Chapter 1 Flashcards
(139 cards)
1
Q
Who said “Living things are composed of
lifeless molecules.”
A
Albert Lehninger
2
Q
who said “…everything that living
things do can be understood
in terms of the jigglings and
wigglings of atoms.”
A
Richard P. Feynman
3
Q
Which of the following best describes the term “conformation” of a macromolecule?
A) The sequence of amino acids in a protein
B) The complex three-dimensional structure of a macromolecule
C) The linear arrangement of nucleotides in a DNA strand
D) The number of monomeric units in a polymer
A
B) The complex three-dimensional structure of a macromolecule
4
Q
The conformation of a macromolecule is primarily determined by which of the following factors?
A) The type of solvent in which the macromolecule is dissolved
B) The interactions between its monomeric units based on their chemical properties
C) The overall size of the macromolecule
D) The concentration of the macromolecule in solution
A
B) The interactions between its monomeric units based on their chemical properties
5
Q
Which type of interaction is most likely to stabilize the conformation of a protein?
A) Hydrogen bonds between polar side chains
B) Ionic bonds between hydrophobic side chains
C) Covalent bonds between adjacent monomeric units
D) Van der Waals interactions between distant amino acids
A
A) Hydrogen bonds between polar side chains
6
Q
The folding of a protein into its functional conformation is largely dependent on:
A) The primary structure of the protein
B) The concentration of proteins in the cell
C) The presence of DNA in the nucleus
D) The rate of protein synthesis
A
A) The primary structure of the protein
7
Q
Which of the following best explains why certain proteins can change their conformation?
A) Proteins can be degraded and re-synthesized with a different sequence.
B) The environment around the protein, such as pH or temperature, can affect the interactions between monomeric units.
C) The protein’s conformation is fixed and cannot change once it is folded.
D) Proteins interact with DNA to change their conformation.
A
B) The environment around the protein, such as pH or temperature, can affect the interactions between monomeric units.
8
Q
Which of the following interactions is least likely to contribute to the stabilization of a protein’s conformation?
A) Hydrophobic interactions between nonpolar side chains
B) Disulfide bonds between cysteine residues
C) Ionic interactions between charged side chains
D) Covalent bonding between different amino acids within the protein
A
D) Covalent bonding between different amino acids within the protein
9
Q
Which of the following is true about the denaturation of a protein?
A) It involves the breaking of peptide bonds within the protein backbone.
B) It leads to a change in the primary sequence of the protein.
C) It disrupts the conformation of the protein, leading to loss of function.
D) It is a reversible process that restores the protein to its original conformation.
A
C) It disrupts the conformation of the protein, leading to loss of function.
10
Q
A change in which of the following factors is most likely to affect the conformation of a DNA molecule?
A) The concentration of ribosomes in the cell
B) The pH of the environment surrounding the DNA
C) The number of nucleotides in the DNA strand
D) The presence of polysaccharides in the cell
A
B) The pH of the environment surrounding the DNA
11
Q
It is made out of Long chains of 20 kinds of amino acids
A
protein
12
Q
what is made out of long & short chains of nucleic acid bases form DNA, RNA, also ATP, GTP
A
Nucleic Acid
13
Q
it made out of phosphate or other charged “head” with long hydro-caron tail
A
Lipid
13
Q
Long & short chains of sugar molecules like glucose and fructose
A
Carbohydrates
14
Q
its function is an information storage (RNA, DNA), structure, enzymes, energy transfer
A
nucleic acid
14
Q
A
15
Q
Its function is most of the structure and function of living things; enzymes
A
protein
16
Q
it is made out of various molecules such as hormones, vitamins, neurotransmitters, porphyrins
A
Small molecules
17
Q
its function is energy storage insulation cushioning membranes
A
lipid
18
Q
its function is energy source energy storage structure
A
carbohydrates
19
Q
its function is mostly to send signals
A
small molecules
20
Q
Living systems transform energy exclusively through catabolic reactions.
True / False
A
False
Explanation: Living systems transform energy through both catabolic (breaking down molecules) and anabolic (building up molecules) reactions.
21
Q
All energy transformations in living systems result in the production of heat as a byproduct.
True / False
A
True
Explanation: During energy transformations in living systems, some energy is inevitably lost as heat due to the second law of thermodynamics.
22
Q
Which of the following best describes ATP and NADPH in the context of cellular processes?
A) Structural components of the cell membrane
B) Genetic information carriers
C) Special energized biomolecules that provide power for cellular work
D) Enzymes that catalyze biochemical reactions
A
C) Special energized biomolecules that provide power for cellular work
23
Which of the following is NOT a process powered by ATP in living organisms?
