Biology 111

Questão 1 de 94

1

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Selecione uma das seguintes:

ATP is transported into the cell from the circulatory system.
Other cells take over, and the muscle cells that have used up their ATP cease to function.
Catabolic processes are activated that generate more ATP.
He or she has to sit down and rest.

Explicação

Questão 2 de 94

1

A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases, although they do not often hydrolize ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If resting muscle cell's cytosol has a free calcium ion concentration of 10^(-7) while the concentration in the SR is 10^(-2), then how is the ATPase acting?

Selecione uma das seguintes:

ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient.
ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient.
ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR.
ATPase activity must be transferring Ⓟi to the SR to enable this to occur.

Explicação

Questão 3 de 94

1

Cell membranes are asymmetrical. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

Selecione uma das seguintes:

The two sides of a cell membrane face different environments and carry out different functions.
Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical.
Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical.
Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature.

Explicação

Questão 4 de 94

1

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups of acetyl CoA molecules. These acetyl groups ________.

Selecione uma das seguintes:

directly enter the energy-yielding stages of glycolysis.
directly enter the electron transport chain.
are directly decarboxylated by pyruvate dehydrogenase.
directly enter the citric acid cycle.

Explicação

Questão 5 de 94

1

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ______.

Selecione uma das seguintes:

3'UAACGU5'
5'UGCAAU3'
5'TAACGT3'
5'TGCAAT3'

Explicação

Questão 6 de 94

1

In solution, why do hydrolysis reactions occur more readily than condensation reactions?

Selecione uma das seguintes:

Hydrolysis raises G, or Gibbs free energy.
Hydrolysis increases entropy and is endergonic.
Hydrolysis increases entropy and is exergonic.
Hydrolysis decreases entropy and is exergonic.

Explicação

Questão 7 de 94

1

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Selecione uma das seguintes:

As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth.
Living organisms are able to transform energy into entropy.
Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe.
Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time.

Explicação

Questão 8 de 94

1

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this probably mean?

Selecione uma das seguintes:

Proton pumps are necessary to all cell membranes.
Cells of each domain evolved proton pumps independently when oceans became more acidic.
Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.

Explicação

Questão 9 de 94

1

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.

Selecione uma das seguintes:

increasing the percentage of cholesterol molecules in the membranes
decreasing the number of hydrophobic proteins in the membrane
cotransport of glucose and hydrogen
increasing the percentage of unsaturated phospholipids in the membrane

Explicação

Questão 10 de 94

1

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ______.

Selecione uma das seguintes:

allosteric regulation
active transport
a reaction with a positive delta G
an endergonic reaction coupled to an exergonic reaction

Explicação

Questão 11 de 94

1

Which of the following processes includes all others?

Selecione uma das seguintes:

passive transport
osmosis
facilitated diffusion
transport of an ion down its electrochemical gradient

Explicação

Questão 12 de 94

1

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Selecione uma das seguintes:

It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.
It is found in prokaryotic cells but not in eukaryotic cells.
It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.
It produces much less ATP than does oxidative phosphorylation.

Explicação

Questão 13 de 94

1

A localized group of organisms that belong to the same species is called a

Selecione uma das seguintes:

biosystem
community
population
ecosystem
family

Explicação

Questão 14 de 94

1

Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into

Selecione uma das seguintes:

the energy of motion
carbon dioxide and water
the potential energy of chemical bonds
oxygen
kinetic energy

Explicação

Questão 15 de 94

1

The main source of energy for producers in an ecosystem is

Selecione uma das seguintes:

light energy
kinetic energy
thermal energy
chemical energy
ATP

Explicação

Questão 16 de 94

1

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

Selecione uma das seguintes:

animal
plant
archaea
fungi
protists

Explicação

Questão 17 de 94

1

To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology?

Selecione uma das seguintes:

evolution
emergent properties
reductionism
the cell theory
feedback regulation

Explicação

Questão 18 de 94

1

Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of which type of regulation?

Selecione uma das seguintes:

a bioinformatic system
positive feedback
negative feedback
feedback inhibition
enzymatic catalysis

Explicação

Questão 19 de 94

1

When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of

Selecione uma das seguintes:

catalytic feedback
positive feedback
negative feedback
bioinformatic regulation
protein-protein interactions

Explicação

Questão 20 de 94

1

The elongation of the leading strand during DNA replication

Selecione uma das seguintes:

Proceeds away from the replication fork
Depends upon the action of DNA polymerase
Proceeds in the 3' to 5' direction
Does not require a template strand

Explicação

Questão 21 de 94

1

What does the reactivity of an atom depend on?

