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biol exam 2
ch. 6 notes; ch. 7 notes; online quiz; lab hw6
| Question | Answer |
|---|---|
| ___ is anything that takes up space and has mass- the physical material of the universe | matter |
| What are the two major categories of energy? | Potential and kinetic energy |
| ____ energy is energy stored in matter because of its position or location | potential |
| ____ energy is the energy of motion | kinetic |
| Potential energy in biological systems can be stored in ___ ____ | chemical bonds |
| The Laws of Thermodynamics describes the Properties of _____ | energy |
| First Law of Thermodynamics which states that energy can be transferred and transformed, but it cannot be _____ or _____ (i.e., the energy of the universe is constant). | created or destroyed |
| Second Law of Thermodynamics which states that every energy transfer or transformation makes the _____ more ______ (i.e., every process increases entropy at the cost of useful energy) | universe more disordered |
| What is an example of the first law of thermodynamics? | the energy of the universe is constant |
| what is an example of the second law of thermodynamics? | every process increases entropy at the cost of useful energy |
| a ____ ____ is a system which is completely isolated from its surroundings | closed system |
| in an ____ ____ energy can be transferred between the system and the surroundings | open system |
| In all chemical reactions you begin with one set of substances, _______, and end with a different set of substances, _______. | reactants; products |
| _____determines whether or not a chemical reaction will occur in the cell, and how much energy it will consume or release | thermodynamics |
| Chemical reactions are either _____ or ______ | exergonic or endergonic |
| _____ reactions are reactions that release energy | exergonic |
| ______ reactions are energy-requiring reactions | endergonic |
| In exergonic reactions they _____ energy, the reaction is energetically _____, they are _______ reactions | release; downhill; spontaneous |
| In endergonic reactions they _____ energy, the reaction is energetically _____, they are _______ reactions (requires an energy source) | requires; uphill; non-spontaneous |
| Although exergonic reactions release energy overall, they may require some energy to get them started. This "started energy" is called _____ _____ | activation energy |
| ____ _____ is the amount of energy that reactant molecules must absorb to start a reaction | activation energy |
| Chemical reactions which release energy can be coupled to chemical reactions which take energy. What would be an example of this? | sun and plants- photosynthesis |
| Chemical reactions are reversible and will reach a ____ _____ | chemical equilibrium |
| ____ _____ is the equilibrium reached when the rare of the forward reaction is equal to the rate of the reverse reaction. *(this does not mean that the concentration of reactants and products are equal)* | chemical equilibrium |
| _____ is the totality of an organism's chemical processes | metabolism |
| Metabolism consists of 1)____ of matter and energy 2)____ to usable form 3)_____ of cellular materials 4)_____ of waste products | uptake; conversion; synthesis; elimination |
| The chemistry of life is organized into _____ pathways | metabolic |
| What are the 2 types of metabolic pathways? | catabolic and anabolic pathways |
| _____ _____ are metabolic pathways which release energy by breaking down complex molecules to simpler compounds | catabolic pathways |
| catabolic pathways are metabolic pathways which ____ energy by breaking down _____ ____ to ____ _____ | release; complex molecules; simpler compounds |
| ____ _____ are metabolic pathways which consume energy to build complicated molecules from simpler ones | Anabolic pathways |
| Degradation means it ___ ____ | releases energy |
| Synthesis means it is ____ ____ | energy requiring |
| ____ speed up metabolic reactions by lowering energy barriers | enzymes |
| ____ are chemical agents that accelerated a reaction without being permanently changed in the process | catalysts |
| a catalyst is ____ and is not _____ by the reaction | reusable; destroyed |
| _____ are biological catalysts which are usually proteins | enzymes |
| enzymes are biological catalysts which are usually ____ | proteins |
| ____ are substrate-specific | enzymes |
| _____ are the substances which enzymes act on. In the presence of the appropriate enzyme, the ______ become more reactive | substrates; substrates |
| An enzyme binds to its ____ and _______ the conversion of the substrate (reactants) to the product. The enzyme is ____ by the process. | substrate; catalyzes; unchanged |
