Chapter 4

25 July 2022
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question
Fermentation reactions generally occur under conditions of:
answer
low oxygen concentrations
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All alcoholic beverages are produced as the result of:
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cellular respiration by yeast occurring in the absence of oxygen.
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Potential energy is to kinetic energy as ______________ is to _____________.
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water held behind a dam, water power being used to turn electric turbines
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Which of the following energy-generating processes is the only one that occurs in all living organisms?
answer
glycolysis
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In glycolysis, one molecule of glucose containing 6 carbons is converted to two molecules of ________ containing 3 carbons each. This reaction also yields two molecules of _______ and two molecules of _______.
answer
Pyruvate; ATP; NADH
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When fermentation occurs in grapes left on the vine, the final product is the ethanol used to make wine. When fermentation occurs in our muscles, the final product is:
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2 lactic acid molecules.
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The three different known biochemical pathways organisms will use to photosynthesize include which of the following?
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C3, C4, CAM
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The first law of thermodynamics states that energy is constant; it can ____________________, but not _______________.
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be transferred and transformed; created or destroyed
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When ATP is hydrolyzed to ADP, what happens?
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One phosphate is removed.
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How many phosphates do ADP & ATP each have?
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2, 3
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Every time a source of energy is converted from one form to another:
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some of the energy is converted to heat, which is one of the least usable forms of kinetic energy.
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Carbon dioxide enters a plant through which of the following?
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stomata.
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The generation of ATP by the movement of protons down their concentration gradient, occurs in:
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both a) and b) mitochondria and chloroplasts
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Which of the following is NOT a form of kinetic energy?
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a covalent bond linking phosphate molecules
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The word anabolism refers to constructive, build-up, or synthesis reactions while the word catabolism refers to destructive, breakdown, or digestive reactions. What does it mean to say that in a cell, catabolism fuels anabolism?
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Cellular respiration (catabolism) forms the ATP that is used to power anabolic reactions.
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The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. What can you conclude from these graphs?
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The colors of leaves in the fall are a consequence of reduced amounts of chlorophylls a and b in the leaves.
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A molecule of chlorophyll increases in potential energy:
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when one of its electrons is boosted to a higher-energy excited state upon being struck by a photon of light.
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Which by-product of photosynthesis was important in altering the atmosphere of the earth so that aerobic organisms could evolve?
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oxygen
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Chlorophyll a and b are green-colored molecules. What color(s) of light do they reflect?
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only green
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According to the clip, what is the main function of photosynthesis?
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make sugars for food
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Where does the Calvin cycle take place?
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stroma of the chloroplast
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Watch the video clip which shows details of what happens to electrons when sunlight hits the leaf and the chloroplasts in it. Which of the following describes the function of water in this part of photosynthesis
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provides electrons to replace those sent to the electron transport chain
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During fermentation, yeast cells convert pyruvate to ethanol and CO2. Fermentation also occurs in human muscle cells when oxygen is depleted. In the case of muscle cells, what are the byproduct(s) of the fermentation of pyruvate?
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lactic acid
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Oxygen gas produced during photosynthesis originates as:
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oxygen atoms contained in water molecules.
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Although the reactions of the Calvin cycle do not depend directly on light, they do not usually occur at night. Why?
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The Calvin cycle depends on products of the light reactions which cannot occur at night.
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The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. Why are there two graphs shown here?
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The two graphs are each measures of the amounts of pigment, for three different pigments, in spring versus fall.
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Biologically speaking, a pigment:
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is a MOLECULE that absorbs a photon
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Animal fats and plant oils are sometimes used as sources of fuel for automobile engines. How is energy harvested from these molecules?
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They contain long chains of hydrocarbons that, when broken, release the energy stored in the bonds linking the atoms together.
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When a chlorophyll molecule absorbs light, exciting an electron, the chlorophyll molecule:
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gains potential energy.
