Bio exam 2

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

How many molecules of NADH are produced during one round of glycolysis? 2 4 6 8

2

concentration gradient

A difference in the concentration of a substance across a distance.

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

Solute

A substance that is dissolved in a solution.

Which of the following statements comparing photosynthesis and cellular respiration is false? A) ATP is not produced during photosynthesis; it is produced only during cellular respiration. B) Photosynthesis is ultimately powered by light energy and respiration by the chemical energy of fuel molecules. C) Photosynthesis consumes CO2; respiration consumes O2. D) Photosynthesis produces O2; respiration produces CO2.

A) ATP is not produced during photosynthesis; it is produced only during cellular respiration.

Mitochondria transfer ________ energy from ________ to ATP; chloroplasts transform ________ energy into the chemical energy of ATP. A) chemical; food; light B) food; light; chemical C) light; food; kinetic D) food; light; nuclear

A) chemical; food; light

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will: A) exhibit a net movement to the side with lower free water concentration. B) exhibit a net movement to the side with higher free water concentration. C) exhibit a net movement to the side with lower solute concentration. D) exhibit an equal movement in both directions across the membrane.

A) exhibit a net movement to the side with lower free water concentration.

Which of the following are produced during the light reactions of photosynthesis? A) glucose, ADP, NADP+ B) glucose, ADP, NADP+, CO2 C) ADP, NADP+, O2 D) ATP, NADPH, O2

A) glucose, ADP, NADP+

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.

A) isotonic to its environment.

When an enzyme catalyzes a reaction A) it lowers the activation energy of the reaction. B) it raises the activation energy of the reaction. C) it acts as a reactant. D) it is used once and discarded.

A) it lowers the activation energy of the reaction.

In a hypotonic solution, an animal cell will A) lyse. B) experience turgor. C) neither gain nor lose water. D) shrivel.

A) lyse.

CO2 enters and O2 escapes from a leaf via A) stomata (s. stoma). B) thylakoids. C) grana. D) stroma.

A) stomata (s. stoma).

What is the source of energy that provides the boost for electrons during photosynthesis? A) sun light B) NADPH C) cellular respiration D) ATP

A) sun light

Metabolism

All of the chemical reactions that occur within an organism

________ cells in leaves are specialized for photosynthesis. A) Stomata (s. stoma) B) Mesophyll C) Vein

B) Mesophyll

Osmosis can be defined as ______. A) the diffusion of nonpolar molecules B) the diffusion of water in favor to their concentration gradient C) active transport D) the diffusion of a solute E) Endocytosis

B) the diffusion of water in favor to their concentration gradient

man with a dirty cut on his hand appears at the emergency department for treatment. In order to clean the wound, the health-care provider should use A) a solution of very low pH. B) a solution of sterilized tap water. C) a weak (low concentration) solution of salt water. D) distilled water.

C) a weak (low concentration) solution of salt water.

The transfer of a phosphate group to a molecule or compound is called A) carboxylation. B) ionization. C) phosphorylation. D) hydrogenation.

C) phosphorylation.

The active site of an enzyme is A) the region of a substrate that is changed by an enzyme. B) the highly changeable portion of an enzyme that adapts to fit the substrates of various reactions. C) the region of an enzyme that attaches to a substrate. D) the region of a product that detaches from the enzyme.

C) the region of an enzyme that attaches to a substrate.

The overall equation for the cellular respiration of glucose is C5H12O6 + 6 O2 → 5 CO2 + 6 H2O + energy. 5 CO2 + 6 H2O → C5H12O6 + 6 O2 + energy. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy. C6H12O6 + energy → 6 CO2+ 6 H2O + 6 O2.

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.

Which of the following molecules is required for photosynthesis? A) CO2 B) glucose C) O2 D) chlorophyll

CO2

Enzymes

Catalysts for chemical reactions in living things

citric acid cycle

Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.

Photosynthesis

Conversion of light energy from the sun into chemical energy.

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.

D) Active transport is driven by the concentration gradient.

Which of the following statements about ATP is true? A) It contains five phosphate groups. B) Extremely stable bonds link the second and third phosphate groups. C) It contains the sugar glucose. D) It releases energy when one phosphate group leaves ATP.

D) It releases energy when one phosphate group leaves ATP.

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.

D) The solute moves against the concentration gradient.