| The substrate binds to the ___ ____ of an enzyme | actives site |
| _____ _____ is the restricted region of an enzyme molecule where the substrate is bound | active site |
| The ___ ____ is usually a pocket or groove on the surface of the protein | active site |
| the active site is usually a pocket or groove on the surface of the ____ | protein |
| The active site is usually formed by only a few _____ ____ ____ | amino; acid; r-groups |
| The shape, size, and binding ability of the active site are ____-_____ | substrate-specific |
| Some enzymes require ____ to function | coenzymes |
| _____ are small non-protein organic molecules that are required for proper enzyme catalysis (e.g., vitamins) | coenzymes |
| whats an example of a coenzyme? | vitamins |
| Metabolic pathways are regulated by controlling enzyme ____ and ____ | synthesis and activity |
| ____ ____ is the regulation of a metabolic pathway by its end product, which inhibits an enzyme within the pathway | feedback inhibition |
| Feedback inhibition usually occurs a ____-____ or at a ____ ___. Feedback inhibition also ____ the cell from making something it has enough of already | branch-point; committed step; prevents |
| ____ _____ are specific receptor sites on some part of the enzyme molecules other than the active site. When the non-competitive inhibitor binds, it changes the active site indirectly | allosteric sites |
| ____ _____ are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site | competitive inhibitors |
| Almost all organism obtain their energy from the _____ (directly or indirectly) | sun |
| _______-solar energy is trapped and stored as chemical energy in the bonds of organic molecules | photosythesis |
| synthesis of energy-rich organic molecules (______) from energy-poor molecules (____ and ____) occurs during photosynthesis | glucose; CO2 and H2O |
| Photosynthesis uses ___ as a carbon source and ____-_____ as the energy source | CO2; light-energy |
| _____ are the site of photosynthesis in plants | chloroplasts |
| _____ are the major organs of photosynthesis | leaves |
| ______ is the green pigment that gives a leaf its color. Also, it is responsible for the absorption of the light energy that drives photosynthesis | chlorophyll |
| Chloroplasts are primarily in cells of _____(in the leaf interior) | mesophyll |
| CO2 and H2O enter the leaf through pores called ______ | stomata |
| Water is absorbed by the roots and transported to the leaves through the _____ _____ | vascular bundles |
| _____ contain the thylakoids and the stroma | chloroplasts |
| _____ are flattened membranous sacs inside the chloroplast | thylakoids |
| chlorophyll is located in the ____ _____ | thylakoid membrane |
| The thylakoids are arranged in stacks called ____ | grana |
| the thylakoids are where _____-______ reactions occur | light-dependent |
| ____ are stacks of thylakoids in a chloroplast | grana |
| ______-_____ reaction is the reaction of photosynthesis that converts light energy to chemical bond energy in ATP and NADPH | light-dependent |
| light-dependent reaction is the reaction of photosynthesis that converts light energy to chemical bond energy in ____ and _____ | ATP and NADPH |
| The second law of thermodynamics essentially says | entropy increases |
| The energy required to destabilize existing chemical bonds is called ____ energy. | activation |
| If DG is said to be positive, it means | products of the reaction contain more energy than the reactants |
| Which of the following is uncharacteristic of ATP? | It is a good long-term energy storage molecule. |
| The most primitive form of metabolism is | the degradation of organic molecules with the released energy stored in ATP (The earliest organisms degraded organic molecules from an abiotic source for energy, which they stored in ATP.) |
| The First Law of Thermodynamics states that energy can be | converted |
| The universal energy currency for all cells is | ATP |
| Enzymes... | lower the activation energy of a reaction |
| To what category of macromolecules do most enzymes belong? | proteins |
| NAD+ is a(n) | coenzyme |
| Which of the following is a reduced compound? A)CO2 B)O2 C)N2 D)NAD+ E)NADH | E) NADH |
| In an endergonic reaction, | the reactants contain less free energy than the products |
| The energy of random molecular motion is called | heat |
| The energy available to do work in a system is called | free energy |
| The initial steps in breaking down glucose are called | glycolysis |
| A catalyst will make a reaction.. | speed up |
| When molecules are reduced they gain | energy, electrons, and hydrogen protons |
