Nemcc Hurley Biology Test 2
In a reaction in which the rate of the reverse reaction is equal to the rate of the forward reaction, a state of is attained.
dynamic equilibrium
During chemiosmosis, are transferred from NADH and FADH2 to electron acceptor molecules, and the energy released is used to create a(n) gradient across the inner mitochondrial membrane.
electrons; proton
Nucleosomes are best described as:
eukaryotic DNA associated with histone proteins
The reaction ATP + H20 - ADP + P is classified as an:
exergonic reaction.
If a cell is in G2:
it has twice the amount of DNA present in a telophase nucleus
The chromosome makeup of an individual organism is called a:
karyotype
12 H20 + 12 NADP + 18 ADP + Pi 6 O2 + 12 NADPH + 18 ATP summarizes the reactions of photosynthesis.
light-dependent
The reactions of photosynthesis are divided into two categories:
light-dependent reactions and carbon fixation reactions.
Eukaryotic chromosomes consist of:
linear DNA molecules complexed with positively charged histone proteins
One gram of contains more than twice the amount of energy of a gram of glucose.
lipids
An electron absorbs a photon of light energy and becomes energized; the electron shifts from a atomic orbital to a atomic orbital.
lower energy: higher energy
Enzymes are important biological catalysts because they:
lower the activation energy of a biochemical reaction.
The thylakoid membrane encloses a space called the:
lumen.
Integral proteins are:
made by ribosomes located on the rough endoplasmic reticulum.
The chlorophyll molecule has a porphyrin ring that contains a single atom of:
magnesium.
A key discovery that weakened the Davson-Danielli "sandwich" model of cell membranes was that:
membrane proteins were not uniform and did not form flattened sheets.
In Ca plants, reactions that fix CO2 into four-carbon compounds occur in:
mesophyll cells.
Chromosomes are condensed to their greatest extent during __________ of mitosis.
metaphase
The mitotic spindle is made of:
microtubules
The M phase of the cell cycle involves two main processes:
mitosis and cytokinesis
The __________ is responsible for the separation of the chromosomes during __________ of mitosis.
mitotic spindle; anaphase
Select the hydrogen acceptor molecule that stores electrons in the process of photosynthesis:
nicotinamide adenine dinucleotide phosphate (NADP")
Receptor-mediated endocytosis:
occurs when specific molecules combine with receptor proteins in the plasma membrane.
XH2 + NAD* -X+ NADH + H. In the preceding equation, NAD* is said to be in a state and NADH is in a state.
oxidized; reduced
Select the molecule that contains the least stored chemical energy :
oxygen
In aerobic respiration, the electrons associated with the hydrogen atoms in glucose are ultimately transferred to:
oxygen in a series of steps.
Plants, algae, and certain prokaryotes are:
photoautotrophs.
Light behaves not only as waves, but also as particles called:
photons.
The process by which light energy is converted into the stored chemical energy of organic molecules is:
photosynthesis.
By definition, substances that absorb visible light are called:
pigments.
Which of the following molecules is least likely to cross a cellular membrane by simple diffusion?
potassium ion
Which of the following represents the overall sequence of events during mitosis?
prophase, metaphase, anaphase, telophase
In glycolysis, a six-carbon glucose molecule is converted to two three-carbon molecules of:
pyruvate.
During aerobic respiration, oxygen is:
reduced.
Nucleosomes are organized into large coiled loops held together by:
scaffolding proteins
In the cotransport of glucose and sodium ions:
sodium ions are transported down their concentration gradient.
Hydrolases are one important class of enzyme that function to catalyze:
splitting a molecule using water.
An exergonic reaction is considered to be:
spontaneous.
Competitive inhibitors inhibit enzymatic reactions by:
temporarily bonding into the active site.
A cell is in metaphase if:
the chromosomes are aligned at the midplane of the cell
A glucose molecule that is metabolized via aerobic respiration has been completely broken down and released as CO, by the end of:
the citric acid cycle.
All of the following events occur during prometaphase EXCEPT:
the duplicated chromosomes become visible with the light microscope.
The role of the oxygen molecules required for aerobic respiration is:
to accept the low energy electrons at the end of the electron transport chain.
Once nerve cells become mature, they don't usually undergo cell division. Based on your knowledge of the cell cycle, you would predict that mature nerve cells become arrested in the __________ of the cell cycle.
G0 phase
Which of the following accurately represents the relationship between the terms anabolism, catabolism, and metabolism?
Metabolism = catabolism+ anabolism
Which of the following is not one of the intermediates or products of the carbon fixation reactions?