A) Muscle contraction (movement)
B) Osmotic work against concentration gradients
C) Light emission in bioluminescent organisms
D) Passive diffusion of small molecules across the membrane
D) Passive diffusion of small molecules across the membrane
23
TP and NADPH are primarily involved in which of the following cellular processes?
A) Transport of oxygen in the blood
B) Transmission of nerve impulses
C) Powering biosynthesis, movement, osmotic work, and light emission
D) DNA replication and repair
C) Powering biosynthesis, movement, osmotic work, and light emission
23
NADPH is primarily used in which of the following cellular processes?
A) Oxidative phosphorylation in the mitochondria
B) The light-dependent reactions of photosynthesis
C) Muscle contraction
D) Degradation of fatty acids
B) The light-dependent reactions of photosynthesis
24
During biosynthesis, ATP provides the energy required to:
A) Break down complex molecules into simpler ones
B) Assemble monomers into polymers like proteins and nucleic acids
C) Transport ions across cell membranes without using energy
D) Store genetic information in the nucleus
B) Assemble monomers into polymers like proteins and nucleic acids
24
Light emission in bioluminescent organisms is driven by:
A) The breakdown of glucose in the cytoplasm
B) The oxidation of NADPH directly releasing photons
C) The energy provided by ATP in the luciferase reaction
D) The passive flow of electrons through the mitochondrial membrane
C) The energy provided by ATP in the luciferase reaction
25
Which of the following accurately describes the role of NADPH in anabolic reactions?
A) NADPH acts as an electron donor, reducing other molecules during biosynthesis.
B) NADPH breaks down into ADP and inorganic phosphate to release energy.
C) NADPH is hydrolyzed to release energy directly for cellular movement.
D) NADPH is only used in catabolic reactions to break down molecules.
A) NADPH acts as an electron donor, reducing other molecules during biosynthesis.
26
ATP is crucial in cellular movement because:
A) It provides the energy for the formation of microtubules.
B) It directly fuels the sliding of actin and myosin filaments in muscle contraction.
C) It transports motor proteins along the cytoskeleton without energy.
D) It causes depolarization of the cell membrane without involving other ions.
B) It directly fuels the sliding of actin and myosin filaments in muscle contraction.
27
n which of the following processes does ATP NOT play a direct role?
A) Synthesis of DNA and RNA
B) Facilitating the movement of flagella or cilia
C) Oxidative phosphorylation
D) Photosynthetic light-independent reactions (Calvin cycle)
C) Oxidative phosphorylation
28
What is the condition of inanimate matter in terms of thermodynamics?
A) Minimum entropy
B) Maximum order
C) Increasing disorder or maximum entropy
D) Decreasing disorder or minimum entropy
C) Increasing disorder or maximum entropy
29
Which of the following best describes the "steady state" in living organisms?
A) A state of complete equilibrium with the environment
B) A state where energy and material are consumed to maintain stability and order
C) A condition where no energy is exchanged with the environment
D) A state of maximum entropy within the organism
B) A state where energy and material are consumed to maintain stability and order
30
31
How do living organisms maintain order and stability?
A) By isolating themselves from their environment
B) By extracting free energy from the environment and exporting entropy as heat
C) By minimizing energy consumption and conserving resources
D) By reaching equilibrium with the environment as quickly as possible
B) By extracting free energy from the environment and exporting entropy as heat
32
Which of the following statements about entropy and living organisms is true?
A) Living organisms decrease their internal entropy without any external energy input.
B) Living organisms reach maximum entropy during their life span.
C) Living organisms export entropy to maintain low internal entropy.
D) Living organisms avoid entropy altogether by maintaining perfect order.
C) Living organisms export entropy to maintain low internal entropy.
33
At what point does an organism reach equilibrium with its inanimate environment?
A) During periods of intense physical activity
B) When it is in a steady state
C) Upon death
D) When it reaches its maximum growth potential
C) Upon death
34
What happens to the entropy of an organism after death?
A) It decreases as the organism decomposes.
B) It remains the same as during life.
C) It increases as the organism reaches equilibrium with its environment.
D) It fluctuates depending on environmental conditions.
C) It increases as the organism reaches equilibrium with its environment.
35
The living state is characterized by which of the following?
A) A lack of energy flow through the organism
B) A constant flow of energy through the organism
C) No exchange of energy with the environment
D) Maximum entropy within the organism
B) A constant flow of energy through the organism
36
Why is the flow of energy crucial for living organisms?
A) It allows them to reach maximum entropy quickly.
B) It enables them to maintain stability and avoid equilibrium with the environment.
C) It ensures they conserve all energy within their cells.
D) It prevents the organism from losing any heat to the environment.
B) It enables them to maintain stability and avoid equilibrium with the environment.
37
What distinguishes living systems from the inanimate world in terms of replication?
