Bio chapter 5
Most enzymes are _____. carbohydrates proteins lipids nucleic acids minerals
Proteins
Which choice describes a laboratory technique that scientists might use to mimic a natural genetic process of cells? phosphate transfer nanotechnology catalysis directed evolution
directed evolution
The reaction ADP + P --> ATP is a(n) _____ reaction. chemical spontaneous hydrolysis exergonic endergonic
endergonic
Which of these reactions requires a net input of energy from its surroundings? hydrolysis ATP --> ADP + P exergonic catabolic endergonic
endergonic
Calories are units of __________. food mass energy ATP entropy
energy
Which is a true statement about the ATP cycle? About 100 ATP molecules are regenerated per second per cell. The ATP cycle does not involve ADP. A single muscle cell needs only about one minute to recycle all of its ATP. The ATP cycle can operate independently of enzyme help.
A single muscle cell needs only about one minute to recycle all of its ATP.
Cells use this molecule to store the chemical energy released by the breakdown of food molecules during cellular respiration. CO2 ATP O2 glucose
ATP
The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium? active transport diffusion passive transport osmosis
active transport
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? redox anabolism potentiation digestion cellular respiration
cellular respiration
Which term is used to describe an animal's ability to survive if the cells are exposed to a hypotonic or hypertonic environment? feedback regulation osmoregulation facilitated diffusion osmosis
osmoregulation
ATP drives work in cells by __________. generating heat diffusing from areas of high concentration to low concentration transferring adenosine to other cell molecules transferring its phosphate group to other cell molecules
transferring its phosphate group to other cell molecules
Which one of the following statements about energy is correct? We convert about 99% of our food energy to useful work. Energy cannot be created or destroyed. Chemical energy is a form of kinetic energy. A leaf falling from a tree represents potential energy.
Energy cannot be created or destroyed.
Chemical energy is a form of _____ energy. motion potential kinetic heat entropic
potential
In cells, what is usually the immediate source of energy for an endergonic reaction? ATP as spontaneous reactions, endergonic reactions do not need an addition of energy ADP glucose sugar
ATP
When cells are placed in hypotonic solutions, both animal and plant cells accumulate water as a result of osmosis. This causes the cells to swell. Why can plant cells better tolerate hypotonic solutions? Plants have contractile vacuoles that continually bail out excess water that enters plant cells. Sunlight causes plant cells to lose water through transpiration. Stomata in plant cell leaves quickly drain excess water from the cells. Animal cells can burst in such situations. In plants, however, rigid cell walls limit how far cells can expand and exert a back pressure to limit further water uptake.
Animal cells can burst in such situations. In plants, however, rigid cell walls limit how far cells can expand and exert a back pressure to limit further water uptake.
The energy for an endergonic reaction comes from a(n) _____ reaction. exergonic anabolic ADP + P --> ATP synthesis glucose + glucose --> maltose
Exergonic
What is the fate of the phosphate group that is removed when ATP is converted to ADP? It is used to convert an ATP into an AQP. It is broken down into one phosphorus and four oxygen atoms. It is acquired by a reactant in an exergonic reaction. It is acquired by a reactant in an endergonic reaction. It is acquired by a reactant in a spontaneous reaction.
It is acquired by a reactant in an endergonic reaction
What name is given to the process by which water crosses a selectively permeable membrane? diffusion pinocytosis passive transport phagocytosis osmosis
Osmosis
Which of these statements is TRUE with regard to this animation? Sodium ions are transported down their concentration gradient. The cell is not expending energy. Sodium and potassium ions are transported against their concentration gradients. Potassium ions are transported down their concentration gradient. The cell does not expend ATP.
Sodium and potassium ions are transported against their concentration gradients.
What best explains the observation that enzymes are selective in the reactions they catalyze? There is a precise compatibility between an enzyme's active site and the substrate molecule. Molecules and active sites vary in size; only properly sized molecules can fit. Active sites carry slight negative charges, and substrates tend to carry slight positive charges. The same enzyme can generally bind to many different types of substrate molecules.
There is a precise compatibility between an enzyme's active site and the substrate molecule.
Which one of the following is an example of osmosis? The smell of freshly baked pie spreads throughout a house. Food in the refrigerator starts to taste like onions because the onions in the vegetable bin have been stored unwrapped. Potassium ions enter a red blood cell through the action of a specific ion transport protein. Water enters a plant by passing through the root cell membranes.
Water enters a plant by passing through the root cell membranes.