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Which of the following products of the light reactions of photosynthesis are later employed in the Calvin cycle?
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NADPH and ATP
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When ATP is hydrolyzed to ADP, what happens?
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One phosphate is removed.
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Plants, protists, fungi, and animals are all known to obtain energy through aerobic respiration. Which of the following must be present in all these organisms for this to be true?
answer
mitochondria
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Where does the Krebs (citric acid) cycle occur in eukaryotic cells?
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the mitochondrial matrix
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The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. The graphs indicate that in the fall chlorophyll a and b molecules are broken down and stored in the branches of the plant. As light from the fall sun hits the leaf, what is the result?
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The light reflected from the leaf is orange.
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What is the first step in CAM photosynthesis?
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Plants open their stomata at night to take in carbon dioxide.
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The energy transformation pathways of cellular respiration and photosynthesis are related in which of the following ways?
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b), c), and d) are correct.
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Humphrey Bogart said in Casablanca that some things "don't amount to a hill of beans in this crazy world." But a "hill of beans" does have energetic value, both as food and as a tall hill. In what form(s)is/are the energy in this bean hill?
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Both a) and c) are true.
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A cyclist rides her bike up a very steep hill. Of the following choices, which statement properly describes this example in energetic terms?
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Both a) and d) are correct.
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The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. Which of the following is true about the graph above?
answer
The y-axis indicates how much of the pigment molecule is present in the leaves.
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When fermentation occurs in grapes left on the vine, the final product is the ethanol used to make wine. When fermentation occurs in our muscles, the final product is:
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2 lactic acid molecules.
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Anaerobic mammals:
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do not exist.
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Which of the following statements about the light reactions of photosynthesis are correct?
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Only a) and b) are all correct.
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Which one of the following statements best represents the relationship between respiration and photosynthesis?
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Photosynthesis stores energy in complex organic molecules, while respiration releases it.
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What happens to the pyruvate molecules produced through glycolysis?
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Both answers a) and b) are correct.
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What are the resulting products of the splitting of water in photosynthesis?
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electrons, oxygen, and hydrogen ions
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______________ is a thick fluid inside the chloroplast membrane. Suspended within it are disk-like membranous sacs known as _______________, which are concentrated in stacks called _______________.
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The stroma, thylakoids, grana
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During C4 photosynthesis:
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plants are able to continue producing sugars even when they must close their stomata to reduce water loss during hot days
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How many turns of the Krebs cycle (also called the citric acid cycle) are needed to fully breakdown the energy in one glucose molecule?
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2 turns
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The three steps, in order, of the Calvin Cycle are:
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fixation of CO2, sugar creation, regeneration.
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File this one under "confusing plant terminology." Both a plant's stoma and its stroma are important in photosynthesis. What's the difference between stoma and stroma?
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Stoma is the singular of stomata, the gas exchange pores in the leaf of the plant, while stroma is the fluid that fills the inner space of a chloroplast.
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Why are leaves green?
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Chlorophyll molecules mainly absorb light in the blue-violet and red-orange part of the electromagnetic spectrum. Chlorophyll does not absorb much green light, which is reflected to our eyes.
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Photons excite electrons in chlorophyll. These electrons are then trapped by the primary electron acceptor. How does the photosystem replace the trapped electrons?
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The photosystem replaces its light-excited electrons by extracting electrons from water.
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Which of the following does NOT occur during the Calvin cycle?
answer
release of oxygen
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Photosynthesis is the process by which plants, some bacteria, and some protistans, use the energy from sunlight to produce sugar, which _______________ converts to ATP, the "fuel" used by all living things.
answer
cellular respiration
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Which of the following energy-generating processes is the only one that occurs in all living organisms?
answer
glycolysis
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Plants that carry out the Calvin cycle during the day when the stomata are closed and fix carbon dioxide into organic acids at night when the stomata are open are called:
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green algae.
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During photosynthesis, visible light has enough energy to:
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excite electrons.
