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Q:
Which of the following describes a transition state molecule?
A) the distorted shape the product takes while being released from the enzyme
B) the distorted shape the substrate takes when being converted by an enzyme into product
C) the distorted shape the enzyme takes when converting substrate into product
D) the distorted shape a coenzyme takes while it is bound to an enzyme
Q:
The function of chymotrypsin is to:
A) break down proteins into amino acids.
B) synthesize glycogen.
C) synthesize proteins.
D) break down glycogen into glucose.
Q:
Which of the following is true of vitamins?
A) They serve as a major energy source for cells.
B) They are the main component of enzymes.
C) They can serve as enzymes.
D) They can serve as coenzymes.
Q:
Where do substrates bind to enzymes?
A) in the active site
B) anywhere
C) in the substrate groove
D) in the effector site
Q:
Which of the following statements concerning enzymes is false?
A) They accelerate the rate of chemical reactions.
B) Many activities in living organisms require multiple enzymes.
C) One enzyme will work on many different substrate molecules to produce many different products.
D) They can carry out hundreds of chemical transformations per second.
Q:
Coenzymes:
A) serve as catalysts.
B) make proteins.
C) help enzymes to function.
D) break down sugars.
Q:
Which would be an example of a catalyst in action?
A) a glycoprotein binding to a cell
B) a protein converting glucose and fructose into sucrose without being changed itself
C) glucose and galactose binding to form lactose
D) a phosphate group attached to a protein changing its shape
Q:
Which of the following statements concerning enzymes is false?
A) They function as catalysts.
B) The active site of an enzyme has a shape that is specific for its given substrate.
C) They increase the activation energy required for chemical reactions to proceed.
D) Many enzymes utilize coenzymes, such as vitamins.
Q:
Most enzymes are:
A) proteins.
B) nucleic acids.
C) lipids.
D) vitamins.
E) carbohydrates.
Q:
What makes an enzyme a catalyst?
A) its ability to change shape to fit the substrate
B) it speeds up a chemical reaction but can only be used once
C) it speeds up a chemical reaction but becomes changed by the reaction
D) it speeds up a chemical reaction but is not changed by the reaction
E) its amino acids
Q:
Gasoline will not burn in your car's engine unless it is ignited with a spark from a sparkplug. In this situation, the spark is providing:
A) activation energy.
B) hydrolytic energy.
C) coenzyme energy.
D) enzymatic energy.
E) entropy.
Q:
Some enzymes contain molecules in the active site that help facilitate chemical transformations. These molecules are called:
A) coenzymes.
B) products.
C) substrates.
D) co-substrates.
Q:
Enzymes work to speed up a chemical reaction by:
A) supplying the energy needed for the reaction.
B) increasing the activation energy of the reaction.
C) lowering the activation energy of the reaction.
D) attaching coenzymes to the substrate.
E) heating up the substrate.
Q:
Metabolism is the sum of all the:
A) ATP a cell contains.
B) energy a cell uses.
C) chemical reactions that a cell carries out.
D) vitamins a cell contains.
E) enzymes a cell contains.
Q:
In a ________, multiple enzymes are working together in a multistep process.
A) feedback loop
B) coupled reaction
C) allosteric pathway
D) metabolic pathway
Q:
The diversity of chemical reactions occurring in a cell depends mostly on certain molecules present in the cells, which are called:
A) enzymes.
B) proteins.
C) cofactors.
D) coenzymes.
E) ribozymes.
Q:
You have a friend who tells you she is lactose intolerant. She asks you to explain what this means. You say to her:
A) "You cannot digest milk because you cannot absorb it in your intestines."
B) "You are allergic to milk."
C) "You cannot digest milk because you do not have the enzyme to break down the sugar in the milk."
D) "You cannot digest the milk because you do not have the enzyme to break down the protein in the milk."
E) "You cannot digest the milk because you do not have the enzyme to break down the lipid in the milk."
Q:
The substance that is worked on by an enzyme is called:
A) product.
B) coenzyme.
C) inhibitor.
D) substrate.
Q:
In the following reaction, which of the following is an example of a substrate?
Lactase
Lactose → Glucose + Galactose
A) galactose
B) glucose
C) lactose
D) lactase
Q:
The structure of ATP includes each of the following except:
A) the nitrogenous base adenosine.
B) the sugar ribose.
C) the nitrogenous base adenine.
D) phosphate groups.
Q:
In the ATP/ADP cycle:
A) food provides the energy needed to link phosphate to ADP to make ATP.
B) food provides the energy needed to break down ATP into ADP.
