exam 2 study guide

Osmosis

- Focuses on solvent (water) movement rather than solute - Diffusion of water across a differently (selectively) permeable membrane - solute concentration on one side high, but water concentration low - solute concentration on other side low, but water concentration high - Aquaporins - used to maintain water balance in living cells - specific water channels - Osmotic pressure - measuring the flow of water into or out of cell based upon the solutes

Osmosis

- Isotonic Solution - solute and water concentrations equal on both sides of membrane - Hypotonic Solution - Concentration of solute Lower than on other side - Cells placed in a hypotonic solution will swell - May cause cells to break - Lysis - Hypertonic Solution - Concentration of solute Higher than on other side - Cells placed in a hypertonic solution will shrink- Plasmolysis

Membrane Structure and Function

- Passive Transport - Solutions: solute, solvent

Endocytosis

- Phagocytosis: Large, solid material into vesicle - Pinocytosis: Liquid or small, solid particles go into vesicle - Receptor-Mediated: Specific form of pinocytosis using a coated pit

Semipermeable Membrane

- Size - Charge: water is special - Concentration Gradient

Concentration Gradient

- difference between the interior and exterior concentrations - passive transport molecules move with the concentration gradient

Diffusion

- simple - travel across the membrane - Passive transport - small particles - Facilitated - travel via channel or carrier protein - passive transport - small particles

Active Transport

- small molecules - move against concentration gradient - combining with carrier proteins - requires energy

How many NADH are produced by glycolysis? a. 4 b. 2 c. 3 d. 5 e. 1

2

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? a. 4 b. 2 c. 3 d. 1 e. 5

3

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? a. 4 b. 10 c. 6 d. 2 e. 8

6

Which of the following equations represents photosynthesis? a. 6CO2 + 6H2O → C6H12O6 + 6O2 b. C6H12O6 + 6O2 → 6CO2 + 6H2O c. 6CO2 + 6O2 → C6H12O6 + 6H2O d. 6H2O + 6O2 → C6H12O6 + 6CO2 e. C6H12O6 + 6CO2 → 6O2 + 6H2O

6CO2 + 6H2O → C6H12O6 + 6O2

Why does the relationship between metabolic rate and temperature exist? a. Cellular respiration requires organisms to take in heat energy. b. A by-product of cellular respiration is heat. c. Cellular respiration causes the body to cool because all the energy is used to make ATP.

A by-product of cellular respiration is heat.

What two molecules are produced by the light reactions and used to power the Calvin cycle? a. C6H12O6 and RuBP b. CO2 and O2 c. C6H12O6 and O2 d. G3P and H2O e. ATP and NADPH

ATP and NADPH

Which of the following statements regarding active transport is false? a. Active transport uses ATP as an energy source b. Active transport can move a solute against its concentration gradient. c. Active transport requires the cell to expend energy d. Active transport is driven by the concentration gradient

Active transport is driven by the concentration gradient

Which of the following statements regarding active transport is false? a. Active transport uses ATP as an energy source. b. Active transport can move a solute against its concentration gradient. c. Active transport requires the cell to expend energy. d. Active transport is driven by the concentration gradient.

Active transport is driven by the concentration gradient.

Which of the following statements regarding thermodynamics is false? a. Thermodynamics is the study of energy transformations that occur in a collection of matter. b. A single cell or the planet Earth could be a thermodynamic system. c. An open system exchanges both energy and matter with its surroundings. d. An automobile engine is a closed system because it does not exchange energy and matter with its surroundings.

An automobile engine is a closed system because it does not exchange energy and matter with its surroundings.