Which of the following is an example of potential energy? the mercury rising within a thermometer a hot cup of coffee a bowling ball placed on the top shelf of a closet waves crashing against the shorelin
a bowling ball placed on the top shelf of a closet
Which of these is exhibiting kinetic energy? the high-energy phosphate bonds of a molecule of ATP a space station orbiting Earth a rock on a mountain ledge a person sitting on a couch while watching TV an archer with a flexed bow
a space station orbiting Earth
The use of energy to move molecules across a membrane defines __________. passive transport pinocytosis active transport phagocytosis
active transport
Which are materials found in a molecule of ATP? an organic molecule called cytosine plus three phosphate groups an organic molecule called adenosine plus two phosphate groups amino acids in a precise sequence an organic molecule called adenosine plus three phosphate groups
an organic molecule called adenosine plus three phosphate groups
An enzyme is a protein that __________. provides activation energy for the reactions it facilitates can catalyze many different reactions changes the rate of a metabolic reaction without being consumed by the reaction has only primary structure
changes the rate of a metabolic reaction without being consumed by the reaction
Molecules of food have a form of potential energy called __________. ATP entropy chemical energy kinetic energy
chemical energy
The passive movement of molecules from an area of higher concentration to an area of lower concentration is called __________. endocytosis active transport diffusion phagocytosis
diffusion
"Conservation of energy" refers to the fact that _____. if you conserve energy you will not be as tired the entropy of the universe is always increasing no chemical reaction is 100 percent efficient the net amount of disorder is always increasing energy cannot be created or destroyed but can be converted from one form to another
energy cannot be created or destroyed but can be converted from one form to another
Activation energy can be described as __________. energy needed to activate an enzyme energy needed to activate the reactants and trigger a chemical reaction metabolism energy released by a chemical reaction
energy needed to activate the reactants and trigger a chemical reaction
Every time energy is converted from one form to another, __________. the amount of energy in the universe decreases the amount of energy in the universe increases entropy decreases entropy increases
entropy increases
A(n) _____ reaction occurs spontaneously. exergonic chemical kinetic endergonic anabolic
exergonic
The reaction A --> B + C + heat is released in a(n) _____ reaction. endergonic exchange dehydration synthesis anabolic exergonic
exergonic
How do some inhibitors slow down metabolic pathways when the products of the pathways are not needed but still allow a pathway to proceed when the products are needed? feedback regulation enzyme activation promoting an induced fit between a substrate and an enzyme's active site degrading enzyme molecules
feedback regulation
Which of these are by-products of cellular respiration? ATP and water heat and water glucose and water water ATP
heat and water
In this reaction _____. The figure shows a bar chart of a potential energy of molecules for reactants and products. The reactants are AB and CD, and the products are AC and BD. The potential energy of reactants is much higher than that of products. the chemical energy of the products is greater than that of the reactants the kinetic energy of the reactants is less than that of the products disorder has decreased entropy has decreased heat has been released to the environment
heat has been released to the environment
In cellular respiration, most energy is released and transferred to ATP when _____. low-energy electrons are "raised" to higher energy levels high-energy C-C and C-H bonds in glucose are broken low-energy C-H bonds in glucose are broken high-energy electrons "fall" to lower energy levels
high-energy electrons "fall" to lower energy levels
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule? entropic dehydration synthesis dehydration decomposition anabolism hydrolysis
hydrolysis
In osmosis, water always moves toward the __________ solution, that is, toward the solution with the __________ solute concentration. hypertonic ... greater hypertonic ... lesser isotonic ... greater hypotonic ... greater
hypertonic ... greater
Endocytosis moves materials _____ a cell via _____. out of ... membranous vesicles into ... a transport protein into ... facilitated diffusion into ... membranous vesicles out of ... diffusion
into ... membranous vesicles
An enzyme _____. increases the the activation energy of a reaction is a inorganic catalyst is a source of energy for endergonic reactions can bind to nearly any moleculeis is an organic catalyst
is an organic catalyst
As a result of its involvement in a reaction, an enzyme _____. is used up loses a phosphate group loses energy is unchanged permanently alters its shape.
is unchanged
An animal cell placed in a hypertonic solution will __________. gain water by osmosis and lyse lose water by osmosis and shrivel lose water by active transport and shrivel gain water by pinocytosis and lyse
lose water by osmosis and shrivel
Scientists are exploring an area of modern science called nanotechnology that involves __________. study of energy-deriving metabolic pathways understanding of movement of materials across a membrane manipulation of materials at the molecular level measurement of ATP activity in a test tube
manipulation of materials at the molecular level
Which of the following is highest in chemical energy? one molecule of ATP one molecule of H2 one molecule of glucose one molecule of CO2
one molecule of glucose
A white blood cell engulfing a bacterium is an example of _____. phagocytosis receptor-mediated endocytosis exocytosis facilitated diffusion pinocytosis
phagocytosis
Which one of the following terms is sometimes called "cell eating"? plasmolysis pinocytosis phagocytosis exocytosis
phagocytosis
Enzymes work by _____. adding a phosphate group to a reactant decreasing the potential energy difference between reactant and product increasing the potential energy difference between reactant and product adding energy to a reaction reducing activation energy
reducing activation energy
A characteristic of phospholipids that makes them a candidate for the first organic compounds on Earth to be related to life is their ability to __________. transduce signals form liposomes self-assemble into simple membranes mix freely with water
self-assemble into simple membranes
What name is given to the reactants in an enzymatically catalyzed reaction? reactors active sites substrate products
substrate
Which is the best definition of energy? the conversion of one form of chemical energy to another form of chemical energy the capacity to cause change the conversion of light energy to chemical energy ATP
the capacity to cause change
In this reaction _____. The figure shows a bar chart of a potential energy of molecules for reactants and products. The reactants are AB and CD, and the products are AC and BD. The potential energy of reactants is much higher than that of products. AC is a reactant CD is a product the products have less potential energy than the reactants entropy has decreased the products have been rearranged to form reactants
the products have less potential energy than the reactants
Entropy means that __________. it is not possible to observe an increase in molecular organization life should be impossible energy can be neither created nor destroyed the quantity of usable energy declines with each energy transformation
the quantity of usable energy declines with each energy transformation
What is energy coupling? a barrier to the initiation of a reaction the hydrolysis of ATP to ADP + P a description of the energetic relationship between the reactants and products in an exergonic reaction the use of energy released from an exergonic reaction to drive an endergonic reaction the use of an enzyme to reduce EA
the use of energy released from an exergonic reaction to drive an endergonic reaction