C) converting ADP into ATP is an energy-yielding reaction, whereas converting ATP into ADP is an energy-requiring reaction.
D) after powering a reaction, ADP becomes ATP.
Q:
What is the energy currency of cells?
A) ATP
B) glucose
C) enzymes
D) ADP
E) vitamins
Q:
The energy released during ________ reactions can be used to drive ________ reactions, and this is called ________ reactions.
A) endergonic; exergonic; coupled
B) exergonic; endergonic; coupled
C) endergonic; exergonic; mutually dependent
D) exergonic; endergonic; mutually dependent
Q:
Coupled reactions are:
A) reactions in which endergonic reactions obtain the energy to go forward from exergonic reactions.
B) reactions in which exergonic reactions obtain the energy to go forward from endergonic reactions.
C) any reactions that are accelerated by an enzyme.
D) reactions that lower the activation energy of another reaction.
Q:
In the reaction glucose + oxygen → carbon dioxide + heat, the:
A) products have more potential energy than the reactants.
B) products have less potential energy than the reactants.
C) products have the same amount of potential energy as the reactants.
D) entropy has decreased.
Q:
Which of the following is exergonic?
A) bringing glucose molecules together to form glycogen
B) plants producing glucose from CO2
C) bringing amino acids together to form proteins
D) cells breaking down glucose into CO2
Q:
Which of the following is endergonic?
A) cells breaking down glucose into CO2
B) the burning of wood
C) the digestion of proteins in the stomach
D) breaking bonds in starch to produce glucose
E) the synthesis of glucose from carbon dioxide and water
Q:
Which of the following is true of energy?
A) It can be stored in chemical bonds.
B) It can be released by forming chemical bonds.
C) It can be transferred from one form to another with 100 percent efficiency.
D) It can be created from nothing.
Q:
Energy present in a system that is not usable to do work relates to the system's:
A) thermodynamics.
B) equilibrium.
C) work.
D) entropy.
E) temperature.
Q:
During photosynthesis, plants use light energy to synthesize glucose from carbon dioxide. However, plants do not use up energy during photosynthesis; they merely convert it from light energy to chemical energy. This is an illustration of:
A) spontaneous reaction.
B) chemical equilibrium.
C) the second law of thermodynamics.
D) the first law of thermodynamics.
E) increasing entropy.
Q:
What percentage of the energy stored in glucose do humans recover by cellular respiration?
A) 100 percent
B) 48 percent
C) 52 percent
D) 37 percent
E) 15 percent
Q:
The second law of thermodynamics states that:
A) energy is required to bring molecules into a cell against a concentration gradient.
B) energy can be neither created nor destroyed.
C) all living organisms must eat to derive energy.
D) in energy-yielding reactions, matter goes from a more-ordered to a less-ordered state.
Q:
The first law of thermodynamics states that:
A) energy is required to bring molecules into a cell against a concentration gradient.
B) in energy-yielding reactions, matter goes from a more-ordered to a less-ordered state.
C) energy can be neither created nor destroyed.
D) all living organisms must eat to derive energy.
Q:
Which of the following accurately describes energy?
A) something that can cause movement
B) something that produces heat
C) something that has the capacity to do work
D) something that must be eaten
E) something that provides sunlight
Q:
You work hard to pedal your bicycle up a steep hill. You rest when you get to the top, then you let your bicycle roll quickly down the other side of the hill. You converted ________ energy into ________ energy, then you converted it back into ________ energy.
A) potential; kinetic; potential
B) kinetic; potential; kinetic
C) heat; kinetic; heat
D) heat; potential; heat
Q:
Kinetic energy is ________ and potential energy is ________.
A) stored energy; energy that is being used
B) stored energy; energy that can't be used
C) energy that can't be used; stored energy
D) energy that is being used; stored energy
Q:
Glucose can be broken down to provide energy for the beating of cilia. Therefore, the glucose must contain:
A) potential energy.
B) kinetic energy.
C) heat energy.
D) entropy.
Q:
When you digest the starch in plants into glucose, some energy is lost as heat. This increases the ________ of the universe.
A) energy
B) order
C) entropy
D) potential
E) equilibrium
Q:
Entropy is the measure of ________ in a system.
A) energy
B) disorder
C) work
D) order
E) heat
Q:
When we metabolize our food, we produce heat that helps to keep us warm. Which of the following best describes why?
A) Chewing is exothermic; therefore, energy is released in the form of heat when we eat food.
B) When we break down food, all energy in the food is directly released in the form of heat.
C) Producing ATP from ADP is exothermic; therefore, energy is released in the form of heat.
