Questions and Answers
What compound directly provides energy for cellular work?
ATP
Which one of the following is true? (Select all that apply)
Which one of the following is true? (Select all that apply)
Which one of the following is most similar to the mechanism of an enzyme inhibitor? (Select all that apply)
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What does diffusion proceed until?
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Facilitated diffusion across a biological membrane requires ______ and moves a substance ______ its concentration gradient.
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How can osmosis be defined?
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The presence of contractile vacuoles in protozoans indicates that the environment ______.
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What process could be responsible for the secretion of a digestive enzyme synthesized by stomach cells?
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Which of the following is most like a signal transduction pathway in a cell? (Select all that apply)
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Humans convert approximately what percentage of the energy stored in food to useful work?
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How is energy transferred from ATP to other molecules?
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Study Notes
Cellular Energy and Enzymes
- ATP is the primary compound that provides energy for cellular work.
- Enzymes specifically catalyze reactions, increasing their rate without being consumed; they are not products or reactants.
- An enzyme's function is heavily dependent on its three-dimensional shape, which determines its specificity and efficiency.
Enzyme Inhibition
- An enzyme inhibitor's mechanism is analogous to blocking someone's parking spot, preventing access and function.
Transport Mechanisms
- Diffusion is a passive process that continues until equilibrium is established, equalizing concentrations across a membrane.
- Facilitated diffusion requires transport proteins to help move substances down their concentration gradient without using energy.
- Osmosis refers specifically to the diffusion of water across a semi-permeable membrane.
Cell Environment and Water Regulation
- Contractile vacuoles in protozoans indicate a hypotonic environment, where water constantly enters the cell, necessitating its removal.
Secretion Processes
- Exocytosis is the process through which certain cells, such as those in the stomach, secrete proteins like digestive enzymes.
Signal Transduction
- A signal transduction pathway in a cell is similar to a person responding to a doorbell, where an external signal prompts a specific internal response.
Energy Conversion Efficiency
- Humans convert around 34% of the energy stored in food into useful work, highlighting limits on energy efficiency in biological systems.
- Energy transfer from ATP to molecules occurs through the transfer of a phosphate group, facilitating various cellular processes.
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Description
Explore the crucial concepts of cellular energy, enzyme functionality, and transport mechanisms in this quiz. Understand the roles of ATP, the importance of enzyme shape, and the processes of diffusion and osmosis. This quiz is essential for students studying cell biology and biochemistry.