Selecione uma das seguintes:

Number of valence shells in the atom.
Number of orbitals found in the atom.
Number of electrons in each orbital in the atom.
Presence of unpaired electrons in the outer valance shell of the atom.
Presence of the hybridized orbitals in the atom.

Explicação

Questão 22 de 94

1

A covalent chemical bond is one in which...

Selecione uma das seguintes:

electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.
protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms.
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shell of both atoms.
outer-shell electrons of an atom are transferred to the inner electron shells of another atom.
the inner-shell electrons of one atom are transferred to the outer-shell of another atom.

Explicação

Questão 23 de 94

1

Which of the following is the best example of gene expression?

Selecione uma das seguintes:

A frog adapts to variation in its environmental temperature.
Mouse fur color results from pigment formed by gene-encoded enzymes.
DNA is replicated during the S phase of the cell cycle.

Explicação

Questão 24 de 94

1

What results from an unequal sharing of electrons between atoms?

Selecione uma das seguintes:

A nonpolar covalent bond.
A polar covalent bond.
An ionic bond.
A hydrogen bond.
A hydrophobic interaction.

Explicação

Questão 25 de 94

1

Which bonds must be broken for water to vaporize?

Selecione uma das seguintes:

Ionic bonds
Nonpolar covalent bonds
Polar covalent bonds
Hydrogen bonds
Covalent bonds

Explicação

Questão 26 de 94

1

One liter of a solution of pH has how many more hydrogen ions (H+) than 1L of a solution of pH 6?

Selecione uma das seguintes:

4 times more
400 times more
4,000 times more
10,000 times more
100,000 times more

Explicação

Questão 27 de 94

1

Observe the structure of glucose and fructose in the figure. These two molecules are...

Selecione uma das seguintes:

geometric isomers
enantiomers
structural isomers
nonisotopic isomers

Explicação

Questão 28 de 94

1

Polymers of polysaccharides, fats and proteins are all synthesized from monomers by which process?

Selecione uma das seguintes:

Connecting monosaccharides together (condensation reactions)
The addition of water to each monomer (hydrolysis)
The removal of water (dehydration reactions)
Ionic bonding of the monomers
The formation of disulfide between monomers

Explicação

Questão 29 de 94

1

The 20 different amino acids found in polypeptides exhibit different chemical and physical properties because of different

Selecione uma das seguintes:

Carboxyl groups attached to an alpha (α) carbon
Amino groups attached to an alpha (α) carbon
Side chains (R groups)
Alpha (α) carbons
Asymmetric carbons

Explicação

Questão 30 de 94

1

The tertiary structure of a protein is the...

Selecione uma das seguintes:

bonding together of several polypeptide chains by weak bonds.
order in which amino acids are joined in a polypeptide chain.
unique three-dimensional shape of the fully folded polypeptide.
organization of a polypeptide chain into a a-helix or B-pleated sheet.

Explicação

Questão 31 de 94

1

Which of the following best describes the flow of information in eukaryotic cells?

Selecione uma das seguintes:

DNA → RNA → Proteins
RNA → Proteins → DNA
Proteins → DNA → RNA
RNA → DNA → Proteins
DNA → Proteins → RNA

Explicação

Questão 32 de 94

1

Which of the following are nitrogenous bases found in DNA?

Selecione uma ou mais das seguintes:

thymine
adenine
uracil
guanine
cytosine

Explicação

Questão 33 de 94

1

Which of the following types of molecules are the major structural components of the cell's membrane?

Selecione uma ou mais das seguintes:

Phospholipids
Cellulose
Nucleic Acids
Proteins
Cholesterol
Glycoproteins

Explicação

Questão 34 de 94

1

The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is...

Selecione uma ou mais das seguintes:

Diffusion
Active transport
Osmosis
Facilitated diffusion
Exocytosis

Explicação

Questão 35 de 94

1

The sodium-potassium is called an electrogenic pump because it...

Selecione uma das seguintes:

Pumps equal quantities of Na+ and K+ across the membrane.
Pumps hydrogen ions out of cells.
Contributes to the membrane potential.
Ionizes sodium and potassium atoms.
Is used to drive the transport of other molecules against a concentration gradient.

