Exam 2

In the reaction at the end of the electron transport chain, molecule X is being _ and molecule Y is being __. answerable question reference A oxidized; reduced B reduced; oxidized

A

Kinetic energy can be described as energy in motion. Which of the following is NOT an example of kinetic energy? A the energy in chemical bonds B sound C heat D light E random molecular movement

A

Label each of the following systems as high or low entropy: i. the instant that a perfume bottle is sprayed compared with 30 seconds later, ii. an old 1950s car compared with a brand new car, and iii. a living cell compared with a dead cell. A i. low, ii. high, iii. low B i. low, ii. high, iii. high C i. high, ii. low, iii. high D i. high, ii. low, iii. Low

A

Main characteristics of active transport are that it requires energy and often moves molecules against their concentration gradient. A true B false

A

Photosynthesis is A Endergonic B Exergonic

A

Which one of these is NOT correct about cell membrane in animals A It is made of phospholipid bilayer B It contains proteins C It contains cholesterol D contains glycoproteins and glycolipids on the internal side E Glycoproteins and glycolipids are important for cell recognition and signaling F

D

Which one of these is NOT passive transport? A Osmosis B Diffusion C Facilitated diffusion D Infusion

D

How does a plant cell use the ATP that it produces in the light reactions? A to fuel processes and reactions throughout the cell B to fuel the Calvin cycle C to break down glucose D to convert NADP+ to NADPH E to fuel Krebs cycle

B

How does a plant cell use the ATP that it produces in the light reactions? A to fuel processes and reactions throughout the cell B to fuel the carbon reactions C to break down glucose D to convert NADP+ to NADPH

B

You look at the electromagnetic spectrum chart and realize that the frequency of AM radio waves is 106 Hz and frequency of UV rays is 1016 Hz. Which one of following statements is NOT true regarding AM radio waves and UV rays? A UV rays have lower wavelength than AM radio waves B UV rays are more harmful to us than AM radio waves C UV rays have higher energy than AM radio waves D UV waves have higher wavelength than AM radio waves

D

What happens to the membrane of a vesicle after exocytosis? A It leaves the cell. B It is disassembled by the cell. C It fuses with and becomes part of the plasma membrane. D It is used again in another exocytosis event.

C

Active transport must function continuously because __________. A plasma membranes wear out B not all membranes are amphiphilic C facilitated transport opposes active transport D diffusion is constantly moving solutes in opposite directions

D

What is the combination of an electrical gradient and a concentration gradient called? A potential gradient B electrical potential C concentration potential D electrochemical gradient

D

Which characteristic of a phospholipid contributes to the fluidity of the membrane? A its head B cholesterol C a saturated fatty acid tail D double bonds in the fatty acid tail

D

Which of the following comparisons or contrasts between endergonic and exergonic reactions is false? A Endergonic reactions have a positive ∆G and exergonic reactions have a negative ∆G B Endergonic reactions consume energy and exergonic reactions release energy C Both endergonic and exergonic reactions require a small amount of energy to overcome an activation barrier D Endergonic reactions take place slowly and exergonic reactions take place quickly

D

During glycolysis molecules of glucose are A broken down into three molecules of pyruvate. B bonded covalently to form two molecules of pyruvate. C broken down in oxidation, and releasing carbon atoms as CO2. D bonded by enzymes to form three molecules of pyruvate. E broken down by enzymes to form two molecules of pyruvate.

E

ATP contains __ energy. A Potential B Kinetic

A

Cell membrane is fluid mosaic and not a solid structure. A True B False

A

DNA replication involves unwinding two strands of parent DNA, copying each strand to synthesize complementary strands, and releasing the parent and daughter DNA. Which of the following accurately describes this process? A This is an anabolic process B This is a catabolic process C This is both anabolic and catabolic D This is a metabolic process but is neither anabolic nor catabolic

A

During photosynthesis, O2, if present in concentrations higher than CO2 , can bind to Rubisco's active site and cause photorespiration. A negative feedback; competitive inhibition B positive feedback; competitive inhibition C negative feedback; noncompetitive inhibition D positive feedback; noncompetitive inhibition

A

Glucose contains _ energy. A potential B kinetic

A

How do the light reactions produce ATP? (Select the one best answer.) A Potential energy stored in a hydrogen ion gradient is used to synthesize ATP. B Photosystem I directly adds a phosphate to ADP. C Photosystem II directly adds a phosphate to ADP. D Energy released by electrons is directly used to synthesize ATP.

