3511100
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Flashcards by jensha21285, updated more than 1 year ago
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Created by jensha21285
over 9 years ago
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| Question | Answer |
| The Chemistry of Energy and Life (Chapter 2) | Chapter 2 / Exam 1 |
| Covalent Bonds | form when two atoms share pairs of electrons. The atoms attain stability by having full outer shells. |
| Strength and stability | covalent bonds are very strong; it takes a lot of energy to break them. |
| Electronegativity | the attractive force that an atomic nucleus exerts on electrons. |
| Non-Polar Covalent Bond | If atoms have similar electronegativities (0.5 or less apart), they share electrons equally, forming |
| Polar Covalent Bond | If atoms have different electronegativities (more than 0.5 apart), electrons tend to be near the most attractive atom, forming a |
| Hydrogen Bonds | Attraction between the δ– end of one molecule and the δ+ hydrogen end of another molecule. |
| Heat Capacity (water molecules form multiple hydrogen bonds which contribute to HC) | is the amount of heat required to raise the temperature of an object or substance one degree. |
| A lot of heat energy is required to raise the temperature of water, why ? | the heat energy breaks the hydrogen bonds. |
| Heat Vaporization (water has high HV) | is the quantity of heat that must be absorbed if a certain quantity of liquid is vaporized at a constant temperature |
| Evaporation has what type of affect? | Cooling effect (on the environment) |
| What does sweating do to the body? | Sweating cools the body—as sweat evaporates from the skin, it absorbs some of the adjacent body heat. |
| Cohesion (Hydrogen bonds give water cohesive strength) | cohesion—water molecules resist coming apart when placed under tension |
| Adhesion | Hydrogen bonding between liquid water molecules and solid surfaces allows for |
| What do Cohesion and Adhesion allow in plants? | (Cohesion and adhesion allow narrow columns of water to move from roots to the leaves of plants) |
| Surface Tension (Which allows spiders to walk on water) | water molecules at the surface are hydrogen-bonded to other molecules below them, making the surface difficult to puncture |
| Hydrophillic | (“water-loving”): in aqueous solutions, polar molecules become separated and surrounded by water molecules. |
| Hydrophobic | (“water-hating”); the interactions between them are hydrophobic interactions. (Nonpolar) |
| Solvent (water is solvent in living systems) | systems—a liquid in which other molecules dissolve. (Ionic attractions are weak, so salts dissolve easily in water.) |
| What happens when one atoms is much more electronegative than another? | a complete transfer of electrons may occur. This makes both atoms more stable because their outer shells are full. |
| Ions (result from transfer of electrons) | electrically charged particles that form when atoms gain or lose one or more electrons. |
| Cations and Anions | C: Positively charged ions A: Negatively charged ions |
| Ionic Attractions | result from the electrical attraction between ions with opposite charges. (The resulting molecules are called salts or ionic compounds.) |
| Functional Groups | groups—small groups of atoms with specific chemical properties |
| Proteins | Proteins—formed from different combinations of 20 amino acids |
| Carbohydrates | Carbohydrates—formed by linking sugar monomers (monosaccharides) to form polysaccharides |
| Nucleic Acids | Nucleic acids—formed from four kinds of nucleotide monomers |
| Lipids | Lipids—noncovalent forces maintain the interactions between the lipid monomers |
| Polymers (Most macromolecules) | which are built by repeated covalent bonding of specific smaller molecules, called monomers. |
| Condesation | Condensation—removal of water links monomers together |
| Hydrolysis | Hydrolysis—addition of water breaks a polymer into monomers |
| What are functions of Carbohydrates? | - Source of stored energy - Transport stored energy within organisms |
| What are the function of Carbohydrates? (ctn) | - Structural molecules give many organisms their shapes -Recognition or signaling molecules can trigger specific biological responses |
| Monosaccharides | Simple sugars |
| Disaccharides | Disaccharides are formed when two monosaccharides are covalently bonded by condensation reactions |
| Oglisaccharides | contain several monosaccharides. (The human blood groups (ABO) get their specificity from oligosaccharide chains.) |
| Polysaccharides | are large polymers of monosaccharides connected by glycosidic likages, including starch, glycogen, and cellulose. |
| Starches | branched polymers of glucose, produced by most green plants as an energy store |
| Glycogen | highly branched polymer of glucose; main energy storage molecule in mammals |
| Lipids | commonly called fats and oils, are hydrocarbons (composed of C and H atoms) that are insoluble in water because of many nonpolar covalent bonds. |
| What holds lipids together? | When close together, weak but additive van der Waals interactions hold them together. |
| What are some functions of Lipids? | Store energy in C—C and C—H bonds Play structural roles in cell membranes Fat in animal bodies serves as thermal insulation |
| Fatty Acids | Fatty acids—nonpolar hydrocarbon chain attached to a polar carboxyl group (—COOH) (carboxylic acid) |
| Glycerol | (one) - glycerol—an alcohol with three hydroxyl (—OH) groups |
| Triglyceride | three fatty acids and one glycerol |
| Saturated Fatty Acids | all bonds between carbon atoms are single; they are saturated with hydrogens (Fats—solid at room temperature) |
| Unsaturated Fatty Acids | hydrocarbon chains have one or more double bonds. This causes kinks in the chain and prevents molecules from packing together tightly. (Oils—liquid at room temperature) |
| Trigylcerides | (simple lipids) are insoluble in water because of many nonpolar covalent bonds (C-H). Have very little polarity and are extremely hydrophobic |
| Phospholipids | two fatty acids and a phosphate group bound to glycerol. (The phosphate group has a negative charge, making that part of the molecule hydrophilic.) |
| Amphipathic (Phospholipids are amphi..) | they have a hydrophilic end and two hydrophobic tails. |
| Chemical Reactions | occur when atoms have enough energy to combine or change bonding partners |
| Energy | can be defined as the capacity to do work, or the capacity for change. All forms of energy can be considered as either |
| Potential Energy | Potential—the energy of state or position, or stored energy |
| Kinetic | Kinetic—the energy of movement; the type of energy that does work; that makes things change |
| Metabolism | Metabolism—sum total of all chemical reactions occurring in a biological system at a given time |
| What are the 2 types of metabolisms? | Anabolic reactions & catabolic reactions |
| Anabolic reactions | Anabolic reactions link simple molecules to form complex ones. |
| What do anabolic reactions require? | They require energy inputs (endergonic or endothermic); usually doesn’t occur spontaneously. Energy is captured in the chemical bonds that form. |
| Catabolic reactions | break down complex molecules into simpler ones |
| What do catabolic reactions do? | They release energy (exergonic or exothermic); can occur spontaneously. Energy stored in the chemical bonds is released. |
| Catabolic and anabolic reactions are often linked, why? | The energy released in catabolic reactions is often used to drive anabolic reactions—to do biological work. |
| Law of Thermodynamics | apply to all matter and energy transformations in the universe. |
| First Law (Law of Thermodynamics) | Energy is neither created or destroyed |
| Second Law (Law of Thermodynamics) | Second law: Useful energy tends to decrease. |
| Entropy | is a measure of the disorder in a system. As a result of energy transformations, disorder tends to increase. If a chemical reaction increases entropy, its products are more disordered or random than its reactants. |
| done:) | :) |
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