Explicação

Questão 36 de 94

1

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

Selecione uma das seguintes:

Catalysis
Metabolism
Anabolism
Dehydration
Catabolism

Explicação

Questão 37 de 94

1

Which of the following statements regarding ATP is (are) correct?

Selecione uma ou mais das seguintes:

ATP serves as a main energy shuttle inside cells.
ATP drives endergonic reactions in the cell by the enzymatic transfer of the phosphate group to specific reactants.
The regeneration of ATP from ADP and phosphate is an endergonic reaction.

Explicação

Questão 38 de 94

1

In addition to ATP, what are the end products of glycolysis?

Selecione uma das seguintes:

CO2 and H2O
CO2 and pyruvate
NADH and pyruvate
CO2 and NADH
H2O, FADH2, and citrate

Explicação

Questão 39 de 94

1

The primary role of oxygen in cellular respiration is to...

Selecione uma das seguintes:

Yield energy in the form of ATP as it is passed down the respiratory chain.
Act as an acceptor for the electrons and hydrogen.
Combine with carbon, forming CO2.
Combine with lactate, forming pyruvate.
Catalyze the reactions of glycolysis.

Explicação

Questão 40 de 94

1

From the perspective of the cell receiving the message, the three stages of cell signaling are...

Selecione uma das seguintes:

The paracrine, local, and synaptic stages
Signal reception, signal transduction, and cellular response
Signal reception, nucleus disintegration, and new cell generation
The alpha, beta, and gamma stages
Signal reception, cellular response, and cell division

Explicação

Questão 41 de 94

1

Which of the following is/are true of ligand-gated ion channels?

Selecione uma ou mais das seguintes:

They are important in the nervous system.
They lead to changes in sodium and calcium concentration in cells.
They open or close in response to a chemical signal.

Explicação

Questão 42 de 94

1

Which of the following is true of the process of meiosis?

Selecione uma das seguintes:

Two diploid cells result
Four diploid cells result
Four haploid cells result
Four autosomes result
Four chiasmata result

Explicação

Questão 43 de 94

1

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

Selecione uma das seguintes:

There is considerable genetic variation in garden peas.
Traits are inherited in discrete units, and are not the results of "blending".
Recessive genes occur more frequently in the F1 than do dominant ones.
Genes are composed of DNA.
An organism that is homozygous for many recessive traits is at a disadvantage.

Explicação

Questão 44 de 94

1

The leading and the lagging strands differ in that

Selecione uma das seguintes:

The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction
The leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end.
The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short fragments that are ultimately stitched together.

Explicação

Questão 45 de 94

1

RNA polymerase and DNA polymerase differ in that

Selecione uma das seguintes:

RNA polymerase uses RNA as a template and DNA polymerase uses a DNA template
RNA polymerase binds to single-stranded DNA and DNA polymerase binds to double-stranded DNA
RNA polymerase is much more accurate than DNA polymerase
RNA polymerase can initiate RNA synthesis but DNA polymerase requires a primer to initiate DNA synthesis.
RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA.

Explicação

Questão 46 de 94

1

A frameshift mutation could result from...

Selecione uma das seguintes:

a base insertion only
a base deletion only
a base substitution only
deletion of three consecutive bases
either an insertion or a deletion of a base

Explicação

Questão 47 de 94

1

Thylakoids are present in chloroplasts.

Selecione uma das opções:

VERDADEIRO
FALSO

Explicação

Questão 48 de 94

1

The presence of cholesterol in the plasma membranes of some animals

Selecione uma das seguintes:

enables the membrane to stay fluid more easily when cell temperature drops.
enables the animal to remove hydrogen atoms from saturated phospholipids.
enables the animal to add hydrogen atoms to unsaturated phospholipids.
makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
makes the animal more susceptible to circulatory disorders.

Explicação

Questão 49 de 94

1

According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

Selecione uma das seguintes:

They can move laterally along the plane of the membrane.
They frequently flip-flop from one side of the membrane to the other.
They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.
They are free to depart from the membrane and dissolve in the surrounding solution.
They have hydrophilic tails in the interior of the membrane.

Explicação

Questão 50 de 94

1

What kinds of molecules pass through a cell membrane most easily?