A) Living systems have no capacity for replication.
B) Living systems rely on external forces for replication.
C) Living systems have a remarkable capacity for self-replication.
D) Both living and inanimate systems can self-replicate under certain condition
C) Living systems have a remarkable capacity for self-replication.
38
Which of the following is an example of self-replication in living organisms?
A) Crystallization of salt from a solution
B) Simple division in bacteria
C) Erosion of rocks over time
D) Formation of raindrops from water vapor
B) Simple division in bacteria
39
Sexual reproduction in plants and animals involves:
A) The replication of identical genetic material without variation
B) The combination of genetic material from two parents to create a genetically unique offspring
C) The splitting of a single organism into two identical copies
D) The synthesis of inorganic molecules
B) The combination of genetic material from two parents to create a genetically unique offspring
40
What is the significance of self-replication in living systems?
A) It allows living systems to grow, evolve, and perpetuate their species.
B) It leads to the gradual decay of organisms over time.
C) It ensures that living systems remain in a state of stasis.
D) It prevents any form of genetic variation within a population.
A) It allows living systems to grow, evolve, and perpetuate their species.
40
Which of the following processes in living systems contributes to genetic diversity?
A) Simple division in bacteria
B) Sexual reproduction in plants and animals
C) Replication of DNA without error
D) Spontaneous replication of inorganic molecules
B) Sexual reproduction in plants and animals
40
Which of the following statements is true regarding molecules of the inanimate world and their ability to replicate?
A) Molecules of the inanimate world can self-replicate under the right conditions.
B) Inanimate molecules have no inherent capacity for self-replication.
C) Inanimate molecules replicate by undergoing spontaneous chemical reactions.
D) Inanimate molecules replicate similarly to living organisms.
B) Inanimate molecules have no inherent capacity for self-replication.
41
Simple division in bacteria is an example of:
A) Sexual reproduction
B) Asexual reproduction
C) Genetic recombination
D) Spontaneous mutation
B) Asexual reproduction
41
Why is self-replication an important feature of living organisms?
A) It ensures the survival and continuity of life through generations.
B) It prevents any changes in the genetic makeup of organisms.
C) It causes organisms to rapidly degrade and become inanimate.
D) It is only important for single-celled organisms and not for multicellular organisms.
A) It ensures the survival and continuity of life through generations.
42
What role does DNA play in the self-replication of living organisms?
A) It acts as a template for the synthesis of new molecules during replication.
B) It provides energy for cellular metabolism.
C) It directs the formation of inorganic crystals.
D) It regulates the water content in cells.
A) It acts as a template for the synthesis of new molecules during replication.
43
In which of the following ways do living systems differ fundamentally from inanimate systems?
A) Living systems can replicate their genetic material and produce offspring.
B) Living systems exist in a state of maximum entropy.
C) Living systems do not require energy input to maintain their functions.
D) Living systems are composed entirely of inorganic molecules.
A) Living systems can replicate their genetic material and produce offspring.
44
refers to the accuracy and precision with which something is replicated, transmitted, or reproduced.
- High degree of fidelity
45
True or False: The elements hydrogen (H), oxygen (O), carbon (C), and nitrogen (N) collectively account for more than 99% of the atoms in the human body, with nitrogen being the most abundant by number of atoms.
Answer: False
Explanation: While it's true that H, O, C, and N make up over 99% of the atoms in the human body, hydrogen is actually the most abundant by number of atoms, not nitrogen.
45
hich statement is true about the covalent bonding capabilities of C, N, and O in the context of biological molecules?
A) C, N, and O can only form single bonds with hydrogen.
B) C, N, and O cannot form bonds with each other in biological molecules.
C) C, N, and O can form double bonds with each other, increasing chemical versatility.
D) C, N, and O are unable to participate in electron-pair sharing.
C) C, N, and O can form double bonds with each other, increasing chemical versatility.
45
What key property of H, O, C, and N makes them essential to the chemistry of life?
A) Their ability to dissolve in water
B) Their ability to form covalent bonds by electron-pair sharing
C) Their ability to ionize easily in biological systems
D) Their low atomic mass
B) Their ability to form covalent bonds by electron-pair sharing
45
Which of the following elements can share two electron pairs to form double bonds, enhancing their chemical versatility in biomolecules?
A) Hydrogen (H)
B) Carbon (C), Nitrogen (N), and Oxygen (O)
C) Helium (He), Neon (Ne), and Argon (Ar)
D) Phosphorus (P), Sulfur (S), and Chlorine (Cl)
B) Carbon (C), Nitrogen (N), and Oxygen (O)
46
Why is carbon (C) particularly important in the formation of a variety of biological molecules?
A) Carbon can only form single bonds with other elements.