D) When we break down our food, the reactions are not 100 percent efficient; therefore, energy is lost as heat.
Q:
Which of the following has the most entropy?
A) steam
B) snow
C) an ice cube
D) hot water
E) liquid water
Q:
Living things are highly ordered. So why does life not violate the second law of thermodynamics?
A) Life can only violate the first law of thermodynamics.
B) Life only needs to follow the first law of thermodynamics.
C) Life takes in energy to maintain order and, in doing so, decreases order elsewhere.
D) Life gives off energy to maintain order and, in doing so, decreases order elsewhere.
Q:
Which law of thermodynamics explains the fact that we must eat to gain the energy to perform the functions of life, such as breathing?
A) second law
B) fourth law
C) fifth law
D) first law
E) third law
Q:
Plants provide animals with which of the following?
A) food
B) oxygen
C) carbon dioxide
D) food and oxygen
E) food and carbon dioxide
Q:
Refer to the figure below, and then answer the question that follows.The type of transport shown is an example of:A) simple diffusion.B) active transport.C) endocytosis.D) exocytosis.E) facilitated diffusion.
Q:
Refer to the figure below, and then answer the question that follows. For this type of transport to take place, which of the following must be true about the interior and exterior environments?A) The amount of glucose outside the cell must be less than the interior concentration.B) The glucose concentration must be higher outside the cell than inside the cell.C) The glucose concentrations on both sides of the cell must be the same.D) A transport protein is involved, so it doesn't matter what the concentrations of glucose are on either side of the membrane.
Q:
What are two major differences between active transport and passive transport? Please give a specific example of each that occurs within a eukaryotic cell.
Q:
An accident victim lost a lot of blood and was rushed to the emergency room. In the emergency room, the first thing the doctors did was replace lost fluids by giving an IV of pure water. But this caused the patient to die. Propose a reason why the patient died.
Q:
A woman suffering from severe dehydration goes into the hospital. The doctor tells the woman that her blood has far too much solute in it and not enough water. Explain how this condition could affect the cells of her body and why.
Q:
The plasma membrane proteins of a cell can be linked to colored marker molecules. In an experiment, you labeled the membrane proteins of one cell with a red marker and the membrane proteins of a second cell with a blue marker. Using your understanding of the fluid-mosaic model, what might you see happen if you connected the plasma membranes of the two cells so that they form one continuous membrane?
Q:
________ is the process that a cell can use to bring very large molecules into the cell.
Q:
A ________ plasma membrane allows water but not solutes to pass through it.
Q:
Osmosis refers to the diffusion of ________ across a membrane.
Q:
The ________ functions in cell lubrication, adhesion, and signaling.
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisUses a transport vesicle to release materials to the exterior of a cell
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisUses a transport vesicle to bring large materials into the cell
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisRequires the expenditure of energy to move molecules or ions across a cell membrane
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisMovement of materials across a cell membrane that does not require energy
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisUses transport proteins to assist the movement of materials down a concentration gradient
Q:
Match the following.A) passive transportB) facilitated diffusionC) simple diffusionD) exocytosisE) active transportF) endocytosisThe movement of molecules down their concentration gradient without the use of a transport protein
Q:
Phagocytosis is an example of passive transport.
Q:
Exocytosis is an example of active transport of a substance into the cell.
Q:
To move a molecule into a cell against the concentration gradient requires energy.
Q:
Active transport moves a substance against the concentration gradient.
Q:
Facilitated diffusion occurs down a concentration gradient.
Q:
Facilitated diffusion occurs through membrane-bound transport proteins.
Q:
A substance moving down the concentration gradient is an example of active transport.
Q:
A cell wall stops a plant cell from taking in so much water that it will burst.
Q:
Diffusion occurs because of random molecular movement.
Q:
Osmosis is an example of passive transport.
Q:
Water moves freely through a semipermeable membrane.
Q:
The most up-to-date explanation of the structure of the plasma membrane is called the fluid-mosaic model.
Q:
The functioning of the immune system depends on recognition proteins.
Q:
Some integral proteins can span the entire phospholipid bilayer.
Q:
Transport proteins are integral plasma membrane proteins.
Q:
The phospholipid bilayer forms because fatty-acid tails do not dissolve in water.
Q:
The phospholipid bilayer forms spontaneously in water.
Q:
Cholesterol helps to maintain the correct fluidity of the plasma membrane.
Q:
Signals sent between cells reach a cell at receptor proteins.
Q:
Hydrophobic molecules easily pass through the fatty-acid region of the plasma membrane.