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The most abundant protein in the world is the enzyme that initiates the fixation of carbon in the Calvin cycle. This enzyme is called:
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rubisco.
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According to the clip, the light-capturing pigment molecules are called:
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photosystems.
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The carbon dioxide needed for photosynthesis enters the plant through the:
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stomata
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In photosynthesis, both the first and the second photosystems:
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generate energy storage molecules.
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Three different metabolic pathways are responsible for the production of ATP. What are they?
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glycolysis, the reactions on the electron transport chain, and the Krebs (citric acid) cycle
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Which of the following statements about the DIFFERENCES between the chlorophyll a molecule at the center of a photosystem and chlorophyll elsewhere in the photosystem is NOT true?
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Chlorophyll a at the photosystem center has one more electron in its chemical structure than do the chlorophyll molecules elsewhere in the photosystem.
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The first cells evolved in an atmosphere that lacked free _____________. Their metabolism resulted in the accumulation of ________________ in the atmosphere.
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oxygen; carbon dioxide
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ATP is produced in the mitochondria by a series of biochemical reactions. In what order do these reactions occur?
answer
glycolysis; the Krebs (citric acid) cycle; the electron transport chain
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An inherited disease results from abnormal mitochondria passed from mother to child. Using your knowledge of mitochondria's function within human cells, which of the following is the most likely description of the symptoms of this disease?
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extreme muscle weakness
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Chlorophyll b and the carotenoids are important as receptors of light energy because they:
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respond to wavelengths different from the wavelengths that chlorophyll a responds to
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A cyclist rides her bike up a very steep hill. Pick from the following choices the one that properly describes this example in energetic terms.
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Both a) and d) are correct.
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The specialized cells that facilitate gas exchange in plants are known as:
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guard cells
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The electron-transport chains of chloroplasts convey electrons to the ___________-producing photosystem, while at the same time providing energy for the synthesis of _________.
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NADPH; ATP
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A green plant can carry out photosynthesis if given nothing more than:
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water, light, and air.
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What is the source of the electrons that replace those lost by chlorophyll a in the photosystems?
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water
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In plant cells, chloroplasts:
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Both b) and d) are correct.
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Photosystems:
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are arrangements of light-catching pigments within chloroplasts.
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Oxygen gas produced during photosynthesis originates as:
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oxygen atoms contained in water molecules.
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NADH:
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is the reduced form of NAD+.
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The generation of ATP by the movement of protons down their concentration gradient, occurs in:
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both a) and b) mitochondria and chloroplasts
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Plants that carry out the Calvin cycle during the day when the stomata are closed and fix carbon dioxide into organic acids at night when the stomata are open are called
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CAM plants.
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The light reactions of photosynthesis supply the Calvin cycle with:
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ATP and NADPH & H+
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The actual production of sugars during photosynthesis takes place:
answer
within the stroma, outside of the thylakoid, but still inside the chloroplast
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Each ATP molecule is composed of three separate subunits. Which of the following is NOT a proper description of one of these subunits?
answer
three carbon-nitrogen rings
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During photosynthesis, which of the following is the most important molecule in the conversion of light energy from the sun into chemical energy?
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`chlorophyll
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A molecule of glucose sugar is used by the cells of your body to make about 34-36 ATP. This means that:
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glucose carries at least 30-40 times the energy of an ATP molecule.
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In cellular respiration:
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a), b), and c) are correct.
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Aerobic bacteria:
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lack mitochondria.
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In your body, when energy is released from the breakdown of a molecule such as glucose:
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some of it may be harnessed by building the unstable high-energy bonds that attach phosphate groups to ATP.
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Which of the following is NOT a product of photosynthesis?
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carbon dioxide
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Within the study of thermodynamics, a closed system is defined as system in which energy does not come in and energy does go out. Which of the following is considered a closed system?
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the universe
question
Light has both the properties of a wave and of a particle. Why is this dual model of light necessary for understanding photosynthesis?