| Which of the following statements about enzymes is true?A)some substrates can make enzymes change shape slightlyB)all enzymes have the same pH optimumC)the active sites of all enzymes have the same three-dimensional shape | A) some substrates can make enzymes change shape slightly |
| Cofactors... | help facilitate enzyme activity |
| How much energy is released when one of the high-energy bonds in ATP is broken? | 7.3 kcal/mole |
| Consider the hypothetical biochemical pathway H -- I -- J-- K-- L. Which step most likely evolved first? | K--L |
| Why do drastic changes in the temperature or pH of a system alter enzyme activity?A)they change the three-dimensional shape of theB)they disrupt hydrogen and ionic bonds in the enzymeCthey disrupt hydrophobic interactions in the enzymeD)all of the above | D) all of the above |
| The loss of an electron by a molecule is called | oxidation |
| In the chemical equation G = H - TS, the term G stands for | free energy |
| Enzyme B requires Zn2+ in order to catalyze the conversion of substrate X. The zinc is best identified as a(n): | cofactor |
| chemical reaction that is catalyzed by the enzyme malic dehydrogenase: malic acid + NAD+ -----> oxaloacetic acid + NADH + H+ delta G = +7.1 kcal. NAD+ is.... | being reduced, a coenzyme, and an oxidizing agent |
| chemical reaction that is catalyzed by the enzyme malic dehydrogenase: malic acid + NAD+ -----> oxaloacetic acid + NADH + H+ delta G = +7.1 kcal. NAD+ is a reducing agent, true or false? | false |
| What must be true for a reaction to occur spontaneously? | delta G must be negative |
| Redox reaction (oxidation-reduction) involve... | the loss of electrons termed oxidation |
| The actions of an enzyme can be affected by all of the following except A)p/PH B)temperature C)allosteric inhibitors D)availability ATP E)cofactors | D)availability ATP |
| Which of the following are mismatched A)anabolic reactions-expend energy B)reduction-gain of an electron C)endergonic reaction-anabolism D)exergonic reaction-catabolism E)activation energy-entropy | E)activation energy-entropy |
| Energy is the capacity to cause change. ____ energy is the energy associated with motion. Energy that is not ___ is called ___ energy, and is energy that matter possesses because of its location or structure. | kinetic; kinetic; potential |
| Energy is neither created nor destroyed but ____ from one form to another. this property is called the _____ of energy | converted; conservation |
| The bow and arrow start out with low ___ energy. As the archer's arm pulls back the string, ___ energy from the arm's motion is converted to ___ energy in the tense bowstring and arrow. | potential; kinetic; potential |
| When the bowstring is released, the stored ____ energy is converted into the ___ energy of the moving arrow. | potential; kinetic |
| When energy is converted from potential energy to kinetic energy, some of the energy can be used to do ____, but some energy ends up as ____, a type of kinetic energy. ____ is the random motion of atoms and molecules. | work; heat; heat |
| ____ energy is a very disordered kind of energy. It has the highest amount of ____, or disorder, of any kind of energy | heat; entropy |
| a quantitative measure of disorder or randomness, symbolized by S | entropy |
| Our bodies use the ____ energy from food to perform work. ___ energy is a form of potential energy.When your body breaks down food molecules, the stored potential energy from food can be converted to kinetic energy | chemical; chemical |
| The stored chemical energy in food is released in your muscle cells during the process of ___ ___. Using oxygen, ___ ____ converts chemical energy from food to another form of chemical energy called ATP. | cellular respiration; cellular respiration |
| ____(___) and ___ ____(___) are by-products of cellular respiration | water(H2O); carbon dioxide(CO2) |
| energy cannot be created or destroyed but can be converted from one form to another refers to the ____ of ____ | conservation of energy |
| Chemical energy is a form of _____ energy | potential |
| In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? | cellular respiration |
| Heat, carbon dioxide, and water are the by-products of what? | cellular respiration |
| Imagine a candy bar sitting on a table in front of you. Which specific types of energy are present in the candy bar? | heat, chemical, and positional energy |
| ____ reactions require an input of energy, so the products have more energy than the reactants used to create them. | endergonic |
| Plants use sunlight to convert carbon dioxide and water into sugar and oxygen. What is the sunlight providing to the equation? | kinetic energy |