NADPH
Saturated fatty acids store more energy than unsaturated fatty acids. Based on your knowledge of aerobic respiration, you draw this conclusion because saturated fatty acids:
O are more highly reduced.
Organismal body heat is a:
O byproduct of exergonic reactions.
During the reactions of photosynthesis, is reduced and is oxidized.
O cO2: H20
Anaerobic respiration differs from aerobic respiration in that anaerobic respiration:
O can utilize NO, as the terminal electron acceptor.
Figure 7-2 Use the figure to answer the corresponding question(s).
O change in free energy.
contain and which receive energy from Reaction center complexes of the light-dependent reactions
O chlorophyll; proteins; antenna complexes
The action spectrum of photosynthesis best matches the absorption spectrum of:
O chlorophylls a and b.
The reactants of the Calvin cycle are:
O co2, ATP, and NADPH.
Which refers to an organic, nonpolypeptide compound that binds to the apoenzyme and serves as a cofactor?
O coenzyme
Chromosomes are duplicated during __________ of the cell cycle.
S phase
__________ contain identical DNA sequences and are held together by __________ during mitosis.
Sister chromatids; centromeres
Consider a U-tube that initially contains pure water on one side of a selectively permeable membrane and water plus solute on the other side. Which of the following best describes what will happen next?
Some water molecules become "bound up" with solute molecules and do not diffuse freely.
In a chloroplast, there is an outer and an inner membrane. The inner membrane encloses a fluid filled region called the:
Stroma
Engelmann concluded that chlorophyll in the chloroplasts is responsible for photosynthesis based on the following results:
The action spectrum of photosynthesis matched the maximum production of oxygen by Spirogyra, observed by the greatest accumulation of bacteria in the blue and red regions of the spectrum,
Which of the following statements is true of spontaneous reactions?
The amount of free energy after the reaction is less than before the reaction.
In cells that are constantly involved in secretion, an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane: if this does not occur, then what would happen?
The cell surface will keep expanding.
Which of the following statements concerning decarboxylation reactions is FALSE?
They involve the removal of two protons and two electrons.
Which of the following statements concerning anabolic reactions is FALSE?
They may split complex molecules into their components.
In the experiment in which Frye and Edidin fused the plasma membranes of a mouse and a human cell, what happened to the membrane proteins?
They moved laterally across the cell surface.
What is the function of nucleosomes?
To prevent DNA strands from tangling
Kilojoules are
Units of work
Which of the following statements is contrary to the first law of thermodynamics?
When gasoline is burned, its energy is destroyed.
Chorophyll
absorbs red and blue light, and reflects green light.
Catabolic reactions involve the:
breakdown of large organic molecules to simple building blocks.
Figure 5-1 Use the figure to answer the corresponding question(s)
. O There has been no net water movement.
In aerobic respiration, glucose is completely:
. oxidized to carbon dioxide.
How many electrons are needed to reduce one molecule of NADP* to NADPH?
2
Figure 9-3 Use the figure to answer the corresponding question(s).
3
When one molecule of glucose is completely oxidized in aerobic respiration, the net amount of ATP produced is:
36 to 38.
In the skeletal muscle cells of vertebrates, as many as molecules of ATP are produced from one molecule of glucose. This is less than might be expected, because electrons from NADH produced during glycolysis must be shuttled through the membrane at a cost.
36; mitochondrial
Figure 9-3 Use the figure to answer the corresponding question(s)
4
During the citric acid cycle, each acetyl group entering the cycle yields:
4 CO2 +6 NADH +2 FADH2 +2 ATP
Vegetable oil is different from animal fat in that the phospholipids in vegetable oil have fatty acid tails that:
Bend at each double bond
Which of the following are accessory photosynthetic pigments that expand the spectrum of light that provides energy for photosynthesis:
Both caroteniods and chorophyll b.
Select the processes that are matched with the incorrect amount of ATP produced by that process per glucose molecule.
Citric acid cycle-4 ATP
In eukaryotes, glycolysis occurs in the:
Cytosol
Which of the following describes how facilitated diffusion is powered?
Energy is required to do the work of establishing and maintaining a concentration gradient.
Noncyclic electron transport needs a constant supply of electrons. These are obtained from:
H20.
Oxygen produced by photosynthesis comes directly from:
H20.
What refers to the situation in which the binding of a substrate to the enzyme causes a change in the enzyme's shape, facilitating an enzyme's function?
Induced fit
The cell cycle of a typical somatic cell consists of __________ and M phase.
Interphase
What is meant by the term "fluid mosaic model"?
It is the movement of proteins within the phospholipid bilayer.