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The wavelength of the light determines whether the chlorophyll molecule will absorb it, while the particles, photons, are responsible for exciting the electrons in the chlorophyll molecule.
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If photosynthesis produces cellular energy (ATP) from sunlight, why do plant cells also need to perform cellular respiration, a process that produces ATP from sugar?
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Plant cells cannot make cellular energy at night; therefore photosynthesis actually stores ATP energy as sugar, which can be then converted back to ATP at night by cellular respiration.
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Cellular respiration is an efficient process that captures around 35% of the energy in glucose. From one molecule of glucose, it yields:
answer
approximately 36 ATP.
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What accepts the electrons from NADH during fermentation so that it may be recycled into the empty electron carrier, NAD+
answer
pyruvate
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The conversion of radiant energy to chemical energy occurs in photosynthesis and many other common phenomena, such as brewing tea, fading of dyes in the sun, and photography. In what way is photosynthesis different from these other processes?
answer
Photosynthesis fixes light energy in the form of high potential chemical energy in compounds that do not break down spontaneously and that can be stored until required later for the carrying out of life processes.
question
The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. What do the colors represent in these graphs?
answer
The color of light reflected by each pigment.
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The phosphate groups in ATP:
answer
release energy when separated from the rest of the molecule.
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Where does the Calvin cycle take place?
answer
stroma of the chloroplast
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The generation of ATP by the movement of protons down their concentration gradient, occurs in:
answer
both a) and b) mitochondria and chloroplasts
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A student builds a model of an ATP molecule out of some scraps she finds at home. She uses a block of wood for the bulk of the molecule which she labels ADP. She attaches the block to a spring and then compresses the spring between the block and a smaller round paper weight. What does the coiled spring represent in an actual molecule of ATP?
answer
the covalent bond between the last phosphate and the middle phosphate
question
A pigment that absorbs all wavelengths of visible light appears:
answer
black.
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In photosynthesis, both the first and the second photosystems:
answer
generate energy storage molecules.
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During photosynthesis, which step is most responsible for a plant's acquisition of new organic material:
answer
the plucking of carbon molecules from the air and fixing of them to organic molecules within the chlorplast
question
You eat a chocolate bar to get you through a late-night studying session. Quickly your body begins to break down the macromolecules in the candy and utilize the sugars, lipids and protein to make ATP. Which of the following is NOT a step in the process of breaking down the candy bar's macromolecules?
answer
All of the above steps are part of the break down of the candy bar's macromolecules.
question
To synthesize 1 glucose molecule, the Calvin cycle uses _______ molecules of CO2, _______ molecules of ATP, and ________ molecules of NADPH.
answer
6, 18, 12
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Phosphorus is an important nutrient for plants and animals because it is a component of:
answer
DNA, RNA, and ATP.
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Why must plants get water in order for photosynthesis to occur?
answer
replace electrons sent to the electron transport chain
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Where are the molecules of the mitochondrial electron transport chain located?
answer
within in the inner membrane
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The electrons at the very end of both photosystems are eventually picked up by an electron carrier to become:
answer
NADPH.
question
When a photon strikes a molecule, the photon may
answer
a) and c) are correct
question
Which of the following is NOT one of the major molecular changes that occurs in glycolysis?
answer
Two molecules of pyruvate are converted into two molecules of Acetyl-CoA.