B) Carbon can form covalent bonds with itself, creating linear, branched, and cyclic compounds.
C) Carbon is highly reactive and unstable, which drives many biochemical reactions.
D) Carbon has a high atomic number, making it a heavy and stable element.
C) Carbon is highly reactive and unstable, which drives many biochemical reactions.
47
The tetrahedral shape of carbon (C) bonds is significant because:
A) It limits carbon to forming only simple molecules.
B) It allows for the formation of complex and diverse organic structures.
C) It prevents carbon from forming double bonds with other atoms.
D) It makes carbon inert and unreactive in biological systems.
B) It allows for the formation of complex and diverse organic structures.
48
Which of the following explains the significance of carbon's covalent bonding ability in the context of life?
A) Carbon forms the least stable bonds in biological systems.
B) Carbon's ability to form four covalent bonds allows for the creation of diverse molecular structures.
C) Carbon can only bond with oxygen in biological molecules.
D) Carbon's bonding capacity is similar to that of inert gases.
B) Carbon's ability to form four covalent bonds allows for the creation of diverse molecular structures.
49
Which element is known for forming double bonds in biological systems, enhancing the diversity of biomolecules?
A) Helium (He)
B) Nitrogen (N)
C) Sodium (Na)
D) Magnesium (Mg)
B) Nitrogen (N)
50
Which of the following is NOT considered an inorganic precursor in the structural hierarchy of biomolecules?
A) Water (H2O)
B) Carbon dioxide (CO2)
C) Glucose (C6H12O6)
D) Ammonium (NH4+)
C) Glucose (C6H12O6)
50
What is the role of hydrogen in the context of forming covalent bonds in biological molecules?
A) Hydrogen is too small to form covalent bonds.
B) Hydrogen forms covalent bonds that stabilize larger molecules.
C) Hydrogen forms double bonds with carbon and oxygen.
D) Hydrogen does not participate in covalent bonding.
B) Hydrogen forms covalent bonds that stabilize larger molecules.
51
Which of the following best describes the role of inorganic precursors in the formation of biomolecules?
A) They are the final products of metabolic processes.
B) They are simple molecules that serve as the building blocks for more complex structures.
C) They are complex structures that break down into simple molecules.
D) They do not participate in the formation of biomolecules.
B) They are simple molecules that serve as the building blocks for more complex structures.
52
Which of the following is true about the relationship between inorganic precursors and metabolites?
A) Metabolites are converted directly into inorganic precursors.
B) Inorganic precursors are transformed into metabolites through metabolic processes.
C) Metabolites are used to synthesize inorganic precursors.
D) Inorganic precursors do not participate in the formation of metabolites.
B) Inorganic precursors are transformed into metabolites through metabolic processes.
53
Which of the following pairs correctly matches an inorganic precursor with its corresponding role in biomolecule formation?
A) Dinitrogen (N2) - Energy storage
B) Ammonium (NH4+) - Source of nitrogen for amino acids
C) Water (H2O) - Main source of carbon in organic molecules
D) Carbon dioxide (CO2) - Major component of nucleic acids
B) Ammonium (NH4+) - Source of nitrogen for amino acids
53
In the context of biomolecular structure, what is the correct sequence from simplest to most complex?
A) Metabolites → Inorganic precursors → Biomolecules
B) Inorganic precursors → Metabolites → Complex biomolecules
C) Biomolecules → Inorganic precursors → Metabolites
D) Complex biomolecules → Metabolites → Inorganic precursors
B) Inorganic precursors → Metabolites → Complex biomolecules
54
Which of the following inorganic precursors is most directly involved in photosynthesis?
A) Nitrate (NO3-)
B) Water (H2O)
C) Ammonium (NH4+)
D) Dinitrogen (N2)
B) Water (H2O)
55
What role does carbon dioxide (CO2) play in the structural hierarchy of biomolecules?
A) It serves as an energy storage molecule.
B) It is an inorganic precursor used in the synthesis of organic molecules.
C) It is a waste product that is expelled from cells.
D) It forms the backbone of nucleic acids.
B) It is an inorganic precursor used in the synthesis of organic molecules.
56
Which of the following processes involves the transformation of inorganic precursors into more complex biomolecules?
A) Glycolysis
B) Photosynthesis
C) Fermentation
D) Hydrolysis
B) Photosynthesis
57
The transformation of inorganic precursors into metabolites is crucial for which of the following biological processes?
A) Protein folding
B) DNA replication
C) Cellular respiration
D) Biomolecule synthesis
D) Biomolecule synthesis
58
Which of the following best describes the role of metabolites in cellular processes?
A) Metabolites are large macromolecules that store genetic information.
B) Metabolites are simple organic compounds that act as intermediates in energy transformation and biosynthesis.