A

How does electron transport chain in cell respiration produce ATP? (Select the one best answer.) A Potential energy stored in a hydrogen ion gradient is used to synthesize ATP. B Photosystem I directly adds a phosphate to ADP. C Photosystem II directly adds a phosphate to ADP. D Energy released by electrons is directly used to synthesize ATP.

A

In a typical plant leaf, the ____ are where photosynthesis takes place. A mesophyll cells B stromata C outer epidermis cells D air spaces E stomata

A

Photosynthesis is ____ reaction. CO2 gains electrons so it is being ____ and H2O looses electrons so it is being _____ . answerable question reference A Endergonic; reduced; oxidized B Exergonic; oxidized; reduced C Endergonic; oxidized; reduced D Exergonic; reduced; oxidized

A

Plants produce oxygen when they photosynthesize. Where does the oxygen come from? A splitting water molecules B ATP synthesis C the electron transport chain D chlorophyll

A

The energy currency used by cells is ​ \text{ ________ } ​ A ATP B ADP C AMP D adenosine

A

What is the primary function of carbohydrates attached to the exterior of cell membranes? A identification of the cell B flexibility of the membrane C strengthening the membrane D channels through membrane

A

What problem is faced by organisms that live in fresh water? A Their bodies tend to take in too much water. B They have no way of controlling their tonicity. C Only salt water poses problems for animals that live in it. D Their bodies tend to lose too much water to their environment.

A

When NADP+ ____ in the light cycle it is ____, forming NADPH. A accepts electrons; reduced B accepts electrons; stabilized C accepts electrons; oxidized D donates electrons; oxidized E donates electrons; reduced

A

Which of the following analogies best describe the induced-fit model of enzyme-substrate binding? A A hug between two people B A key fitting into a lock C A square peg fitting through the square hole and a round peg fitting through the round hole of a children's toy D The fitting together of two jigsaw puzzle pieces.

A

Which of the following is not an example of an energy transformation? A Turning on a light switch B Solar panels at work C Formation of static electricity D None of the above

A

Which of the following is not true about enzymes: A They increase ∆G of reactions B They are usually made of amino acids C They lower the activation energy of chemical reactions D Each one is specific to the particular substrate(s) to which it binds

A

Which of the following is not true about enzymes? A They are consumed by the reactions they catalyze. B They are usually made of amino acids. C They lower the activation energy of chemical reactions. D Each one is specific to the particular substrate(s) to which it binds.

A

Which of the following molecules is likely to have the most potential energy? A sucrose B ATP C glucose D ADP

A

Which one of these is exergonic? A ATP + H2O ==> ADP + Pi + Energy B

A

Which one of these is exergonic? A ATP + H2O ==> ADP + Pi + Energy B ADP + Pi + Energy ==> ATP

A

Which plasma membrane component can be either found on its surface or embedded in the membrane structure? A protein B cholesterol C carbohydrate D phospholipid

A

Which statement correctly describes carbon fixation? A the conversion of CO2 to an organic compound B the use of RUBISCO to form 3-PGA C the production of carbohydrate molecules from G3P D the formation of RuBP from G3P molecules E the use of ATP and NADPH to reduce CO2

A

Why does fermentation yield so much less ATP? A it only goes through glycolysis B stops after transitional step C stops at Krebs cycle D goes through all steps but because of lack of O2, it spends all made ATP

A

Which of the following is not an example of an energy transformation? A Heating up dinner in a microwave B Solar panels at work C Formation of static electricity D None of the above

A & D

Which one of these is correct? (choose all that apply) Multiple answers: You can select more than one option A when animal cell is placed in hypotonic solution it might explode (lyse) due to water intake B when animal cell is placed in hypotonic solution it might shrink due to loss of water C when plant cell is placed in hypotonic solution it might explode (lyse) due to water intake D when plant cell is placed in hypotonic solution it might shrink due to loss of water E Plant cells are protected from lyses or shrinkage by cell wall