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The original source of electrons in the photosystems is:
answer
H2O.
question
When amino acids are used in cellular respiration to make ATP, what part must be removed that often ends up in the urine?
answer
amino
question
In harvesting the chemical energy of the molecules in food:
answer
organisms can use sugars lipids and proteins
question
With regards to special mechanisms of photosynthesis in hot or dry climates, ________ photosynthesis separates carbon dioxide capture and the Calvin cycle physically while _________ photosynthesis separates carbon dioxide capture and the Calvin Cycle in time.
answer
C4, CAM
question
Which of the following metabolic processes results in the production of ATP in the absence of oxygen?
answer
glycolysis
question
During electron transport in photosynthesis, the inner compartment of the thylakoid membrane becomes:
answer
more acidic than the stroma.
question
A green automobile hood exposed to sunlight will produce far more heat than a green leaf exposed to the same amount of sunlight. Why is this?
answer
The automobile hood has no mechanism for capturing the energy of its excited electrons, so it releases that energy as heat as the electrons fall back to their ground state; a leaf contains primary electron receptors, which will capture the energy and put it to use in making ATP and NADPH.
question
How many rotations of the Calvin cycle are required for the production of one glucose molecule?
answer
6
question
In photosynthesis, gaseous molecular oxygen (O2) is released. This comes from a compound that goes into photosynthesis. Which compound is it?
answer
water (H2O)
question
A green plant can carry out photosynthesis if given nothing more than:
answer
water, light, and air.
question
The actual production of sugars during photosynthesis takes place:
answer
within the stroma, outside of the thylakoid, but still inside the chloroplast.
question
Which of the following processes does NOT take place in the cytosol in eukaryotic cells?
answer
conversion of pyruvate into acetyl CoA
question
Which of the following is NOT one of the major molecular changes that occurs in glycolysis?
answer
Two molecules of pyruvate are converted into two molecules of Acetyl-CoA.
question
Where does the new mass of a plant come from as it grows?
answer
capture of carbon dioxide
question
Which of the following is the LEAST likely effect of a drug that binds to (and inactivates) oxaloacetate?
answer
It would prevent the cleavage of glucose into pyruvate.
question
Which of the following sequences accurately represents the flow of electrons during photosynthesis?
answer
H2O ā†’ NADPH ā†’ Calvin cycle
question
Which of the following does NOT occur during the Calvin cycle?
answer
generation of oxygen
question
If a thylakoid were punctured so that its interior was no longer separated from the stroma, which of the following processes would be most directly affected?
answer
the synthesis of ATP
question
Energized electrons from the water-splitting photosystem pass down an electron-transport chain to the ___________-producing photosystem.
answer
NADPH
question
The Calvin Cycle produces G3P, with the formula C3H7O6P. This is combined inside the chloroplast to make the six-carbon glucose sugar, C6H12O6. How many turns of the Calvin Cycle would be required to build and produce a completed glucose molecule?
answer
6
question
When ATP is hydrolyzed to ADP, what happens?
answer
One phosphate is removed.
question
When a muscle cell metabolizes glucose in the complete absence of molecular oxygen, all of the following substances are produced EXCEPT:
answer
Acetyl-CoA.
question
C4 plants have better water conservation abilities than do many other plants (especially C3). This is because:
answer
C4 plants open their stomata at night.
question
Which of the following would be a typical product of the dark reactions of photosynthesis?
answer
3-phosphoglycerate acid (3-PGA)
question
Which of the following is NOT a form of kinetic energy?
answer
a covalent bond linking phosphate molecules
question
Theodor Engelmann broadcast light that had been passed through a prism onto a mat of algae. This exposed different parts of the algae to different wavelengths of light. When he added aerobic bacteria to the system, he noted that the largest groups of bacteria aggregated in the areas of the algae illuminated by the blue and red light. What did Engelmann discover from this experiment?
answer
Bacteria aggregated in the area in which the most oxygen was being released.
question
The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. What is the independent variable presented in these graphs?
answer
Time at which the amount of pigment in the leaves was measured.
question
The original source of electrons in the photosystems is:
answer
H2O.
question
In photosynthesis, as electrons pass from carrier to carrier in redox reactions, hydrogen ions removed from ___________ are deposited in ______________.
answer
the stroma; the thylakoid space
question
The first cells evolved in an atmosphere that lacked free _____________. Their metabolism resulted in the accumulation of ________________ in the atmosphere.