C) Metabolites are complex carbohydrates that provide structural support to cells.
D) Metabolites are inorganic molecules that are directly involved in photosynthesis.
B) Metabolites are simple organic compounds that act as intermediates in energy transformation and biosynthesis.
58
Which of the following are NOT considered building blocks that are synthesized from metabolites?
A) Amino acids
B) Polysaccharides
C) Fatty acids
D) Nucleotides
B) Polysaccharides
Explanation: Polysaccharides are macromolecules formed from simple sugars (which are metabolites), not directly considered building blocks. The building blocks include amino acids, fatty acids, and nucleotides.
58
Which inorganic precursor is most directly associated with the nitrogen cycle in living organisms?
A) Carbon dioxide (CO2)
B) Dinitrogen (N2)
C) Water (H2O)
D) Glucose (C6H12O6)
B) Dinitrogen (N2)
59
Which of the following is a correct sequence from metabolites to macromolecules?
A) Sugars → Polysaccharides → Glucose
B) Fatty acids → Lipids → Glycerol
C) Amino acids → Proteins → Polysaccharides
D) Nucleotides → Polynucleotides (DNA/RNA) → Genetic material
D) Nucleotides → Polynucleotides (DNA/RNA) → Genetic material
60
Which of the following pairs correctly matches a metabolite with its associated macromolecule?
A) Glycerol - Polysaccharides
B) Sugars - Proteins
C) Amino acids - Proteins
D) Fatty acids - DNA
C) Amino acids - Proteins
61
The process of converting simple sugars into polysaccharides is an example of:
A) Catabolism
B) Anabolism
C) Hydrolysis
D) Dehydration
B) Anabolism
61
Which of the following is NOT a type of non-covalent interaction that contributes to the formation of supramolecular complexes?
A) Hydrogen bonds
B) Ionic attractions
C) Covalent bonds
D) Van der Waals forces
C) Covalent bonds
62
Which of the following organelles is NOT considered part of the biomolecular hierarchy of a cell?
A) Chloroplast
B) Endoplasmic reticulum
C) Peroxisome
D) Ribosome
D) Ribosome
63
Which of the following is an example of a supramolecular complex?
A) Nucleus
B) Mitochondria
C) Ribosome
D) Chromoplast
C) Ribosome
63
Supramolecular complexes, such as ribosomes and cytoskeletons, are formed through:
A) Covalent bonding
B) Non-covalent interactions
C) Polymerization of monomers
D) Enzymatic reactions
B) Non-covalent interactions
64
Which of the following statements about membranes is TRUE?
A) Membranes are solely composed of covalently bonded lipids.
B) Membranes are easily classified as either supramolecular assemblies or organelles.
C) Membranes are defined by non-covalent forces between proteins and lipids.
D) Membranes only serve to compartmentalize genetic material within cells.
C) Membranes are defined by non-covalent forces between proteins and lipids.
64
The formation of multi-functional enzyme complexes is primarily driven by:
A) Covalent bonding between enzymes
B) Hydrophobic interactions among enzymes
C) The fusion of organelles
D) The transcription of genetic material
B) Hydrophobic interactions among enzymes
65
In the biomolecular hierarchy, which of the following is a characteristic of organelles?
A) They are formed entirely through non-covalent interactions.
B) They are generally smaller than supramolecular complexes.
C) They are distinct entities within cells, often enclosed by membranes.
D) They include structures like chromosomes and ribosomes.
Answer: C) They are distinct entities within cells, often enclosed by membranes.
66
Membranes in cells are best described as:
A) Simple lipid bilayers with no proteins.
B) Supramolecular assemblies with both protein and lipid components.
C) Organelles that are purely proteinaceous.
D) Structures solely responsible for energy production.
B) Supramolecular assemblies with both protein and lipid components.
67
Which organelle is specifically involved in the synthesis of proteins and is associated with ribosomes?
A) Nucleus
B) Endoplasmic reticulum
C) Lysosome
D) Peroxisome
B) Endoplasmic reticulum
68
Hydrophobic interactions within a cell contribute to:
A) The formation of covalent bonds between organelles
B) The creation of discrete compartments or volumes within cells
C) The fusion of cell membranes
D) The replication of genetic material
B) The creation of discrete compartments or volumes within cells
68
Which of the following interactions is the weakest yet still contributes to the formation of supramolecular complexes?
A) Covalent bonds
B) Hydrogen bonds
C) Ionic attractions
D) Van der Waals forces
D) Van der Waals forces
69
Which of the following is TRUE regarding the membranes of organelles?
A) All organelle membranes have the same lipid and protein composition.
B) The membranes of organelles, such as mitochondria and chloroplasts, have unique compositions suited to their functions.
C) Organelle membranes do not contribute to the function of the organelle.