Selecione uma das seguintes:

large and hydrophobic
small and hydrophobic
large polar
ionic
monosaccharides such as glucose

Explicação

Questão 51 de 94

1

Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?

Selecione uma das seguintes:

CO2
an amino acid
glucose
K+
starch

Explicação

Questão 52 de 94

1

Molecules with which functional groups may form polymers via dehydration reactions?

Selecione uma ou mais das seguintes:

hydroxyl groups
carbonyl groups
carboxyl groups

Explicação

Questão 53 de 94

1

Which of these molecules is not formed by dehydration reactions?

Selecione uma das seguintes:

Fatty acids
Disaccharides
DNA
Protein
Amylose

Explicação

Questão 54 de 94

1

Which of these classes of biological molecules consist of both small molecules and macromolecular polymers?

Selecione uma das seguintes:

lipids
carbohydrates
proteins
nucleic acids

Explicação

Questão 55 de 94

1

Which of the following is not a polymer?

Selecione uma das seguintes:

glucose
starch
cellulose
chitin
DNA

Explicação

Questão 56 de 94

1

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

Selecione uma das seguintes:

12
11
10
9
8

Explicação

Questão 57 de 94

1

Which of the following are polysaccharides?

Selecione uma ou mais das seguintes:

lactose
glycogen
chitin
cellulose
amylopectin

Explicação

Questão 58 de 94

1

The bonding of two amino acid molecules to form a larger molecule requires which of the following?

Selecione uma das seguintes:

Removal of a water molecule
Addition of a water molecule
Formation of a glycosidic bond
Formation of a hydrogen bond
Both removal of a water molecule and formation of a hydrogen bond

Explicação

Questão 59 de 94

1

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?

Selecione uma das seguintes:

101
100
99
98
97

Explicação

Questão 60 de 94

1

What methods may be used to elucidate the structures of purified proteins?

Selecione uma ou mais das seguintes:

X-ray crystallography
bioinformatics
analysis of amino acid sequence of small fragments
NMR spectroscopy

Explicação

Questão 61 de 94

1

One of the primary functions of RNA molecules is to

Selecione uma das seguintes:

transmit genetic information to offspring.
function in the synthesis of proteins.
make a copy of itself, thus ensuring genetic continuity.
act as a pattern or blueprint to form DNA.
form the genes of higher organisms.

Explicação

Questão 62 de 94

1

The element present in all organic molecules is

Selecione uma das seguintes:

Hydrogen
Oxygen
Carbon
Nitrogen
Phosphorus

Explicação

Questão 63 de 94

1

Differences among organisms are caused by...

Selecione uma das seguintes:

large differences in elemental composition from organism to organism.
differences in the types and relative amounts of organic molecules synthesized by each organism.
differences in the elements that bond with carbon in each organism.
differences in the sizes of the organic molecules in each organism.
differences in inorganic compounds present in each organism.

Explicação

Questão 64 de 94

1

A carbon atom is most likely to form what kind of bond(s) with other atoms?

Selecione uma das seguintes:

ionic
hydrogen
covalent
covalent bonds and hydrogen bonds
ionic bonds, covalent bonds, and hydrogen bonds

Explicação

Questão 65 de 94

1

Why are hydrocarbons insoluble in water?

Selecione uma das seguintes:

The majority of their bonds are polar covalent carbon-to-hydrogen linkages.
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
They are hydrophilic.
They exhibit considerable molecular complexity and diversity.
They are lighter than water.

Explicação

Questão 66 de 94

1

How many structural isomers are possible for a substance having the molecular formula C₄H₁₀?

Selecione uma das seguintes:

1
2
4
3
11

Explicação

Questão 67 de 94

1

Which of the following statements correctly describes cis-trans isomers?

Selecione uma das seguintes:

They have variations in arrangement around a double bond.
They have an asymmetric carbon that makes them mirror images.
They have the same chemical properties.
They have different molecular formulas.
Their atoms and bonds are arranged in different sequences.

Explicação

Questão 68 de 94

1

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that

Selecione uma das seguintes:

have identical chemical formulas but differ in the branching of their carbon skeletons.
are mirror images of one another.
exist in either linear chain or ring forms.
differ in the location of their double bonds.

Explicação

Questão 69 de 94

1

A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?

Selecione uma das seguintes:

It lacks an asymmetric carbon, and it is probably a fat or lipid.
It should dissolve in water.
It should dissolve in a nonpolar solvent.
It won't form hydrogen bonds with water.
It is hydrophobic.

