Chapter 1 Flashcards
Who said “Living things are composed of
lifeless molecules.”
Albert Lehninger
who said “…everything that living
things do can be understood
in terms of the jigglings and
wigglings of atoms.”
Richard P. Feynman
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
B) The complex three-dimensional structure of a macromolecule
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
B) The interactions between its monomeric units based on their chemical properties
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) Hydrogen bonds between polar side chains
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) The primary structure of the protein
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.
B) The environment around the protein, such as pH or temperature, can affect the interactions between monomeric units.
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
D) Covalent bonding between different amino acids within the protein
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.
C) It disrupts the conformation of the protein, leading to loss of function.
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
B) The pH of the environment surrounding the DNA
It is made out of Long chains of 20 kinds of amino acids
protein
what is made out of long & short chains of nucleic acid bases form DNA, RNA, also ATP, GTP
Nucleic Acid
it made out of phosphate or other charged “head” with long hydro-caron tail
Lipid
Long & short chains of sugar molecules like glucose and fructose
Carbohydrates
its function is an information storage (RNA, DNA), structure, enzymes, energy transfer
nucleic acid
Its function is most of the structure and function of living things; enzymes
protein
it is made out of various molecules such as hormones, vitamins, neurotransmitters, porphyrins
Small molecules
its function is energy storage insulation cushioning membranes
lipid
its function is energy source energy storage structure
carbohydrates
its function is mostly to send signals
small molecules
Living systems transform energy exclusively through catabolic reactions.
True / False
False
Explanation: Living systems transform energy through both catabolic (breaking down molecules) and anabolic (building up molecules) reactions.
All energy transformations in living systems result in the production of heat as a byproduct.
True / False
True
Explanation: During energy transformations in living systems, some energy is inevitably lost as heat due to the second law of thermodynamics.
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
C) Special energized biomolecules that provide power for cellular work
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
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
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
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
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
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.
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.
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
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
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
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
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.
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
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.
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
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.
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.
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
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
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.
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
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.
Simple division in bacteria is an example of:
A) Sexual reproduction
B) Asexual reproduction
C) Genetic recombination
D) Spontaneous mutation
B) Asexual reproduction
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.
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.
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.
refers to the accuracy and precision with which something is replicated, transmitted, or reproduced.
- High degree of fidelity
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.
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.
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