What connects the two photosystems in the light reactions? a. A chain of glucose molecules b. The Calvin cycle c. Chlorophyll d. A thylakoid e. An electron transport chain

An electron transport chain

Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____. a. B ... the oxygen molecules inside cell B have a higher kinetic energy b. A ... its membrane transport proteins will not be saturated c. B ... the diffusion gradient there is steeper d. A ... the diffusion gradient there is shallower

B ... the diffusion gradient there is steeper

Many of the regions of the world where hunger is prevalent are also regions with hot and dry climates. What types of agricultural crops would you suggest that these regions attempt to grow? a. C3 plants, such as wheat and rice b. C3 plants and C4 plants, such as corn and sugarcane c. C3 plants and CAM plants, such as prickly pear and pineapple d. C4 plants and CAM plants

C4 plants and CAM plants

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle? a. G3P (C3H6O3) b. RuBP c. Sucrose (C12H22O11) d. Carbon dioxide (CO2) e. Glucose (C6H12O6)

Carbon dioxide (CO2)

In plant cells, carbon dioxide and water are joined to form carbohydrates. Plant cells can also break down carbohydrates such as glucose, releasing carbon dioxide, water, and energy. No one has ever observed such reactions between water and carbon dioxide outside of living cells. What allows simple molecules to assemble into more complex molecules, and also disassemble, in cells but not in other, nonbiological environments? a. Cells possess properties not seen in nonliving things, which allow them to run physical processes in reverse. b. Cells couple energy-releasing reactions to energy-requiring reactions. c. Cells are far more efficient in energy transactions than are nonliving substances. d. Cells are subject to only the first law, not the second law, of thermodynamics.

Cells couple energy-releasing reactions to energy-requiring reactions.

Why are most plants green? a. Chlorophyll a reflects green light b. Chlorophyll a absorbs green light c. Chlorophyll b primarily uses green light as the source of energy for photosynthesis d. Green helps plants blend into their environment as a sort of camouflage

Chlorophyll a reflects green light

In which of the following organelles does photosynthesis take place? a. Central vacuole b. Chloroplast c. Ribosome d. Mitochondrion e. Nucleus

Chloroplast

Which of the following statements regarding diffusion is false? a. Diffusion is a result of the thermal energy of atoms and molecules. b. Diffusion occurs even after equilibrium is reached and no net change is apparent. c. Diffusion requires no input of energy into the system. d. Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action? a. Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell. b. Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions. c. Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. d. Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions.

Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

The Calvin cycle constructs ________, an energy-rich molecule that a plant cell can then use to make glucose or other organic molecules. a. carbon dioxide b. ATP c. G3P d. NADH

G3P

The antibiotic oligomycin works by inhibiting ATP synthase. You would expect that a. there will be an increase in ATP production. b. H+ will accumulate in the intermembrane space. c. H+ will accumulate in the mitochondrial matrix. d. NAD+ and FAD will pick up the extra H+.

H+ will accumulate in the intermembrane space.

In photophosphorylation, energy from electron flow is used to transport ________ from the ________ to the thylakoid compartment, generating a concentration gradient of ________. a. electrons; grana; H+ b. H+; grana; electrons c. H+; stroma; H+ d. H+; stroma; ATP

H+; stroma; H+

What provides electrons for the light reactions? a. O2 b. H2O c. Light d. CO2 e. The Calvin cycle

H2O

The Pasteur effect shows that yeasts consume glucose at a higher rate under anaerobic conditions than under aerobic conditions. Which of the following statements correctly explains this observation? a. Yeasts are obligate anaerobes, so aerobic conditions will kill yeasts. b. Yeasts are photosynthetic, so they are able to produce their own oxygen c. Less ATP is made under anaerobic conditions, so more glucose must be consumed to produce an equivalent amount of ATP

Less ATP is made under anaerobic conditions, so more glucose must be consumed to produce an equivalent amount of ATP

Which of the following statements regarding membrane protein function is false? a. Membrane proteins serve as enzymes. b. Membrane proteins act as receptors to molecules like hormones. c. Membrane proteins form junctions between cells. d. Membrane proteins produce phospholipids

Membrane proteins produce phospholipids

________ cells in leaves are specialized for photosynthesis. a. Stomata b. Vein c. Mesophyll

Mesophyll

In the absence of oxygen, cells need a way to regenerate which compound? a. NAD+ b. ethanol c. carbon dioxide d. lactic acid