Which of the following statements about the sodium- potassium pump is true?
It transports 3 sodium ions out of the cell in exchange for 2 potassium ions into the cell.
The kinetochore serves which of the following functions?
Kinetochores attach to microtubules during mitosis
Select the molecule that contains the most stored chemical energy:
Lactate
Select the receptor mediated endocytosis events that are in the correct (before,
Ligand binds to receptors; coated vesicle forms by endocytosis.
Glycolysis yields a net energy profit of ATP molecules per molecule of glucose.
O 2
Figure 9-1 Use the figure to answer the corresponding question(s).
O 3 and 4.
The overall reactions of photosynthesis are best summarized as:
O 6 CO2 + 12 H20- CH1206 + 6 O2+6 H20.
Figure 7-1 Use the figure to answer the corresponding question(s).
O AG is positive.
Select the compound that contains the most energy:
O ATP
Thylakoid membranes are involved in synthesis.
O ATP
Which of the following is an glycolysis?
O ATP
In the electron transport chain, exergonic redox processes drive the endergonic reaction in which:
O ATP is produced by phosphorylation of ADP.
In chemiosmosis, ATP is produced as hydrogen ions (protons) pass through:
O ATP synthase.
Carrier proteins are involved in:
O Both facilitated diffusion and active transport
The overall reaction for the aerobic respiration of glucose is summarized as:
O CH120, 6 O2 +6 H;0 - 6 CO2 + 12 H20 + Energy.
Which of the following statements concerning activation energy is FALSE?
O Catalysts raise a reaction's activation energy.
The reactants of the light-dependent reactions are
O H;0, ADP, and NADP+
Which of the following statements concerning ATP is FALSE?
O It stores energy for long periods.
Which of the following statements concerning enzymes is FALSE?
O Most enzymes are RNA molecules.
Select the reduced molecule:
O NADH
is process where energy (as electrons) is released. whereas is a process where energy (as electrons) is accepted.
O Oxidation; reduction
Which of the following statements is not correct about lactic acid fermentation?
O Oxygen is the final electron acceptor of this pathway.
The first step in the Calvin cycle is the attachment of carbon dioxide to:
O RUBP (ribulose bisphosphate).
Who proposed the fluid mosaic model of cell membrane structure in 1972?
O Singer and Nicholson
Which of the following statements about lipid bilayers is FALSE?.
O They are inflexible
Which of the following is not a characteristic of aguaporins?
O They cause dehydration
Which of the following statements concerning phospholipids is FALSE?
O They contain three fatty acids chains.
A group of thylakoid discs make up:
O a granum.
Aerobic respiration is classified as:
O a redox process.
In the overall reactions of photosynthesis, it appears that hydrogen atoms are transferred from water to carbon dioxide to form a carbohydrate. This type of reaction is classified as:
O a redox reaction.
The electrons lost by the P680 reactive center are replaced from:
O a water molecule.
Figure 9-2 Use the figure to answer the corresponding question(s).
O absorption spectra for chlorophylls a and b.
Even though a bacterium contains a higher concentration of sodium ions than in the surrounding pond water, the sodium ions continue to enter the bacterium. Evidently, sodium ions are entering the cell by:
O active transport.
Peter Mitchell demonstrated ATP production by aerobic bacteria by placing the bacteria in:
O an acidic environment.
When the free energy of the reactants is greater than the free energy of the products, such a reaction is referred to as:
O an exergonic reaction.
An organism can exchange matter and energy with its surroundings. Thus, any change in an organism's energy content must be balanced bya corresponding change in the energy content of the surroundings. As such, an organism is referred to as:
O an open system.
Integral proteins:
O are amphipathic.
Consider the following two chemical equations: A. glucose + fructose sucrose + H2O, AG +27KJ/mole (or +6,5 kcal/mole) B. glucose + fructose + ATP - sucrose + ADP + P, AG= -5kJ/mole (or -1.2 kcal/mole)
O combining endergonic and an exergonic reaction.
A transmembrane protein differs from other membrane proteins because it:
O completely extends through the membrane.
In order for a cell to maintain a high degree of order, it must:
O constantly use energy.
The passive movement of a substance along its concentration gradient is termed:
O diffusion.
The transfer of electrons from one compound to another is equivalent to transfer,
O energy
Every type of chemical bond contains a certain amount of energy. The total bond energy, which is essentially equivalent to the total potential energy of the system, is a quantity known as:
O enthalpy.
Which word is defined by this statement: A measure of this- disorder, or randomness?
O entropy
Figure 5-2 Use the figure to answer the corresponding question(s).