answer
oxygen; carbon dioxide
question
Different steps in cellular respiration occur in different locations in the mitochondria. Which of the following does not properly match a step of respiration to its proper location?
answer
molecule of CO2 released: inner mitochondrial membrane
question
When amino acids are used in cellular respiration to make ATP, what part must be removed that often ends up in the urine?
answer
the amino group
question
What accepts the electrons from NADH during fermentation so that it may be recycled into the empty electron carrier, NAD+
answer
pyruvate
question
During photosynthesis, visible light has enough energy to:
answer
excite electrons.
question
In chloroplasts, the process that occurs at the electron transport chain leads to:
answer
the establishment of a proton gradient.
question
Which of the following statements about the DIFFERENCES between the chlorophyll a molecule at the center of a photosystem and chlorophyll elsewhere in the photosystem is NOT true?
answer
Chlorophyll a at the photosystem center has one more electron in its chemical structure than do the chlorophyll molecules elsewhere in the photosystem.
question
A pigment that absorbs all wavelengths of visible light appears:
answer
black.
question
The water released during cellular respiration is called:
answer
metabolic water.
question
All of the following statements regarding C4 plants are correct EXCEPT:
answer
Rubisco is no longer necessary to make glucose.
question
Which of the following does NOT occur as a direct result of a photon hitting a chlorophyll molecule?
answer
production of NADPH and H+
question
The most effective portion(s) of the visible spectrum in driving photosynthesis is (are):
answer
the violet-blue portion.
question
Which of the following statements is most correct concerning the movement of materials through the stomata?
answer
Water and O2 move out; CO2 moves in.
question
Which of the following statements most accurately depicts the relationship between the light reactions and the Calvin cycle in photosynthesis?
answer
The Calvin cycle supplies ADP, NADP+, and a phosphate group to the light reactions, and the light reactions return ATP and NADPH to the Calvin cycle.
question
When both light and temperature are increased, the rate of photosynthesis will:
answer
increase because the activity of the photosystems will increase because of the increase in light and the activity of the Calvin cycle will increase because of the increase in temperature.
question
What happens to electrons as they are passed down the photosynthetic electron transport chain from the primary electron acceptor?
answer
they fall to a lower energy state and some energy is released
question
A plant whose leaves are reddish yellow is NOT absorbing light from which wavelengths of the visible light spectrum?
answer
red and yellow Both b) and c) are correct.
question
Which wavelengths are absorbed by chloroplasts during photosynthesis?
answer
Both b) and c) are correct.
question
Carotenoids:
answer
are accessory pigments in chloroplasts that protect the chlorophyll by absorbing excessive light energy.
question
The specialized cells that facilitate gas exchange in plants are known as:
answer
stomata.
question
Which of the following processes does NOT take place in the cytosol in eukaryotic cells?
answer
conversion of pyruvate into acetyl CoA
question
Most plant leaves contain yellow and orange carotenoids as well as green chlorophylls. Why then are most leaves greenish?
answer
There is a much greater concentration of chlorophylls than carotenoids in plant leaves.
question
Energy used in cellular respiration can originate from:
answer
carbohydrates, proteins, and fats.
question
When a muscle cell metabolizes glucose in the complete absence of molecular oxygen, all of the following substances are produced EXCEPT:
answer
Acetyl-CoA.
question
Which of the following statements most accurately depicts the relationship between the light reactions and the Calvin cycle in photosynthesis?
answer
The light reactions provide ATP and NADPH to the Calvin cycle and the Calvin cycle returns ADP, NADP+, and a phosphate group to the light reactions.
question
During cellular respiration, most of the energy contained within the bonds of food molecules is captured in:
answer
the krebs cycle and electron transport chain
question
The original source of electrons in the photosystems is:
answer
H2O.
question
Which of the following is NOT one of the major molecular changes that occurs in glycolysis?
answer
Two molecules of pyruvate are converted into two molecules of Acetyl-CoA.