NAD+

At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in a. CO2 b. pyruvate c. ATP d. NADH

NADH

The end products of glycolysis include a. NADH b. acetyl CoA c. citric acid d. O2

NADH

As a result of the cascade of electrons moving down the electron transport chain and leaving the light reactions a. NADPH is reduced to NADP+ b. NADPH is oxidized to NADP+ c. NADP+ is reduced to NADPH d. NADP+ is oxidized to NADPH

NADP+ is reduced to NADPH

After 3-PGA is phosphorylated, it receives energized electrons from _____. a. ATP b. CO2 c. ADP d. NADP+ e. NADPH

NADPH

What transports electrons from the light reactions to the Calvin cycle? a. NADPH b. FADH2 c. An electron transport chain d. NADH e. Chlorophyll

NADPH

Which of the following statements regarding photosynthesis and cellular respiration is true? a. Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria. b. Photosynthesis occurs in mitochondria, and cellular respiration occurs in chloroplasts. c. Photosynthesis occurs in mitochondria and in chloroplasts. d. Cellular respiration occurs in mitochondria and in chloroplasts.

Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria.

Carbon fixation involves the addition of carbon dioxide to _____. a. RuBP b. NADPH c. Rubisco d. 3-PGA e. G3P

RuBP

Marathon runners are long-distance runners (marathons are races that are 26.2 miles long). Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch muscle cells. Which of the following statements about these fibers is true? a. Slow-twitch fibers have lots of mitochondria to make ATP aerobically. b. Slow-twitch fibers have lots of mitochondria to make ATP through fermentation c. Slow-twitch fibers have few mitochondria and make ATP aerobically. d. Slow-twitch fibers have few mitochondria and make ATP through fermentation

Slow-twitch fibers have lots of mitochondria to make ATP aerobically.

Which of the following statements regarding membrane function is false? a. The plasma membrane forms a selective barrier around the cell. b. The plasma membrane plays a role in transferring signals to the cell's interior. c. The plasma membrane has receptors for chemical messages. d. The plasma membrane is the control center of the cell.

The plasma membrane is the control center of the cell.

Which of the following is a typical feature of an ATP-driven active transport mechanism? a. The transport protein must cross to the correct side of the membrane before the solute can bind to it. b. The transport protein is irreversibly phosphorylated as transport takes place. c. The transport protein catalyzes the conversion of ADP to ATP. d. The solute moves against the concentration gradient.

The solute moves against the concentration gradient.

How do cells capture the energy released by cellular respiration? a. They produce ATP b. They produce glucose c. They store energy in molecules of carbon dioxide d. The energy is coupled to oxygen

They produce ATP

The function of coenzyme A in the citric acid cycle is most like a. a limousine driver dropping off a couple at the school prom. b. throwing a baited hook into a lake and catching a fish. c. a kid jumping up and down on a trampoline. d. a frog that turns into a prince.

a limousine driver dropping off a couple at the school prom.

Which of the following processes produces the most ATP per molecule of glucose oxidized? a. aerobic respiration b. alcoholic fermentation c. lactic acid fermentation

aerobic respiration

Membrane phospholipids a. have hydrophilic tails that face outward and are exposed to water. b. are able to drift about in the plasma membrane. c. remain fluid because they are tightly packed against one another. d. have hydrophobic heads that face the center of the membrane and are shielded from water.

are able to drift about in the plasma membrane.

A plant cell in a hypotonic solution a. becomes turgid because of an inflow of water b. bursts because of an inflow of water. c. shrivels because of an outflow of water d. wilts because of an outflow of water

becomes turgid because of an inflow of water

A plant cell in a hypotonic solution a. becomes turgid because of an inflow of water. b. bursts because of an inflow of water. c. shrivels because of an outflow of water. d. wilts because of an outflow of water.

becomes turgid because of an inflow of water.