A & E

From where does a heterotroph directly obtain its energy? A the sun B the sun and eating other organisms C eating other organisms D simple chemicals in the environment

C

Cell respiration is ____ reaction. Glucose looses electrons so it is being ____ and O2 is gaining electrons so it is being _____ . answerable question reference A Endergonic; reduced; oxidized B Exergonic; oxidized; reduced C Endergonic; oxidized; reduced D Exergonic; reduced; oxidized

B

Compared to the air a person inhales, the air that they exhale has A lower concentrations of both O2 and CO2. B a lower concentration of O2 and a higher concentration of CO2. C higher concentrations of both O2 and CO2. D a higher concentration of O2 and a lower concentration of CO2. E equal amounts of O2 and CO2.

B

If concentration of solute in cell is 34% and outside is 88%, water will A move into the cell because cell is in hypertonic environment B move out of the cell because cell is in hypertonic environment C move into the cell because cell is in hypotonic environment D move out of the cell because cell is in hypotonic environment E nothing will happen because cell is in isotonic environment

B

Main differences between active and passive transport are that passive transport requires energy and transports molecules down their concentration gradient. A True B False

B

On a class field trip, students swabbed, dug, and dipped samples of life from numerous places around campus. Back in the lab, one of the organisms found was unknown to the professor, or any reference books available, and could not be identified. It came from the edge of a marsh, and the sample smelled of hydrogen sulfide (rotten eggs). The single cells were found to survive only in a container that had sulfate in it, but also had the oxygen removed by burning a candle (so instead of O2, S is the acceptor of electrons). This is likely an organism that uses ____ for cellular respiration. A only glycolysis B anaerobic respiration C aerobic respiration D lactic acid fermentation E alcohol fermentation

B

Plants do not need cell respiration A true B false

B

Reduction means A the loss of electrons by a molecule. B the gain of electrons by a molecule C the gain of oxygen and an electron. D the gain of oxygen by a cell. E the loss of oxygen from a cell.

B

Simple diffusion A utilizes proteins to move molecules across a membrane. B does not require energy. C cannot occur without a membrane present. D requires energy. E moves molecules against a concentration gradient.

B

Some photosynthetic bacteria have chloroplasts. A True B False

B

The reactions of photosynthesis may be summarized as A 12CO2 + 6H2O → C12H12O6 + 6H2O B 6CO2 + 6H2O → C6H12O6 + 6O2 C 6CO + 6H2O → C6H12O6 + 6H2O D 6CO + 6H2O → C6H12O6 + 6O2

B

The sodium-potassium pump moves K+ into the cell while moving Na+ out at the same time, at a ratio of 3 Na+ for every 2 K+ ions moved in. K+ and Na+ are moving down their concentration gradients. A True B false

B

The survival of most organisms is immediately threatened if they live at the site of a catastrophic forest fire, volcanic eruption, or dust storm. These events, however, can launch soot, ash, or dust into different levels of the atmosphere, measurably lowering available sunlight at locations thousands of miles from the site. The ____ are most quickly and strongly impacted at these distances, with lack of growth and reproduction. A heterotrophs, such as humans and livestock B autotrophs, such as crops and woodlands C deep-sea thermal vent communities D All of the answer choices are correct. E All of the organisms in domain Bacteria.

B

What is the energy of a photon first used to do in photosynthesis? A split a water molecule B energize an electron C produce ATP D synthesize glucose

B

What is the molecule that leaves the Calvin cycle to be converted into glucose? A ADP B G3P C RuBP D 3-PGA

B

Which color(s) of light does chlorophyll a reflect? A red and blue B green C red D blue

B

Which of the following is the best way to judge the relative activation energies between two given chemical reactions? A Compare the ∆G values between the two reactions B Compare their reaction rates C Compare their ideal environmental conditions D Compare the spontaneity between the two reactions

B

Which one of these statements is NOT true about photosynthesis? A Calvin cycle is independent of light B Goal of photosynthesis is to produce O2 C Some bacteria can photosynthesize D In some plants, Calvin cycle does not occur in same cells as light

B

Which statement about thylakoids in eukaryotes is not correct? A Thylakoids are assembled into stacks. B Thylakoids exist as a maze of folded membranes. C The space surrounding thylakoids is called stroma. D Thylakoids contain chlorophyll.