Explicação

Questão 70 de 94

1

Which two functional groups are always found in amino acids?

Selecione uma ou mais das seguintes:

ketone
methyl
amino
carbonyl
carboxyl
hydroxyl
sulfhydryl

Explicação

Questão 71 de 94

1

Why are human sex hormones considered to be lipids?

Selecione uma das seguintes:

They are essential components of cell membranes.
They are not soluble in water.
They are made of fatty acids.
They are hydrophilic compounds.
They contribute to atherosclerosis.

Explicação

Questão 72 de 94

1

All of the following contain amino acids except...

Selecione uma das seguintes:

hemoglobin
cholesterol
abtibodies
enzymes
insulin

Explicação

Questão 73 de 94

1

Which of the following descriptions best fits the class of molecules known as nucleotides?

Selecione uma das seguintes:

A nitrogenous base and a phosphate group.
A nitrogenous base and a pentose sugar.
A nitrogenous base, a phosphate group, and a pentose sugar.
A phosphate group and an adenine or uracil.
A pentose sugar and a purine or pyrimidine.

Explicação

Questão 74 de 94

1

A primary objective of cell fractionation is to...

Selecione uma das seguintes:

view the structure of cell membranes.
sort cells based on their size and weight.
determine the size of various organelles.
separate the major organelles so that their particular functions can be determined.
separate lipid-soluble from water-soluble molecules.

Explicação

Questão 75 de 94

1

All of the following are part of a prokaryotic cell except...

Selecione uma das seguintes:

DNA
a cell wall
a plasma membrane
ribosomes
an endoplasmic reticulum

Explicação

Questão 76 de 94

1

Which of the following is a major cause of the size limits for certain types of cells?

Selecione uma das seguintes:

Limitation on the strength and integrity of the plasma membrane as cell size increases.
The difference in plasma membranes between prokaryotes and eukaryotes.
Evolutionary progression in cell size; more primitive cells have smaller sizes.
The need for a surface area of sufficient area to support the cell's metabolic needs.
Rigid cell walls that limit cell size expansion.

Explicação

Questão 77 de 94

1

Which organelle or structure is absent in plant cells?

Selecione uma das seguintes:

mitochondria
golgi vesicles
microtubules
centrosomes
peroxisomes

Explicação

Questão 78 de 94

1

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

Selecione uma das seguintes:

lipids
glycogen
proteins
cellulose
nucleic acids

Explicação

Questão 79 de 94

1

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition?

Selecione uma das seguintes:

the endoplasmic reticulum
the Golgi apparatus
the lysosome
mitochondria
membrane-bound ribosomes

Explicação

Questão 80 de 94

1

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

Selecione uma das seguintes:

lysosome
vacuole
mitochondrion
Golgi apparatus
peroxisome

Explicação

Questão 81 de 94

1

Which of the following is true for anabolic pathways?

Selecione uma das seguintes:

They do not depend on enzymes.
They are usually highly spontaneous chemical reactions.
They consume energy to build up polymers from monomers.
They release energy as they degrade polymers to monomers.

Explicação

Questão 82 de 94

1

Which of the following is the smallest closed system?

Selecione uma das seguintes:

a cell
an organism
an ecosystem
Earth
the universe

Explicação

Questão 83 de 94

1

Which of the following is true of metabolism in its entirety in all organisms?

Selecione uma das seguintes:

Metabolism depends on a constant supply of energy from food.
Metabolism depends on an organisms adequate hydration.
Metabolism uses all of an organism's resources.
Metabolism consists of all the energy transformation reactions in an organism.

Explicação

Questão 84 de 94

1

A chemical reaction that has a positive ΔG is correctly described as...

Selecione uma das seguintes:

endergonic
endothermic
exergonic
spontaneous

Explicação

Questão 85 de 94

1

Why is ATP an important molecule in metabolism?

Selecione uma das seguintes:

Its hydrolysis provides an input of free energy for exergonic reactions.
It provides energy coupling between exergonic and endergonic reactions.
Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy.
Its terminal phosphate bond has higher energy than the other two.
It is one of the four building blocks for DNA synthesis.

Explicação

Questão 86 de 94

1

Which of the following statements is true concerning catabolic pathways?