Endocytosis

cells engulf substances into pouch which becomes a vesicle

In most green plants, chloroplasts are a. concentrated in a zone of leaf tissue called the mesophyll. b. concentrated in a portion of the leaf called the stroma. c. evenly distributed throughout the leaf tissue. d. evenly distributed throughout the entire plant.

concentrated in a zone of leaf tissue called the mesophyll.

Which of the following is a result of glycolysis? a. production of CO2 b. conversion of glucose to two three-carbon compounds c. a net loss of two ATPs per glucose molecule d. conversion of NADH to NAD+

conversion of glucose to two three-carbon compounds

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. a. thylakoids b. grana c. stroma d. stoma e. cytoplasm

cytoplasm

Living systems a. violate the first law of thermodynamics. b. violate the second law of thermodynamics. c. decrease their entropy while increasing the entropy of the universe. d. are examples of a closed system.

decrease their entropy while increasing the entropy of the universe.

The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, __________. a. NADH is reduced as it donates electrons to the first complex involved in the electron transport chain b. ATP synthase allows hydrogen ions to move across the mitochondrial membrane c. all the carriers pump H+ across the mitochondrial membrane, forming a gradient that is used to drive ATP synthesis d. electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane

electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane

Photosynthesis is an __________ process in which carbon is __________, whereas cellular respiration is an __________ process in which carbon is __________. a. endergonic : reduced : exergonic : oxidized b. endergonic : oxidized : exergonic : reduced c. endergonic : oxidized : endergonic : reduced d. exergonic : reduced : endergonic : oxidized

endergonic : reduced : exergonic : oxidized

ATP can be used as the cell's energy exchange mechanism because a. endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP b. ATP is the most energy-rich small molecule in the cell. c. endergonic reactions can be fueled by coupling them with the formation of ATP from ADP. d. ATP is a disposable form of chemical energy, used once and then discarded by the cell.

endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP

Which of the following are products of cellular respiration? a. oxygen and carbon dioxide b. energy to make ATP and carbon dioxide and water c. oxygen and glucose d. oxygen and energy to make ATP

energy to make ATP and carbon dioxide and water

Which of the following are products of cellular respiration? a. oxygen and energy to make ATP b. energy to make ATP and carbon dioxide and water c. oxygen and glucose d. oxygen and carbon dioxide

energy to make ATP and carbon dioxide and water

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction. a. endergonic; exergonic b. exergonic; spontaneous c. exergonic; endergonic d. spontaneous; exergonic

exergonic; endergonic

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction. a. exergonic; endergonic b. endergonic; exergonic c. exergonic; spontaneous d. spontaneous; exergonic

exergonic; endergonic

The function of cellular respiration is to _____. a. synthesize macromolecules from monomers b. extract CO2 from the atmosphere c. reduce CO2 d. extract usable energy from glucose

extract usable energy from glucose

Pyruvate a. is the molecule that starts the citric acid cycle. b. is a six-carbon molecule. c. is the end product of oxidative phosphorylation. d. forms at the end of glycolysis.

forms at the end of glycolysis.

Which of the following molecules are products of photosynthesis? a. O2 and CO2 b. glucose and O2 c. glucose and CO2 d. CO2 and chlorophyll

glucose and O2

Which of the following direct energy transfers is impossible in living systems? a. light energy to chemical energy b. chemical energy to kinetic energy c. light energy to potential energy d. heat to light energy

heat to light energy

Where does glycolysis occur in a eukaryotic cell? a. within the intermembrane space of the mitochondrion b. in the cytoplasmic fluid c. on the inner mitochondrial membrane d. in the mitochondria

in the cytoplasmic fluid

Tonicity

is a term that describes the ability of a surrounding solution to cause a cell to gain or lose water

Respiration ________, and cellular respiration ________. a. produces ATP; is gas exchange b. is gas exchange; produces ATP c. produces glucose; produces oxygen d. uses glucose; produces glucose

is gas exchange; produces ATP

A cell that has neither a net gain of water nor a net loss of water when it is immersed in a solution must be a. isotonic to its environment. b. hypertonic to its environment. c. hypotonic to its environment.

isotonic to its environment.

