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The energy in a system that can be used to do work or promote change is known as __________ energy.
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All living things require which of the following in order to carry out chemical reactions?
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Biology
Chaper 6
| Question | Answer |
|---|---|
| The energy in a system that can be used to do work or promote change is known as __________ energy. | free |
| All living things require which of the following in order to carry out chemical reactions? | energy |
| These statements are true of exergonic reactions. | 1. Exergonic reactions are spontaneous 2. Exergonic reactions release energy during product formation |
| A fraction of the energy from the sun is captured by plants, algae, and some bacteria through the process of _________. | photosynthesis |
| In the following chemical reaction, which molecule(s) is(are) reduced? Ac- +B-> A+ Be- | B |
| __________ are small chemical components usually inorganic ions, such as Zn, Cu, and Mn, that temporarily attach to the surface of an enzyme and promote a chemical reaction. | cofactors |
| Which of the following occurs during the reduction of an atom or molecule? | 1. The net charge of the atom or molecule decreases due to addition of a negatively charged electrons. 2. One or more electrons are added to the atom or molecule |
| Energy can exist in two states: ________ energy and ________ energy | Kinetic, potential |
| Is any energy released during ATP hydrolysis and if so, how much? | A considerable amount of energy is released |
| What is the function of catabolic reactions? | Catabolic pathways are involved in the breakdown of larger molecules into smaller ones. |
| Cells use _______ hydrolysis to drive endergonic reactions. | ATP |
| Which of the following statements are true about chemical reactants? | 1. A reaction that is exergonic in the forwards direction will endergonic in the reverse direction. 2.Chemical reactions are reversible |
| The order of enzyme catalysis. | 1. Substrate binds to enzyme. 2. Substrate-enzyme complex is formed. 3. Amino acids from enzyme interact with substrate 4. Bonds in substrates are broken and/or created; product form 5. Products dissociate from the enzyme |
| What happens if a chemical substance binds to an enzyme and alters its shape? | 1. The enzyme's activity can be increased. 2. The enzyme's activity can be decreased. |
| What is the description of a coenzyme? | Organic molecules that temporarily attach to an enzyme and promote chemical reaction without being changed during the reaction |
| What of the following is true about the regulation of enzyme activity in cells? | Cells can regulate the activity of enzyme by inhibiting or activating them. |
| What about endergonic reactions it true. | 1. The products have a higher free energy than the reactants. 2. Endergonic reactions have a positive change in free energy. 3. Endergonic reactions require the addition of free energy. 4. Endergonic reactions are not spontaneous. |
| How can the functioning of an enzyme be affected by the external environment? | 1. Altering the pH can be harmful to an enzyme when the pH is outside the normal or optimal range for that enzyme. 2.Increasing temperature can greatly affect the function of some enzyme by causing denaturation. |
| Differences between anabolic and catabolic reactions. | 1. In catabolic reactions large molecule are broken down, while in anabolic reactions large molecules are made from smaller ones. 2. Catabolic reactions release energy, while anabolic reaction need energy input. |
| The general term for all types of coordinated sequences of chemical reactions in organisms is which of the following? | Metabolic and Biochemical |
| Multienzyme complexes improve catalytic efficiency. | 1. The product of one reaction can be delivered to the next enzyme more easily. 2. Because products do not leave the complex, there are no unwanted side reactions. 3. All of the reactions inside the complex can be controlled as one unit. |
| Why changes in the pH of the fluid in which an enzyme is dissolved affect the enzyme's ability to function. | 1. Enzymes cannot maintain their three-dimensional shape. 2. The balance between positively and negatively charged amino acids in the enzyme is shifted. |
| What about enzymes are NOT true? | 1. All enzyme are proteins. 2. All enzymes are attached to membranes. 3. Most enzymes are proteins, In addition some DNA molecules can act as enzyme in the nucleus |
| Statements about ribozymes. | 1. Similar to protein enzymes, ribozymes can greatly accelerate the rate of a reaction. 2. Similar to protein enzymes, ribozymes show high substrate specific. |
| Statements about allosteric sites on enzymes. | 1. This is where a non- competitive inhibitor would bind. 2. The bonding of a substance to the allosteric site can both turn on and turn off an enzyme. |
| Why do catalysts increase the rate of a chemical reaction? | Catalysts stress bonds, making them easier to break and lowering activation energy. |
| When a physical system becomes more disordered, the entropy ________. | Increases |
| What is an example of an object with high potential energy? | Water stored in a reservoir behind a dam. |
| What is allosteric inhibitor? | A molecule that binds to the site other than the active site of an enzyme and inhibits the enzyme's function. |
| When a reactant binds to the active site of an enzyme, this produces the _________ - __________ complex. | enzyme-substrate |
| In chemical reactants, ________ refers to the process when one or more electrons are added to a molecule or atom. | reduction |
| Any substance that influence chemical bonds in such a way, that the activation energy of a reaction is lowered, is known as a _________. | catalyst |
| What cofactors that are called coenzymes: | Vitamin B12 and Vitamin B6 |
| During chemical reaction, which molecules become oxidized? | Molecules that have an electron removed |