D) The protein composition of organelle membranes is irrelevant to their function.
B) The membranes of organelles, such as mitochondria and chloroplasts, have unique compositions suited to their functions.
70
The formation of compartments within cells due to hydrophobic interactions is essential because:
A) It allows for the random mixing of cellular contents.
B) It provides a barrier that protects organelles from external damage.
C) It enables distinct biochemical environments necessary for organelle function.
D) It reduces the need for cellular membranes.
C) It enables distinct biochemical environments necessary for organelle function.
71
Which of the following is a consequence of hydrophobic interactions in cellular membranes?
A) The increase in covalent bonding within the cell
B) The fusion of different organelles
C) The maintenance of organelle structure and function
D) The dissolution of membranes in aqueous environments
C) The maintenance of organelle structure and function
72
Why do organelle membranes differ from one another in terms of their protein and lipid composition?
A) To ensure all organelles perform the same function
B) To support the specific functions of each organelle
C) To create a uniform environment within the cell
D) To prevent any interaction between different organelles
B) To support the specific functions of each organelle
73
Which organelle is likely to have a membrane rich in proteins involved in energy production?
A) Nucleus
B) Golgi apparatus
C) Mitochondria
D) Lysosome
C) Mitochondria
74
Hydrophobic interactions within cell membranes primarily contribute to:
A) The dissolution of membranes in water
B) The creation of stable, non-aqueous environments within cells
C) The formation of covalent bonds between lipids
D) The destruction of cellular compartments
B) The creation of stable, non-aqueous environments within cells
75
Which statement best describes the role of lipid bilayers in cellular membranes?
A) They allow for free movement of all molecules across the membrane.
B) They create hydrophilic environments within the membrane.
C) They form barriers that regulate the passage of substances into and out of organelles.
D) They are composed entirely of proteins with no lipid components.
Answer: C) They form barriers that regulate the passage of substances into and out o
76
Which of the following statements about organelle membranes is FALSE?
A) Organelles like chloroplasts and mitochondria have membranes with distinct lipid and protein compositions.
B) The function of an organelle is independent of its membrane composition.
C) Organelle membranes create unique environments for specific biochemical reactions.
D) The membrane composition of an organelle is tailored to its specific function.
B) The function of an organelle is independent of its membrane composition.
77
What is the primary reason that hydrophobic interactions are important in the formation of cellular compartments?
A) They allow for the spontaneous mixing of all cellular components.
B) They enable the formation of stable, non-covalent structures that segregate cellular processes.
C) They promote the covalent bonding of all cellular molecules.
D) They lead to the breakdown of membranes under stress.
B) They enable the formation of stable, non-covalent structures that segregate cellular processes.
78
What is one key property of biomolecules that contributes to their fitness as components of living systems?
A) The ability to form random, disorganized structures
B) The capacity to store and transmit information essential for life
C) The inability to interact with other biomolecules
D) The lack of directionality in their structure
B) The capacity to store and transmit information essential for life
79
Which of the following attributes of biomolecules is critical for the maintenance of the living state?
A) Random energy absorption from the environment
B) The capacity to abstract energy from the environment in an orderly manner
C) The storage of energy without any organized mechanism
D) The inability to interact with environmental factors
B) The capacity to abstract energy from the environment in an orderly manner
80
Why is directionality considered an important property of biological macromolecules?
A) It prevents them from interacting with other molecules.
B) It allows for the organized synthesis of structures essential for life.
C) It leads to the random assembly of cellular components.
D) It restricts their ability to function in living systems.
B) It allows for the organized synthesis of structures essential for life.
81
The necessity for information and energy in living systems implies that biomolecules must:
A) Be capable of interacting with one another to carry out life processes
B) Remain isolated from each other to maintain order
C) Avoid storing or using energy
D) Function without any information transmission
A) Be capable of interacting with one another to carry out life processes
82
What characteristic of biological macromolecules makes them potential carriers of information?
A) The simplicity and repetitiveness of their units
B) The diversity and order of their units
C) The lack of any specific structure
D) Their inability to interact with other molecules
B) The diversity and order of their units
82
Which statement best describes the relationship between biomolecules and energy in living systems?
A) Biomolecules generate energy randomly without any specific mechanism.
B) Biomolecules must utilize an orderly mechanism to abstract energy from the environment.
C) Energy plays no role in the function of biomolecules.
D) Biomolecules are only capable of storing energy, not using it.
B) Biomolecules must utilize an orderly mechanism to abstract energy from the environment.
82
In what way does the "sense" or directionality of biomolecules contribute to their fitness in living systems?
A) It leads to the disorganized function of cellular components.
B) It supports the precise and ordered assembly of biological structures.
C) It limits their ability to replicate or grow.