B

Which step of cell respiration DOES NOT produce ATP A Glycolysis B Transitional Step C Krebs cycle D Electron transport chain

B

Which transport mechanism can bring whole cells into a cell? A pinocytosis B phagocytosis C facilitated transport D primary active transport

B

Glycolysis occurs in the A mitochondria. B nucleus. C cytoplasm. D lysosome. E cell membrane.

C

An allosteric inhibitor does which of the following? A Binds to an enzyme away from the active site and changes the conformation of the active site, increasing its affinity for substrate binding B Binds to the active site and blocks it from binding substrate C Binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate D Binds directly to the active site and mimics the substrate

C

At the end of the electron transport chain in light reactions of photosynthesis, NADP+ 2 electrons and turns into NADPH. We say that NADP+ is being . A Accepts; oxidized B Releases; oxidized C Accepts; reduced D Releases; reduced

C

Consider a pendulum swinging. Which type(s) of energy is/are associated with the pendulum in the following instances: i. the moment at which it completes one cycle, just before it begins to fall back towards the other end, ii. the moment that it is in the middle between the two ends, iii. just before it reaches the end of one cycle (just before instant i.). A i. potential and kinetic, ii. potential and kinetic, iii. kinetic B i. potential, ii. potential and kinetic, iii. potential and kinetic C i. potential, ii. kinetic, iii. potential and kinetic D i. potential and kinetic, ii. kinetic iii. kinetic

C

During photosynthesis light reactions, water is needed to __. A Release O2 into atmosphere B To receive electrons from photosystem II C To replace electrons knocked out of photosystem II by light photon D Because otherwise plant will dry out

C

Energy is stored long-term in the bonds of ____ and used short-term to perform work from a(n) ____ molecule. A ATP : glucose B an anabolic molecule : catabolic molecule C glucose : ATP D a catabolic molecule : anabolic molecule

C

How does the sodium-potassium pump make the interior of the cell negatively charged? A by expelling anions B by pulling in anions C by expelling more cations than are taken in D by taking in and expelling an equal number of cations

C

If a cell has a greater concentration of solute than its environment, the cell A will not experience a net gain or loss of water. B will die. C is hypertonic to the environment. D is hypotonic to the environment. E is isotonic to the environment.

C

In what important way does receptor-mediated endocytosis differ from phagocytosis? A It transports only small amounts of fluid. B It does not involve the pinching off of membrane. C It brings in only a specifically targeted substance. D It brings substances into the cell, while phagocytosis removes substances.

C

Plants require a lot of water for hydration, metabolism, homeostasis, and photosynthesis. How is water used in photosynthesis? A as an electron acceptor in the electron transport chain B as a substrate for ATP synthase C as an electron donor in the photosystems D to combine with NADP+ to form NADPH E to combine with ADP to form ATP

C

The organelle that carries out photosynthesis in plants is the A chlorophyll. B lysosome. C chloroplast. D mitochondria. E ribosome.

C

The principal force driving movement in diffusion is the __________. A temperature B particle size C concentration gradient D membrane surface area

C

Up to 25% of a cell's ATP is used to run sodium-potassium pumps. Without the resulting sodium and potassium gradients, neurons and muscles cannot fire properly. The sodium-potassium pump requires energy and moves these ions against their concentration gradients. As such, sodium-potassium pump represents A diffusion. B osmosis. C active transport. D facilitated diffusion. E equilibrium.

C

Water moves via osmosis __________ A throughout the cytoplasm B from an area with a high concentration of other solutes to a lower one C from an area with a high concentration of water to one of lower concentration D from an area with a low concentration of water to one of higher concentration

C

What two products result from photosynthesis? A water and carbon dioxide B water and oxygen C glucose and oxygen D glucose and carbon dioxide

C

Where in plant cells does the Calvin cycle take place? A thylakoid membrane B thylakoid space C stroma D granum

C

Which molecule absorbs the energy of a photon in photosynthesis? A ATP B glucose C chlorophyll D water

C

Which of the following pathways would be used for photosynthesis by a cactus found in the desert? A Krebs cycle B C4 pathway C CAM pathway D C3 pathway E All of the answer choices are correct.