| An important characteristic of biological catalysts which distinguishes them from chemical catalysts is their _________ which refers to the fact that each enzyme can usually speed up only one or a few similar reactions | specificity |
| Work in the cell or in the physical world can only be done with expenditure of __________; it is defined as the capacity to do work. | energy |
| Redox reaction is a term used to describe an _________ - _______ reaction | oxidation reduction |
| What type of reactions are involved in the synthesis of larger molecules from smaller molecules | Anabolic |
| Chemical reactions are _________ which means that they can proceed in either direction ( reactants to products or products to reactants) | reversible |
| How is metabolism described? | Metabolism refers to the sum of all chemical reactions that occur within an organism |
| During the breakdown of small organic molecules, oxidation occurs when? | Electrons are removed from an atom or molecule |
| Which of the following is the branch of chemistry concerned with energy changes? 1. Inorganic chemistry 2. Thermodynamics 3. Organic chemistry 4. Cytochemistry | Thermodynamics |
| All energy that enters biological systems ultimately comes from the _______. | Sun |
| (Catabolic or anabolic) Cells harvest energy during _________ reactions and expend energy during _______ reaction. | Catabolic and anabolic |
| __________ stored in chemical bonds of a molecule can be used to make new bonds in a different molecule. | Energy |
| Heat is a measure of the random motion of molecules a form of _______ energy | Kinetic |
| What is true about oxidized molecules? | They have less electrons and less energy than reduced molecules |
| All cells us molecules called ________ to store and release energy cyclically. | ATP |
| What are small chemicals, usually inorganic ions, that temporarily attach to the surface of an enzyme and promote a chemical reaction? | cofactors |
| _________ energy is a form of potential energy stored within the covalent bonds of molecules. | Chemical |
| A reaction is said to be ____________ when the addition of free energy from the environment is required for the reaction to proceed. | endergonic |
| Exergonic reactions have a(n) _________ charge in free energy, and endergonic reactions have a(n) ________ charge in free energy. | Negative and positive |
| How much energy is released when the outermost phosphate bond of ATP is hydrolyzed under standard conditions? | 7.3 kcal/mol |
| Increasing the temperature outside the optimal range for an enzyme can lead to ___________ of the enzyme, altering the enzyme's structure and function. | denaturation |
| What is true about spontaneous energy transformation? | They proceed to convert matter from a more ordered to less ordered form |
| All chemical reactions, even exergonic ones require __________ to destabilize existing chemical bonds and initiate a chemical reaction. | Activation energy |
| What organic molecules can accept electrons from the active site of one enzyme and then transfer them to another enzyme where the electrons are released to a substrate in a different reaction? | coenzymes |
| During each energy conversion that happens in a living organism, some of the energy dissipates as _______. | Heat |
| Increasing the temperature of an uncatalyzed reaction _______ the rate of that reaction. | increases |
| A substance that binds to an enzyme in away which results in a decrease of enzymes activity is called a(n)________. | inhibitor |
| Characteristic of enzymes? | They lower the activation energy of a reaction by binding to the substrate |
| What type(s) of reactions occur spontaneously? 1. Reactions with + change in free energy. 2. Reactions with - change in free energy. 3. Exergonic 4. Endergonic | Reactions with - change in free energy and exergonic |
| The ___________ ____________ for an exergonic reaction is lower in the presence of a catalyst for the reaction. | activation energy |
| What are competitive inhibitors? | Bind to the active site of an enzyme and prevent substrates from binding |
| What type of reaction or process releases free energy? | Exergonic |
| What is a noncompetitive inhibitor? | A molecule that binds to an allosteric site and prevents the proper functioning of an enzyme |
| In ___________ _________, usually the end product of a series of reactions affect the first enzyme in the series to shut down the pathway | feedback and inhibition |
| Enzyme-mediated chemical reactions take place when the substrate molecules bind at the _______ _______ of an enzyme. | active site |
| The _______ Law of Thermodynamics concerns transformations of energy, while the _______ Law of Thermodynamics the total amount of energy in the universe. | Second and First |
| What is a substrate? | A reactant molecule that binds to the active site of an enzyme |
| During photosynthesis, small inorganic molecules are converted into organic molecules using energy from? | Sunlight |
| Many __________ are metal ions that participate in the reaction inside the active site | cofactors |
| Heat is a form of kinetic _________ that can flow between two samples of matter if there is a difference in their _________. Since cells are too small to maintain such a different (or gradient) they cannot use heat to do work. | energy and temperature |
| The rate of an exergonic reaction can be increased by lowering the ___________ energy required to destabilized chemical bond in the reactants. | activation |
| The two main steps in the ATP cycle the synthesis of _____ from ADP and P1 and the hydrolysis of ATP to release ______ that drives endergonic reactions. | ATP and energy |
| According to the Second Law of Thermodynamics, _______ increase when energy is transferred from one form to another and some is lost as heat in the process. | Entropy |
| Pepsin is an enzyme found in the stomach that function best at the acidic pH. Why does pepsin not function well at a pH of 7? | Enzymes are sensitive to pH and function best across a narrow range of pH |
| Most endergonic reactions in the cell require ______ energy than is released by the hydrolysis of ATP. | less |
| Energy is usually measured as which of the following? | Heat |
Created by:
458Jenna