When an enzyme catalyzes a reaction, a. it is used once and discarded. b. it raises the activation energy of the reaction. c. it lowers the activation energy of the reaction. d. it acts as a reactant.

it lowers the activation energy of the reaction.

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to __________. a. thermal energy and heat b. potential energy and heat c. kinetic energy and heat d. ATP and heat

kinetic energy and heat

A child is born with a rare disease in which mitochondria are missing from skeletal muscle cells. However, the muscles still function. Physicians find that the a. muscles contain large amounts of lactate following even mild physical exercise. b. muscles contain large amounts of carbon dioxide following even mild physical exercise. c. muscles require extremely high levels of oxygen to function. d. muscle cells cannot split glucose to pyruvate.

muscles contain large amounts of lactate following even mild physical exercise.

You're on the pilot episode of a new game show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____. a. five b. nine c. three d. one

nine

Oxidation is the ________, and reduction is the ________. a. gain of protons; loss of protons b. gain of oxygen; loss of oxygen c. loss of electrons; gain of electrons d. gain of electrons; loss of electrons

oss of electrons; gain of electrons

Clusters of light-gathering pigments in a photosystem a. pass energy to the reaction center. b. are found in the roots of plants. c. absorb electrons. d. break down H2O.

pass energy to the reaction center.

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of a. exocytosis. b. passive transport. c. active transport. d. endocytosis

passive transport.

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of a. exocytosis. b. passive transport. c. active transport. d. endocytosis.

passive transport.

In chloroplasts, ATP synthase a. phosphorylates ADP to ATP. b. is found in the stroma. c. catalyzes the Calvin cycle. d. helps produce the concentration gradient of H+.

phosphorylates ADP to ATP.

The transfer of a phosphate group to a molecule or compound is called a. carboxylation. b. ionization. c phosphorylation. d. hydrogenation

phosphorylation

Autotrophs that utilize light as their energy source are a. chemosynthetic autotrophs. b. photoautotrophs. c. fungi d. heterotrophs

photoautotrophs.

Autotrophs that utilize light as their energy source are a. chemosynthetic autotrophs. b. photoautotrophs. c. heterotrophs. d. fungi.

photoautotrophs.

A packet of light energy is called a a. quantum. b. pigment. c. photon d. phaser

photon

In C3 plants the conservation of water promotes _____. a. photosynthesis b. a shift to C4 photosynthesis c. the opening of stomata d. the light reactions e. photorespiration

photorespiration

The addition of oxygen instead of carbon dioxide to RuBP results in a. cellular respiration b. photorespiration c. photophosphorylation d. aerobic respiration

photorespiration

The addition of oxygen instead of carbon dioxide to RuBP results in a. cellular respiration. b. photorespiration. c. photophosphorylation. d. aerobic respiration.

photorespiration.

The ultimate source of all the food we eat and the oxygen we breathe is a. cellular respiration. b. photosynthesis. c. glycolysis. d. anaerobic metabolism.

photosynthesis.

What is the likely origin of chloroplasts? a. eukaryotes that engulfed photosynthetic fungi b. mitochondria that had a mutation for photosynthesis c. photosynthetic prokaryotes that lived inside eukaryotic cells d. prokaryotes with photosynthetic mitochondria

photosynthetic prokaryotes that lived inside eukaryotic cells

Most of a cell's enzymes are a. lipids. b. proteins. c. amino acids. d. carbohydrates

proteins.

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by a. glycolipids. b. proteins. c. phospholipids. d. cholesterol.

proteins.

The molecules responsible for membrane transport are a. steroids. b. phospholipids. c. carbohydrates. d. proteins.

proteins.

After glycolysis but before the citric acid cycle a. pyruvate is oxidized. b. a carbon atom is added to pyruvate to make a four-carbon compound c. coenzyme A is cleaved off pyruvate d. glucose is split, producing two molecules of pyruvate

pyruvate is oxidized.