C

Which one of these is NOT correct regarding Calving cycle? A During phase 1, ribulose binds (fixates) CO2 with use of Rubisco enzyme B During phase 2, unstable 6-carbon molecule is reduced into stable 3-carbon molecules C During phase 3, rubisco is recycled D It takes 2 full Calvin cycles to produce 1 molecule of glucose

C

Which one of these is correct pairing between type of plants and location/time of CO2 fixation? A C4 plants - fixate CO2 during night in bundle sheath cells B C3 plants - fixate CO2 during night in bundle sheath cells C CAM plants - fixate CO2 during night in mesophyll cells D All of these are correct E None of these is correct

C

Which one of these is not part of Cell respiration A Glycolysis B Transitional step C Calvin cycle D Krebs cycle E Electron transport chain

C

According to the graph, at what temperature do you predict the bacterial enzyme becomes denatured? answerable question reference A 55°C B 66°C C 70°C D 75°C

D

Why are leaves green? A Heterotrophs see green better than any other color. B Plant pigments absorb green light. C Plant pigments absorb almost every wavelength except for green. D Plant pigments change yellow light that they absorb to green light that we see.

C

Why does the sodium-potassium pump require energy? Refer to the image below. answerable question reference A It uses a membrane protein. B It transports ions. C It moves solutes against their concentration gradients. D All of the choices are correct.

C

You were sitting in a park under a large tree studying for Bio1320 exam. As you were trying to memorize Power point, you gazed up into the tree above you trying to visualized how this tree was conducing photosynthesis. You realized that one part of this tree cannot conduct photosynthesis. Which part was it? A Leaves B Trunk C Roots D All of these are capable of photosynthesis E None of these are capable of photosynthesis

C

Your liver produces 90% of the cholesterol found in your body. When cholesterol levels get too high, the first enzyme in the pathway of cholesterol synthesis is inhibited by cholesterol itself. This is an example of A denaturation. B positive feedback. C negative feedback. D a coenzyme. E equilibrium.

C

The Krebs cycle produces A NADH, FADH2, and oxygen. B pyruvate and PGAL. C carbon dioxide and oxygen. D ATP, NADH, FADH2, and CO2. E oxygen and ATP.

D

The diffusion of water across a selectively permeable (biological) membrane is A a process that always requires proteins B always beneficial to a cell. C active transport. D osmosis. E a rare occurrence.

D

The energy released by the hydrolysis of ATP is A primarily stored between the alpha and beta phosphates B equal to −57 kcal/mol C harnessed as heat energy by the cell to perform work D providing energy to coupled reactions

D

The region of an enzyme that catalyzes reactions is called a(n) A cofactor site. B reaction site. C catalyst site. D active site. E binding pocket.

D

Oxidation and reduction reactions are typically linked within a cell. They are part of most matter and energy transformations necessary for vital life functions. Oxidation-reduction reactions A transfer protons from one molecule to another. B are not used by living cells. C increase the amount of oxygen in the cell. D reduce the amount of oxygen in the cell. E transfer electrons from one molecule to another.

E

The breakdown of glucose to carbon dioxide and water is an A exergonic reaction in photosynthesis. B endergonic reaction in cellular respiration. C endergonic or exergonic reaction, depending on the step. D endergonic reaction in photosynthesis. E exergonic reaction in cellular respiration.

E

The electrons removed during glycolysis and the Krebs cycle are carried to the electron transport chain by A NADH2 and glucose. B NADH and NADP. C NADP and glucose. D NADP and FADH2. E NADH and FADH2.

E

Which reaction is likely coupled with hydrolysis of ATP? A DNA synthesis B Converting proteins into amino acids C Joining monosaccharides together D A, B and C are correct E Only A and C are correct

E

Which one of these does NOT affect enzyme activity? A Temperature B pH C Enzyme concentration D Substrate concentration E Presence of cofactors F Presence of inhibitors G All of these can affect enzyme activity

G