O exocytosis.
Plasmodesmata of plant cells are functionally equivalent to of animal cells.
O gap junctions
Figure 9-1 Use the figure to answer the corresponding question(s).
O gas exchange.
Select the phosphorylation reaction:
O glucose + ATP - glucose-P + ADP
Solutions that are isotonic:
O have equal concentrations of solute and water.
Figure 5-2 Use the figure to answer the corresponding question(s).
O hormones.
ATP is formed when the thylakoid lumen.
O hydrogen ions leave
FAD and cytochromes are classified as:
O hydrogen or electron acceptors.
Which of the following is not one of the four stages of the aerobic respiration of glucose?
O hydrolysis
Penicillin is a drug that acts by:
O irreversibly inhibiting transpeptidase.
Select the entyme that does not match the action
O kinase-breaks peptide bonds
The higher the concentration of solute in a solution, the the effective water concentration and the the osmotic pressure.
O lower; higher
The sum of all chemical activities taking place in an organism is:
O metabolism.
If conditions are aerobic, pyruvate flows directly into where some of its atoms are converted next to
O mitochondia; acetyl coenzyme A
Which of the following membrane activities does NOT require the expenditure of energy by the cell?
O osmosis
A human white blood cell engulfs a bacterial cell by:
O phagocytosis.
The synthesis of ATP during photosynthesis or respiration Occurs as a result of:
O phosphorylation of ADP.
The of a chlorophyll molecule is(are) responsible for absorbing light.
O porphyrin ring
Energy stored within the molecules of ATP is in the form of - energy.
O potential
Figure 9-2 Use the figure to answer the corresponding question(s).
O red and blue wavelengths.
Aerobic respiration, anaerobic respiration, and fermentation:
O release free energy.
Facilitated diffusion:
O requires a specific transport protein.
A bottle of perfume is opened on the opponite side of the room and within minutes you beggin to smell the perfume. This phenomenon is a classic eample of
O simple diffusion.
Simple diffusion may involve the movement of through the plasma membrane down a concentration gradient.
O small nonpolar molecules
Biological membranes are normally permeable to:
O small, hydrophobic molecules.
The substance on which an enzyme acts is called the:
O substrate
Which of the following is not associated with the thylakoid membranes?
O the Calvin cycle
The transfer of electrons from glucose to oxygen during aerobic respiration takes place in a stepwise fashion through a number of intermediates rather than by direct transfer. This is because:
O the energy of the electrons can be used to make ATP.
The life and death of cells are governed by:
O the laws of thermodynamics.
In photosynthesis, ATP and NADPH are produced during
O the light-dependent phase.
The reactions that occur in the thylakoid membranes are:
O the light-dependent reactions.
The ultimate source of energy for almost all living organisms is:
O the sun.
A plant cell placed in a hypertonic solution will:
O undergo plasmolysis.
Deamination of amino acids in mammals yields amino groups that are converted to which is(are) excreted, and which is(are) converted to one of the reactants of glycolysis or the citric acid cycle.
O urea; carbon chains
Most components of energy conversion systems evolved very early; thus, the most fundamental aspects of energy metabolism tend to be:
O very similar in a wide range of different organisms.
During the light-dependent reactions of photosynthesis, a constant supply of electrons is provided by:
O water.
A wilted flower placed in a vase of water for several hours became stiff and stood erect. When a fresh flower was placed in a salt solution, it wilted. From this information we can say that :
The fresh water is hypertonic and the salt solution is hypertonic to the cells of the flower
A drowning death would be most directly due to:
The lack of oxygen to accept hydrogen,
Which of the following statements about the electron transport chain is true?
The proton gradient established during electron transport is a form of potential energy.
Figure 7-1 Use the figure to answer the corresponding question(s).
The reaction is endergonic, and also the products have more free energy than the reactants.
You conduct an experiment in which you add increasing amounts of substrate to an enzyme solution and then measure the resulting reaction rate. You graph your results, plotting the rate of the reaction on the Y-axis versus substrate concentration on the X-axis. What do you conclude from your graph?
The reaction rate increases with increasing substrate concentration up to a point, above which the rate remains constant.
Figure 5-1 Use the figure to answer the corresponding question(s).
These red blood cells have shrunken in response to a hypertonic external solution.
If phospholipids form a spherical structure when placed in water, then which of the following is the most logical conclusion about those phosopholipid molecules?
They are cone-shaped.
