Flashcards
The Energy and Chemistry of Life
Flashcards do conjunto (66)
- 1The Chemistry of Energy and Life (Chapter 2)Chapter 2 / Exam 1
- 2Covalent Bondsform when two atoms share pairs of electrons.
The atoms attain stability by having full outer shells. - 3Strength and stabilitycovalent bonds are very strong; it takes a lot of energy to break them.
- 4Electronegativitythe attractive force that an atomic nucleus exerts on electrons.
- 5Non-Polar Covalent BondIf atoms have similar electronegativities (0.5 or less apart), they share electrons equally, forming
- 6Polar Covalent BondIf atoms have different electronegativities (more than 0.5 apart), electrons tend to be near the most attractive atom, forming a
- 7Hydrogen BondsAttraction between the δ– end of one molecule and the δ+ hydrogen end of another molecule.
- 8Heat 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.
- 9A lot of heat energy is required to raise the temperature of water, why ?the heat energy breaks the hydrogen bonds.
- 10Heat 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
- 11Evaporation has what type of affect?Cooling effect (on the environment)
- 12What does sweating do to the body?Sweating cools the body—as sweat evaporates from the skin, it absorbs some of the adjacent body heat.
- 13Cohesion (Hydrogen bonds give water cohesive strength)cohesion—water molecules resist coming apart when placed under tension
- 14AdhesionHydrogen bonding between liquid water molecules and solid surfaces allows for
- 15What do Cohesion and Adhesion allow in plants?(Cohesion and adhesion allow narrow columns of water to move from roots to the leaves of plants)
- 16Surface 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
- 17Hydrophillic(“water-loving”): in aqueous solutions, polar molecules become separated and surrounded by water molecules.
- 18Hydrophobic(“water-hating”); the interactions between them are hydrophobic interactions.
(Nonpolar) - 19Solvent (water is solvent in living systems)systems—a liquid in which other molecules dissolve.
(Ionic attractions are weak, so salts dissolve easily in water.) - 20What 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.
- 21Ions (result from transfer of electrons)electrically charged particles that form when atoms gain or lose one or more electrons.
- 22Cations and AnionsC: Positively charged ions
A: Negatively charged ions - 23Ionic Attractionsresult from the electrical attraction between ions with opposite charges. (The resulting molecules are called salts or ionic compounds.)
- 24Functional Groupsgroups—small groups of atoms with specific chemical properties
- 25ProteinsProteins—formed from different combinations of 20 amino acids
- 26CarbohydratesCarbohydrates—formed by linking sugar monomers (monosaccharides) to form polysaccharides
- 27Nucleic AcidsNucleic acids—formed from four kinds of nucleotide monomers
- 28LipidsLipids—noncovalent forces maintain the interactions between the lipid monomers
- 29Polymers (Most macromolecules)which are built by repeated covalent bonding of specific smaller molecules, called monomers.
- 30CondesationCondensation—removal of water links monomers together
- 31HydrolysisHydrolysis—addition of water breaks a polymer into monomers
- 32What are functions of Carbohydrates?- Source of stored energy
- Transport stored energy within organisms - 33What are the function of Carbohydrates? (ctn)- Structural molecules give many organisms their shapes
-Recognition or signaling molecules can trigger specific biological responses - 34MonosaccharidesSimple sugars
- 35DisaccharidesDisaccharides are formed when two monosaccharides are covalently bonded by condensation reactions
- 36Oglisaccharidescontain several monosaccharides.
(The human blood groups (ABO) get their specificity from oligosaccharide chains.) - 37Polysaccharidesare large polymers of monosaccharides connected by glycosidic likages, including starch, glycogen, and cellulose.
- 38Starchesbranched polymers of glucose, produced by most green plants as an energy store
- 39Glycogenhighly branched polymer of glucose; main energy storage molecule in mammals
- 40Lipidscommonly called fats and oils, are hydrocarbons (composed of C and H atoms) that are insoluble in water because of many nonpolar covalent bonds.
- 41What holds lipids together?When close together, weak but additive van der Waals interactions hold them together.
- 42What 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 - 43Fatty AcidsFatty acids—nonpolar hydrocarbon chain attached to a polar carboxyl group (—COOH) (carboxylic acid)
- 44Glycerol(one) - glycerol—an alcohol with three hydroxyl (—OH) groups
- 45Triglyceridethree fatty acids and one glycerol
- 46Saturated Fatty Acidsall bonds between carbon atoms are single; they are saturated with hydrogens
(Fats—solid at room temperature) - 47Unsaturated Fatty Acidshydrocarbon 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) - 48Trigylcerides(simple lipids) are insoluble in water because of many nonpolar covalent bonds (C-H).
Have very little polarity and are extremely hydrophobic - 49Phospholipidstwo fatty acids and a phosphate group bound to glycerol.
(The phosphate group has a negative charge, making that part of the molecule hydrophilic.) - 50Amphipathic (Phospholipids are amphi..)they have a hydrophilic end and two hydrophobic tails.
- 51Chemical Reactionsoccur when atoms have enough energy to combine or change bonding partners
- 52Energycan be defined as the capacity to do work, or the capacity for change. All forms of energy can be considered as either
- 53Potential EnergyPotential—the energy of state or position, or stored energy
- 54KineticKinetic—the energy of movement; the type of energy that does work; that makes things change
- 55MetabolismMetabolism—sum total of all chemical reactions occurring in a biological system at a given time
- 56What are the 2 types of metabolisms?Anabolic reactions & catabolic reactions
- 57Anabolic reactionsAnabolic reactions link simple molecules to form complex ones.
- 58What 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.
- 59Catabolic reactionsbreak down complex molecules into simpler ones
- 60What do catabolic reactions do?They release energy (exergonic or exothermic); can occur spontaneously. Energy stored in the chemical bonds is released.
- 61Catabolic and anabolic reactions are often linked, why?The energy released in catabolic reactions is often used to drive anabolic reactions—to do biological work.
- 62Law of Thermodynamicsapply to all matter and energy transformations in the universe.
- 63First Law (Law of Thermodynamics)Energy is neither created or destroyed
- 64Second Law (Law of Thermodynamics)Second law: Useful energy tends to decrease.
- 65Entropyis 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. - 66done:):)
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- This is from a ppt, bio 196 in college. Chapter 2 of principles of life.
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