D) It prevents the storage of information necessary for life.
B) It supports the precise and ordered assembly of biological structures.
83
Which property of biomolecules is essential for the processes of life to occur?
A) The capacity to contain and transmit life-essential information
B) The inability to store or use energy
C) The formation of disorganized structures
D) The absence of directionality in their formation
A) The capacity to contain and transmit life-essential information
84
Why is the capacity to translate information a critical property of certain biomolecules?
A) It allows biomolecules to exist in a random state.
B) It enables the synthesis of organized structures necessary for life.
C) It prevents interaction between different biomolecules.
D) It eliminates the need for energy in cellular processes
B) It enables the synthesis of organized structures necessary for life.
85
Which statement correctly describes the necessity of biomolecules to interact with one another?
A) Biomolecular interactions are unnecessary for life processes.
B) Interactions between biomolecules are essential for the processes of life.
C) Biomolecules function best in isolation.
D) Interactions between biomolecules lead to disorder.
B) Interactions between biomolecules are essential for the processes of life.
86
The maintenance of the living state requires biomolecules to:
A) Remain in a static, unchanging state
B) Actively engage in energy transformation and information transmission
C) Avoid interactions with other cellular components
D) Store energy without using it
B) Actively engage in energy transformation and information transmission
87
Which property of biological macromolecules is essential for their role in living systems?
A) The ability to form random, disorganized structures
B) The characteristic three-dimensional architecture
C) The inability to interact with other molecules
D) Their uniform and repetitive structure
B) The characteristic three-dimensional architecture
88
Van der Waals forces result from:
A) Strong covalent bonds between atoms
B) Induced electrical interactions between closely approaching atoms or molecules
C) Permanent ionic bonds between charged atoms
D) Gravitational forces between large biomolecules
B) Induced electrical interactions between closely approaching atoms or molecules
88
Why are weak forces, such as van der Waals forces, important in biological systems?
A) They prevent any interactions between biomolecules.
B) They maintain the structure and determine interactions among biomolecules.
C) They are too weak to have any significant effect on biological processes.
D) They operate over long distances, affecting multiple molecules at once.
B) They maintain the structure and determine interactions among biomolecules.
88
Which of the following statements about van der Waals forces is correct?
A) They operate over large interatomic distances.
B) They are effective only over very limited interatomic distances (0.3 to 0.6 nm).
C) They result from permanent dipole interactions.
D) They involve the sharing of electron pairs between atoms.
B) They are effective only over very limited interatomic distances (0.3 to 0.6 nm).
89
What determines the ability of biomolecules to act as carriers of information?
A) Their ability to form covalent bonds exclusively
B) The diversity and complexity of their structural units
C) The absence of any three-dimensional structure
D) The uniformity and simplicity of their units
B) The diversity and complexity of their structural units
90
The three-dimensional architecture of biomolecules is important because:
A) It allows them to interact with specific target molecules in a precise manner.
B) It restricts them from interacting with other biomolecules.
C) It simplifies their function in biological systems.
D) It has no impact on their function.
A) It allows them to interact with specific target molecules in a precise manner.
91
Which of the following best explains why biomolecules are not overly repetitive or simple?
A) Because simplicity is necessary for their stability
B) To allow them to store complex information and perform various functions
C) To prevent them from interacting with other molecules
D) Because simplicity leads to more efficient interactions
B) To allow them to store complex information and perform various functions
92
How do van der Waals forces contribute to the stability of biological structures?
A) By forming strong, permanent bonds between atoms
B) By providing weak, transient interactions that stabilize biomolecular structures
C) By repelling atoms and preventing them from interacting
D) By creating large, rigid structures
B) By providing weak, transient interactions that stabilize biomolecular structures
93
Why are weak forces such as van der Waals forces crucial for biomolecular interactions despite their limited strength?
A) They act over large distances and affect multiple molecules simultaneously.
B) They provide the necessary flexibility and dynamism to biological structures.
C) They are stronger than covalent bonds and form the backbone of biomolecules.
D) They have no significant role in biological interactions.
B) They provide the necessary flexibility and dynamism to biological structures.
94
Which of the following best describes the formation of a hydrogen bond?
A) Between two hydrogen atoms bonded to different electronegative atoms
B) Between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom that serves as a hydrogen bond acceptor
C) Between two oxygen atoms in close proximity
D) Between a hydrogen atom and a non-electronegative atom
B) Between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom that serves as a hydrogen bond acceptor
95
What characteristic of hydrogen bonds makes them highly directional?
A) The spherical symmetry of the involved atoms
B) The cylindrical symmetry and straight alignment between the donor, hydrogen, and acceptor atoms
C) The random orientation of hydrogen bonds
D) The lack of a fixed position for the hydrogen bond
B) The cylindrical symmetry and straight alignment between the donor, hydrogen, and acceptor atoms
96
Which of the following correctly describes ionic interactions?