Which of the following processes can move a solute against its concentration gradient? A) osmosis B) passive transport C) facilitated diffusion D) active transport

D) active transport

Inhibition of an enzyme is irreversible when A) a competitive inhibitor is involved. B) a noncompetitive inhibitor is involved. C) there is an abundance of substrate. D) covalent bonds form between inhibitor and enzyme.

D) covalent bonds form between inhibitor and enzyme

Oxygen crosses a plasma membrane by A) osmosis. B) active transport. C) endocytosis. D) passive transport.

D) passive transport

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference? A) the expulsion of water by the plant cell's central vacuole B) the relative impermeability of the plant cell wall to water C) the fact that plant cells are isotonic to tap water D) the relative inelasticity and strength of the plant cell wall

D) the relative inelasticity and strength of the plant cell wall

The light reactions occur in the ________, while the Calvin cycle occurs in the ________. A) stroma; thylakoid membranes B) stroma; nucleus C) cytoplasm; thylakoid membrane D) thylakoid membranes; stroma

D) thylakoid membranes; stroma

Osmosis

Diffusion of water through a selectively permeable membrane

Active transport ______. A)can involve the transport of ions B) requires the cell to expend energy C) can move molecules against their concentration gradient D) can use ATP as an energy source E) all of the above

E) All of the above

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Hypotonic

Having a lower concentration of solute than another solution

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

have hydrophobic tails that face the center of the membrane and are shielded from water.

Membrane phospholipids

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Which of the following statements regarding the movement of electrons during cellular respiration is true? Electrons tend to move away from O2. O2 is eventually oxidized by the electrons to form water. The electrons release large amounts of energy each time they are transferred from one molecule to another. O2 is reduced when it accepts electrons and forms water.

O2 is reduced when it accepts electrons and forms water.

Fermentation

Process by which cells release energy in the absence of oxygen

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

heat energy

a form of energy that is transferred by a difference in temperature

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

conversion of glucose to two three-carbon compounds

During cellular respiration, NADH is chemically converted into ATP. is reduced to form NAD+. delivers its electron load to the first electron carrier molecule. is the final electron acceptor.

delivers its electron load to the first electron carrier molecule.

Cellular respiration demonstrates the theme of matter and energy in that matter in food is turned into energy in ATP. energy in food is transferred to energy in ATP. matter in ATP is used to fuel biosynthesis. energy in food becomes matter in forming new molecules.

energy in food is transferred to energy in ATP.

Light energy with wavelengths that appear ______ is least useful to photosynthesis. violet green red orange

green

noncompetitive inhibition

inhibitor binds elsewhere on the enzyme; alters active site so that the substrate cannot bind

During cellular respiration, energy in glucose becomes stored in molecules of ammonia. is used to manufacture glucose. is released all at once. is carried by electrons.

is carried by electrons.

jATP and NADPH A) power sugar synthesis during the Calvin cycle. B) are products of the Calvin cycle. C) provide energy to photosystem I and photosystem II. D) are used in the electron transport chain to pump H+ into the thylakoid space.

power sugar synthesis during the Calvin cycle.

A product of glycolysis is ______. O2 (oxygen gas) ethyl alcohol (a 2-carbon molecule) pyruvic acid (a 3-carbon molecule) lactic acid (a 3-carbon molecule) NAD+ (an empty electron carrier)

pyruvic acid (a 3-carbon molecule)

Which of the following is a function of the plasma membrane? A)digestion of organic materials inside the cell B) lipid synthesis C) regulation of the passage of material into and out of the cell D) control center of the cell E) protein synthesis

regulation of the passage of material into and out of the cell

competitive inhibition

substance that resembles the normal substrate competes with the substrate for the active site

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

anaerobic cellular respiration

the process by which cells obtain energy from an energy source without using oxygen

aerobic cellular respiration

the process by which cells use oxygen to obtain usable energy from an energy source

The energy yield from the breakdown of a single molecule of glucose does not depend upon whether the NADH produced in glycolysis passes its electrons across the mitochondrial membrane to NAD+ or FAD. the supply of oxygen. the supply of carbon dioxide. whether some of the energy of the H+ gradient is used for work other than ATP production.

the supply of carbon dioxide.

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Isotonic

when the concentration of two solutions is the same

Fermentation means ______. without O2 without CO2 without ATP with O2 without mitochondria

without O2