| ___ powers nearly all forms of cellular work by providing energy stored in its chemical bonds. | ATP |
| During cellular respiration, ___ releases energy. This energy is stored when a phosphate group is added to ADP (adenosine diphosphate), forming ATP (adenosine triphosphate). | glucose |
| During cellular respiration, glucose releases energy. This energy is stored when a phosphate group is added to ___, forming ____ | ADP; ATP |
| ____releases energy when the covalent bond between phosphate groups breaks during hydrolysis. This energy is used to drive other biochemical reactions. | ATP |
| ATP releases energy when the ___ bond between ___ groups breaks during hydrolysis. This energy is used to drive other biochemical reactions. | covalent; phosphate |
| What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule? | hydrolysis |
| ___involves breaking bonds with the addition of water | hydrolysis |
| In a ___reaction, an exergonic reaction provides energy to run an endergonic reaction. | coupled |
| In a coupled reaction, an ___reaction provides energy to run an ___reaction. | exergonic; endergonic |
| Life uses many ___reactions to perform endergonic reactions, such as building proteins from amino acids or charging up ATP. | coupled |
| Connecting ADP and P is ____, breaking ATP apart into ADP and P is ____. | endergonic; exergonic |
| The enzyme amylase in human saliva breaks ___polymers down into smaller sugar units. However, it cannot break down __polymers. Both are made of glucose monomers, but in ___the monomers are linked together in a different shape than ___. | starch; cellulose; cellulose; starch |
| amylase cant digest cellulose because the bonds of ____ do not fit properly in the active site | cellulose |
| ____lower the activation energy of an exergonic reaction. | catalysts |
| Catalysts lower the activation energy of an ____ reaction | exergonic |
| Catalysts lower the ____ energy of an exergonic reaction | activation |
| The energy needed to start a chemical reaction is called the ___of ___(EA). This required energy input represents a barrier that prevents even energy-releasing exergonic reactions from occurring without some added energy. | energy of activation |
| The energy needed to start a chemical reaction is called the energy of activation (EA). This required energy input represents a barrier that prevents even energy-releasing ____ reactions from occurring without some added energy. | exergonic |
| How does a living cell overcome the energy barrier so that its metabolic reactions can occur quickly and precisely? A special kind of protein called an ____ is the answer. | enzyme |
| An ___ serves as a biological catalyst, increasing the rate of a reaction without being changed into a different molecule. An ____ does not add energy to a reaction; instead, it speeds up a reaction by lowering the energy barrier. | enzyme; enzyme |
| An enzyme is very selective. Its three-dimensional shape allows it to act only on specific molecules, referred to as the enzyme's _____. | substrates |
| As the substrates bind to the enzyme's active site, they are held in a position that facilitates the reaction. This takes less activation energy than the unaided reaction. Products form and are released. The enzyme emerges ____ from the reaction. | unchanged |
| Because of the specific fit between enzyme and substrate, each enzyme can catalyze only one kind of reaction involving specific substrates. Thousands of different enzymes may be required to carry out all of a cell's ____ processes. | metabolic |
| most enzymes are ____ | proteins |
| enzymes work by reducing ____ energy | activation |
| an enzyme is an organic ___ | catalyst |
| enzymes are proteins that behave as ____ | catalysts |
| What name is given to the reactants in an enzymatically catalyzed reaction? | substrate |
| As a result of its involvement in a reaction, an enzyme is ____ | unchanged |
| Enzymes are not ____as a result of their participation in a reaction | changed |
| The energy of ___ must be overcome in order for a reaction to proceed. | activation |
| A physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change. | positive feedback |
| In ____feedback, a product of the reaction sequence enhances the action of one of the enzymes, increasing the rate of production of the product | positive |
| ____feedback is less common than ____feedback in living systems. | positive; negative |
| in ____ feedback, the end product of a reaction sequence shuts down the reaction sequence | negative |
| _____ inhibitors stop a chemical reaction when they bind in the active site of an enzyme | competitive |
Created by:
kenzey11