more energy (more than 2x) per gram as carbs and proteins -Essential fatty acids (EFA’s) are essential to human health, but cannot be produced by the human body – omega-3 fatty acids, omega-6 fatty acids and cis-fatty acids are quite important – omega 3 and 6 are polyunsaturated fatty acids lower cholesterol, raise HDL (high-density lipo-proteins or “good cholesterol”), and lowering LDL – they also decrease bone loss by increasing calcium utilization, reduce symptoms of arthritis due to inflammation, promote wound healing, improve certain skin disorders (psoriasis, eczema and acne) and improve mental functions -Omega 3  flaxseed, fatty fish, oils that have large amounts of polyunsaturated fatty acids, fish oils and walnuts -Omega 6  cereals, breads, white rice, eggs, baked goods, oils with large amounts of polyunsaturated fatty acids, and meats (organ meats like liver) -Cis-fatty acids  these are nutritionally beneficial unsaturated fatty acids used by the body to produce hormone-like regulators and cell membranes (the H atoms on either side of the double bond in oleic acid are on the same side of the unsaturated fatty acid) – HOWEVER, when heated, it is called hydrogenation – which changes it to an unhealthy trans-fatty acid (the H atoms are now on opposite sides of the double bond of an unsaturated fatty acid) – hydrogenated or trans-fatty acids = an increase total cholesterol, a decrease in HDL, increase in LDL, and an increase in T’s – which can increase the risk of heart disease, and other cardiovascular diseases (similar to the effects caused by saturated fats) -Phospholipids, like T’s, have a glycerol backbone and two fatty acid chains attached to the first two carbons – the head of a phospholipid is polar and can form H bonds with water molecules – the 2 fatty acids, or tails, are nonpolar and can interact only with other lipids – molecules that have both polar and nonpolar parts are amphipathic – amphipathic phospholipids line up tail-to-tail in a double row to make up the membrane that surrounds each cell -Steroids have 4 rings of carbon atoms – common steroids are cholesterol (cell membrane structure), estrogens, testosterone (regulating sexual functions), cortisol (blood sugar levels), bile salts (lipid digestion and absorption), and vitamin D (bone growth) are called sterols, because they have at least one hydroxyl (alcohol) group (-OH) – the polar –OH groups make sterols weakly amphipathic -All steroids have 4 carbon atoms (A, B, C and D) -Eicosanoids (another lipid) are lipids derived from a 20-carbon fatty acid called arachidonic acid – the 2 major subclasses are the prostaglandis (modify responses to hormones, contribute to inflammatory response, prevent stomach ulcers, dilate (enlarge) airways to the lungs, regulate body temp, help form blood clots, etc) and the lekuotrienes (allergic and inflamm response) -Proteins are large molecules that contain carbon, H, oxygen, and N (and some contain sulphur) – a lean body is 12 – 18% protein – they are largely responsible for the structure of body tissues – enzymes are proteins that speed up most biochemical reactions – other proteins drive muscle contractions – antibodies are proteins that protect against invading microbes -Different types of proteins have different functions: Structural Form structural framework of body parts, like collagen in bone and other connective tissue; keratin in skin, hair and fingernails Regulatory Function as hormones that regulate some physiological processes; control growth and development; work as neurotransmitters (i.e. to mediate sensation of pain in nervous system); mediate response of nervous system Contractile Allow shortening of muscle cells, which produces movement Immunological Aid responses that protect against foreign substances and invading pathogens, i.e. antibodies Transport Carry vital substances throughout body, i.e. haemoglobin –transports O2 and some C02 in blood Catalytic Act as enzymes that regulate biochemical reactions o -The monomers (molecules that can be bonded to other identical molecules to form a polymer) of proteins are amino acids – there are 20 different amino acids, all of which have an H atom and 3 functional groups attached to the central C atom - 8. Describe the characteristics of enzymes, and discuss their functions. Key Words and Topics Make certain that you can define, and use in context, each of the terms listed below, and that you understand the significance of each of the concepts. 1. Identify, by name and symbol, the principal chemical elements of the human body. o Chemical element o Chemical symbol 2. Describe the basic structure of an atom, ion, molecule, compound and free radical. o Atom • Nucleus • Proton • Neutron • Electron o Isotopes o Ion o Molecule o Compound o Free radical 3. Explain, briefly, how ionic, covalent and hydrogen bonds are formed. o Chemical bond • Valence shell of electrons • Ionic bond (see table) • Cation • Anion • Electrolyte • Covalent bond ▪ Polar ▪ Nonpolar • Hydrogen bond 4. Define the term “chemical reaction,” and explain the basic differences between synthesis, decomposition, exchange and reversible reactions. o Chemical reaction o Metabolism • Catalyst • Synthesis reaction (anabolism) • Decomposition reaction (catabolism) • Exchange reaction • Reversible reaction 5. List and compare the properties of inorganic acids, bases, salts and water. o Inorganic compound o Organic compound o Water as a solvent • Hydrophilic • Hydrophobic o Water in chemical reactions • Hydrolysis • Dehydration synthesis reaction o Heat capacity of water o Water as a lubricant o Mixture o Solution • Solvent • Solute o Acid • Hydrogen ion (H+) o Base • Hydroxide ion (OH-) o Salt 6. Define the term “pH,” and explain the role of buffer systems in homeostasis. o Acid-base balance • PH scale • Acidic solution • Basic solution or alkaline solution • Buffer system • Carbonic acid-bicarbonate buffer system 7. Compare the structure and functions of carbohydrates, lipids, proteins, DNA, RNA and adenosine triphosphate (ATP). o Organic compound o Carbohydrate (HOW MANY CARBONS ARE IN EACH CARBOHYDRATE) • Monosaccharide • Disaccharide • Polysaccharide • Glycogen o Lipid • Lipoprotein • Triglyceride or triacylglycerol • Glycerol • Fatty acid • Phospholipid • Steroid • Eicosanoids • Prostaglandins • Leukotrienes • Cholesterol o Protein • Functions of proteins - table • Amino acid • Peptide bond • Dipeptide, tripeptide, peptide, polypeptide • Primary structure, secondary structure, tertiary structure, quaternary structure • Denaturation o Nucleic acid • Deoxyribonucleic acid (DNA) • Ribonucleic acid (RNA) • Nucleotide • Nitrogenous base • Deoxyribose • Double helix • Ribose • Adenosine triphosphate (ATP) • Adenosine diphosphate (ADP) 8. Describe the characteristics of enzymes, and discuss their functions. o Enzyme o Substrate o Active site Read the “Chapter Review and Resource Summary” and work through the “Self-Quiz Questions” at the end of the chapter.