After glycolysis but before the citric acid cycle, a. a carbon atom is added to pyruvate to make a four-carbon compound. b. glucose is split, producing two molecules of pyruvate. c. pyruvate is oxidized. d. coenzyme A is cleaved off pyruvate.

pyruvate is oxidized.

Which of the following enables a cell to pick up and concentrate a specific kind of molecule? a. receptor-mediated endocytosis b. osmosis c. passive transport d. diffusion

receptor-mediated endocytosis

Cells acquire low-density lipoproteins (LDLs) by a. diffusion. b. receptor-mediated endocytosis. c. exocytosis. d. phagocytosis.

receptor-mediated endocytosis.

Glycolysis is the only stage of cellular respiration that __________. a. does not release carbon dioxide as a by-product b. requires ATP to make ATP c. does not require ATP to make ATP d. requires oxygen to function

requires ATP to make ATP

Anything that prevents ATP formation will most likely a. result in cell death. b. force the cell to rely on lipids for energy. c. force the cell to rely on ADP for energy. d. have no effect on the cell.

result in cell death.

An electron transport chain of the light reactions a. is located in the stroma. b. shuttles electrons from photosystem II to photosystem I. c. provides energy for the citric acid cycle. d. is found on the plasma membrane of mesophyll cells.

shuttles electrons from photosystem II to photosystem I

CO2 enters and O2 escapes from a leaf via a. grana b. stroma c. thylakoids d. stomata

stomata

In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called the a. stomata. b. thylakoid c. matrix d. stroma.

stroma.

In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called the a. thylakoid. b. stomata. c. stroma. d. matrix.

stroma.

All cells are enclosed by a plasma membrane that is similar in ________ and ________. a. permeability; content b. lucidity; texture c. thickness; composition d. structure; function

structure; function

Osmosis can be defined as a. the diffusion of water. b. the diffusion of nonpolar molecules. c. active transport. d. the diffusion of a solute.

the diffusion of water.

Which of the following processes is classified as a metabolic pathway? a. the synthesis of a protein b. water moving across a membrane via osmosis c. the death and lysis of a cell d. the movement of oxygen across a membrane

the synthesis of a protein

Which of the following processes is endergonic? a. the burning of wood b. the synthesis of glucose from carbon dioxide and water c. the breakdown of glucose d. cellular respiration

the synthesis of glucose from carbon dioxide and water

Where is chlorophyll found in a plant cell? a. stroma b. thylakoid membranes c. cytoplasm d. cristae

thylakoid membranes

The light reactions take place in the _________ and the Calvin cycle takes place in the _________. a. thylakoids; stroma b. chloroplasts; mitochondria c. inner membrane; outer membrane d. stroma; thylakoids e. mitochondria; chloroplasts

thylakoids; stroma

C4 plants differ from C3 and CAM plants in that C4 plants _____. a. use PEP carboxylase to fix carbon dioxide b. transfer fixed carbon dioxide to cells in which the Calvin cycle occurs c. use malic acid to transfer carbon dioxide to the Calvin cycle d. open their stomata only at night e. are better adapted to wet conditions

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient. a. energy and transport proteins; down b. transport proteins; down c. energy and transport proteins; against d. transport proteins; against

transport proteins; down

Exocytosis

vesicles fuse with plasma membrane and secrete contents

Aquaporins are proteins that facilitate the transport of __________ across the membrane a. water b. urine c. salt d. proteins

water

Where do the electrons needed by photosystem II originate? a. water b. other chlorophyll molecules c. ATP d. the electron transport chain

water

Which of the following organisms can make organic molecules from water and carbon dioxide? a. bear b. mushroom c. wheat d. crayfish

wheat

You are adrift in the Atlantic Ocean and, being thirsty, drink the surrounding seawater. As a result a. you quench your thirst b. your cells become turgid c. you dehydrate yourself d. your cells lyse from excessive water intake

you dehydrate yourself