The ability of some bacteria to produce lactate is exploited by humans to make:
Yogurt and sauerkraut
A bacterial chromosome consists of:
a circular DNA molecule many times larger than the cell
Penicillin is toxic to certain dividing bacterial cells because it prevents cell wall formation, causing the cells to burst. This indicates that the bacteria live in:
a hypotonic medium.
Cytokinesis in animal cells involves contraction of a ring of __________ microfilaments.
actin plus myosin
Parts of the enzyme molecule that interact with a substrate are called:
active sites.
The structures in this figure: mc055-1.jpg
allow the transport of small molecules and ions between adjacent cells.
An allosteric enzyme:
allows a substance other than the substrate to bind to the enzyme, thereby activating or inactivating it.
Pathways that have an overall energy requirement are referred to as:
anabolic reactions.
Duplicated centrioles move to opposite poles of a dividing __________ cell during __________ of the cell cycle.
animal; prophase
During fermentation, the immediate fate of the electrons in NADH is that they:
are transferred to an organic molecule.
All of the following are functions of the cell membrane EXCEPT:
being freely permeable to all substances
Chlorophyll absorbs primarily and regions of the visible spectrum.
blue; red
Peripheral proteins are linked to either surface of the plasma membrane by:
bonding to integral proteins through noncovalent interactions.
Cellular respiration is most accurately described as aln) process.
catabolic
The splitting of molecules into smaller components is referred to as:
catabolism.
Because enzymes affect the speed of chemical reactions without being consumed, they are referred to as:
catalysts.
Which of the following is common to both photosynthesis and aerobic respiration?
chemiosmosis
When hydrogen ions (protons) are pumped across the inner mitochondrial membrane, they form a proton gradient. ATP is then formed by a process known as:
chemiosmosis.
Animals, fungi, and many bacteria that use organic molecules as a source of both energy and carbon are:
chemoheterotrophs.
The most important pigment(s) for the process of photosynthesis isfare):
chlorophyll a.
During prophase, __________ is(are) compacted into visible chromosomes.
chromatin
One product of the initial (first) reaction of the citric acid cycle is:
citrate.
Select the anaerobic pathway.
fermentation
The production of alcohol or lactate from pyruvate during occurs as a means of regenerating from
fermentation: NAD: NADH
Cholesterol within membranes functions as a(n). through its interactions with both hydrophobic and hydrophilic parts of phospholipids.
fluidity buffer
Electrons that are excited to a higher energy level may be transferred to an electron acceptor or may return to a ground state. If the latter occurs, energy can be released as an emission of light in a process known as:
fluorescence.
Considering only glycolysis and the conversion of pyruvate molecules to acetyl CoA molecules, how many NADH molecules will be produced from one glucose molecule?
four
What is the correct sequence of wavelengths (beginning with the shortest)?
gamma rays, x-rays, UV, visible light, infrared, microwaves, TV and radio waves
Studies of glucose transport in liposomes have revealed that:
glucose binds to the carrier protein causing the carrier protein to change its shape during the transport process.
Which of the following molecules can provide energy through cellular respiration?
glucose. lipids and proteins
Which process does not match the location in a typical eukaryotic cell?
glycolysis-mitochondrion
A patient who has had a severe hemorrhage accidentally major blood vessel. You would expect this mistake to: receives a large transfusion of distilled water directly into a
have serious, perhaps fatal consequences because the red blood cells could swell and burst.
Which of the following does not represent a method by which cells repulate entyme activity?
heat denaturation of the enyme
In a lipid bilayer, fatty acid tails face each other within the bilayer and form a region that excludes water.
hydrophobic
If the concentration of solutes in a cell is less than the concentration of solutes in the surrounding fluid, then the extracellular fluid is said to be:
hypertonic.
If one continues to increase the temperature in an enzyme- catalyzed reaction, the rate of the reaction:
increases and then decreases rapidly.
One important regulation point in the aerobic respiration of mammals occurs in glycolysis at the site of the enzyme phosphofructokinase, which is:
inhibited by high levels of ATP.
Pinocytosis:
is the nonspecific uptake of fluids by pinching inward of the plasma membrane,
The maintenance of a high ATP to ADP ratio within cells ensures that:
the hydrolysis of ATP to ADP will be strongly exergonic.
Although glucose molecules constantly diffuse into a cell along their concentration gradient, equilibrium is never reached and glucose continues to enter the cell. This is a direct result of:
the rapid and continuous formation of glucose phosphates within the cell.
The electron transport chain of photosynthesis is located in the:
thylakoid membrane.
Chlorophyll and accessory photosynthetic pigments are associated with the:
thylakoid membranes.
Coenzyme Q
transfers electrons.
An ABC transporter:
uses the energy of ATP to transport solutes.