Selecione uma das seguintes:

They combine molecules into more energy-rich molecules.
They supply energy, primarily in the form of ATP, for the cell's work.
They are endergonic.
They are spontaneous and do not need enzyme catalysis.

Explicação

Questão 87 de 94

1

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

Selecione uma das seguintes:

It is used to power yet more cellular work.
It is used to store energy as more ATP.
It is used to generate ADP from nucleotide precursors.
It is lost to the environment.

Explicação

Questão 88 de 94

1

The active site of an enzyme is the region that

Selecione uma das seguintes:

binds allosteric regulators of the enzyme.
is involved in the catalytic reaction of the enzyme.
binds noncompetitive inhibitors of the enzyme.
is inhibited by the presence of a coenzyme or a cofactor.

Explicação

Questão 89 de 94

1

For the enzyme-catalyzed reaction shown in the figure, which of these treatments will cause the greatest increase in the rate of the reaction, if the initial reactant concentration is 1.0 micromolar?

Selecione uma das seguintes:

doubling the activation energy needed
cooling the reaction by 10°C
doubling the concentration of the reactants to 2.0 micromolar
doubling the enzyme concentration
increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

Explicação

Questão 90 de 94

1

This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following terms best describes the forward reaction in the figure?

Selecione uma das seguintes:

endergonic, ∆G > 0
exergonic, ∆G < 0
endergonic, ∆G < 0
exergonic, ∆G > 0
chemical equilibrium, ∆G = 0

Explicação

Questão 91 de 94

1

The oxygen consumed during cellular respiration is involved directly in which process or event?

Selecione uma das seguintes:

glycolysis
accepting electrons at the end of the electron transport chain
the citric acid cycle
the oxidation of pyruvate to acetyl CoA
the phosphorylation of ADP to form ATP

Explicação

Questão 92 de 94

1

Where are the proteins of the electron transport chain located?

Selecione uma das seguintes:

cytosol
mitochondrial outer membrane
mitochondrial inner membrane
mitochondrial intermembrane space
mitochondrial matrix

Explicação

Questão 93 de 94

1

In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?

Selecione uma das seguintes:

autotrophs and heterotrophs
producers and primary consumers
photosynthesizers
autotrophs
green plants

Explicação

Questão 94 de 94

1

In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during...

Selecione uma das seguintes:

photosynthesis only
respiration only
both photosynthesis and respiration
neither photosynthesis nor respiration

	Criado por Nicole Berozsky quase 9 anos atrás

Quiz questions to study for the final exam.

Biology 111

Questão 1 de 94

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Selecione uma das seguintes:

Explicação

Questão 2 de 94

Selecione uma das seguintes:

Explicação

Questão 3 de 94

Cell membranes are asymmetrical. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

Selecione uma das seguintes:

Explicação

Questão 4 de 94

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups of acetyl CoA molecules. These acetyl groups ________.

Selecione uma das seguintes:

Explicação

Questão 5 de 94

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ______.

Selecione uma das seguintes:

Explicação

Questão 6 de 94

In solution, why do hydrolysis reactions occur more readily than condensation reactions?

Selecione uma das seguintes:

Explicação

Questão 7 de 94

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Selecione uma das seguintes:

Explicação

Questão 8 de 94

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this probably mean?

Selecione uma das seguintes:

Explicação

Questão 9 de 94

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.

Selecione uma das seguintes:

Explicação

Questão 10 de 94

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ______.

Selecione uma das seguintes:

Explicação

Questão 11 de 94

Which of the following processes includes all others?

Selecione uma das seguintes:

Explicação

Questão 12 de 94

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Selecione uma das seguintes:

Explicação

Questão 13 de 94

A localized group of organisms that belong to the same species is called a

Selecione uma das seguintes:

Explicação

Questão 14 de 94

Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into

Selecione uma das seguintes:

Explicação

Questão 15 de 94

The main source of energy for producers in an ecosystem is

Selecione uma das seguintes:

Explicação

Questão 16 de 94

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

Selecione uma das seguintes:

Explicação

Questão 17 de 94

To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology?

Selecione uma das seguintes:

Explicação

Questão 18 de 94

Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of which type of regulation?

Selecione uma das seguintes:

Explicação

Questão 19 de 94

Selecione uma das seguintes:

Explicação

Questão 20 de 94

The elongation of the leading strand during DNA replication

Selecione uma das seguintes:

Explicação