A) Attractive forces between two neutral molecules
B) Attractive forces between oppositely charged structures
C) Attractive forces between two hydrogen atoms
D) Repulsive forces between similarly charged structures
B) Attractive forces between oppositely charged structures
96
How do ionic interactions differ from hydrogen bonds in terms of directionality?
A) Ionic interactions are more directional than hydrogen bonds.
B) Ionic interactions lack the directionality that is characteristic of hydrogen bonds.
C) Both ionic interactions and hydrogen bonds have similar directionality.
D) Ionic interactions and hydrogen bonds are both non-directional.
B) Ionic interactions lack the directionality that is characteristic of hydrogen bonds.
97
Why might ionic interactions lack the precise fit found in van der Waals interactions?
A) Because ionic interactions involve weak forces
B) Because the electrical charge in ionic interactions is radially distributed
C) Because ionic interactions are only temporary
D) Because ionic interactions do not involve any charges
B) Because the electrical charge in ionic interactions is radially distributed
97
Which of the following scenarios would most likely result in an ionic interaction?
A) Interaction between a hydrogen atom and a carbon atom
B) Interaction between two hydrogen atoms bonded to electronegative atoms
C) Interaction between a positively charged ion and a negatively charged ion
D) Interaction between two nonpolar molecules
C) Interaction between a positively charged ion and a negatively charged ion
98
What role do permanent dipoles play in ionic interactions?
A) They repel other molecules, preventing interactions.
B) They enhance the directionality of hydrogen bonds.
C) They contribute to the separation of positive and negative charges, facilitating ionic interactions.
D) They create hydrogen bonds between molecules.
C) They contribute to the separation of positive and negative charges, facilitating ionic interactions.
99
What is an example of an induced dipole in the context of ionic interactions?
A) A molecule with a fixed positive and negative charge separation
B) A molecule that temporarily develops a separation of positive and negative charges due to environmental influence
C) A nonpolar molecule with no charge separation
D) A molecule that permanently retains its charge separation
B) A molecule that temporarily develops a separation of positive and negative charges due to environmental influence
99
Which of the following correctly pairs a molecular interaction with its defining characteristic?
A) Van der Waals interactions - high directionality
B) Hydrogen bonds - radially distributed charge
C) Ionic interactions - permanent dipole formation
D) Hydrogen bonds - formation between a hydrogen atom and an electronegative atom
D) Hydrogen bonds - formation between a hydrogen atom and an electronegative atom
100
Which interaction is most likely to occur between a hydrogen atom in water (H2O) and an oxygen atom in a nearby water molecule?
A) Ionic interaction
B) Covalent bond
C) Hydrogen bond
D) Van der Waals force
C) Hydrogen bond
101
What is the primary driving force behind hydrophobic interactions in biological systems?
A) The attraction between nonpolar molecules and water
B) The strong tendency of water to exclude nonpolar groups or molecules
C) The formation of covalent bonds between nonpolar molecules
D) The ionic attraction between polar molecules
B) The strong tendency of water to exclude nonpolar groups or molecules
102
What happens to the entropy of water when hydrophobic interactions are not present?
A) The entropy of water decreases
B) The entropy of water remains unchanged
C) The entropy of water is raised due to the orderly arrangement of water molecules
D) The entropy of water is raised because fewer water molecules are arranged in orderly arrays
D) The entropy of water is raised because fewer water molecules are arranged in orderly arrays
102
Which of the following best describes "molecular recognition through structural complementarity" in biochemistry?
A) The ability of biomolecules to randomly interact with one another
B) The ability of biomolecules to recognize and interact with one another in very specific ways due to their complementary structures
C) The formation of covalent bonds between complementary molecules
D) The non-specific interactions between different biomolecules
B) The ability of biomolecules to recognize and interact with one another in very specific ways due to their complementary structures
103
Which example best illustrates a specific molecular recognition mechanism based on structural complementarity?
A) A lipid interacting with water
B) A protein recognizing its specific metabolite
C) A sugar molecule dissolving in water
D) A metal ion binding to a chloride ion
B) A protein recognizing its specific metabolite
104
What role does the Juno-Izumo interaction play in fertilization?
A) It promotes the fusion of multiple sperm with the egg
B) It prevents the binding of sperm to the egg
C) It is essential for the initial binding of sperm to the egg and may help prevent polyspermy
D) It inhibits the formation of nonviable polyploid embryos
C) It is essential for the initial binding of sperm to the egg and
105
the ordered reaction
pathways by which cellular chemistry
proceeds and biological energy
transformations are accomplished
Metabolism
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