Questions and Answers
Which of the following do mitochondria and chloroplasts have in common?
Which of the following processes includes all others: osmosis, diffusion of a solute across a membrane, facilitated diffusion, and transport of an ion down its electrochemical gradient?
Which of the following are functions of the cytoskeleton?
Which of the following is incorrect about the extracellular matrix?
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Which of the following is correct about the extracellular matrix?
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Which one of the following molecules is most likely to diffuse freely across the lipid bilayer of the plasma membrane without the involvement of a transport protein?
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Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein?
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Passive transport permits the transported molecules to move in either direction, but the majority of transport occurs down the concentration gradient of the molecule.
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Diffusion is an active process.
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Which one of the following is not in some way involved in facilitated diffusion?
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Imagine two solutions separated by a selectively permeable membrane that allows water to pass, but not sucrose or glucose. The membrane separates a 0.2 molar sucrose solution from a 0.2 molar glucose solution. With time, how will the solution change?
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What is cotransport?
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What is the voltage across a cell membrane called?
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One of the functions of cholesterol in animal cell membranes is to?
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Which of the following is a difference between active transport and facilitated diffusion?
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Which one of the following pairs matches the name of a membrane transport process with the primary function of that process?
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Which of the following correctly states the relationship between anabolic and catabolic pathways?
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According to the second law of thermodynamics, the decrease in entropy associated with life must be compensated for by an increase in entropy in the environment that life occurs in.
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Metabolic pathways in cells are typically far from equilibrium. Which of the following processes tend to keep these pathways away from equilibrium?
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What is ATP?
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A chemical reaction is designated as exergonic rather than endergonic when?
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Enzymes speed up the rate of the reaction without changing the delta-G for the reaction.
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Enzymes generally slow reaction rates.
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Which of the following statements about the active site of an enzyme is correct?
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The process of stabilizing the structure of an enzyme in its active form by the binding of a molecule is an example of?
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Study Notes
Cell Organelles and Structures
- Mitochondria and chloroplasts share a double membrane structure, essential for their functions in energy production and photosynthesis.
- The extracellular matrix contains proteins and carbohydrates, plays a role in mechanical signaling, and attaches to the plasma membrane; however, it is not present in plant cells.
- Cytoskeleton provides structural support and aids in cellular motility, important for cell shape and movement.
Transport Mechanisms
- Passive transport encompasses diffusion, osmosis, and facilitated diffusion, allowing molecules to move without energy input, generally down their concentration gradients.
- Facilitated diffusion assists molecules, such as ions and larger solutes, via transport proteins and does not require external energy.
- Active transport requires energy, typically from ATP, to move substances against their concentration gradients.
- An example of passive diffusion is carbon dioxide, which can cross the plasma membrane freely due to its nonpolar nature, while polar molecules struggle without assistance.
- Membrane potential is the voltage across a cell membrane, influencing transport and communication.
Solutions and Osmosis
- In a selectively permeable membrane scenario, where sucrose and glucose solutions are separated, water will move toward the side with greater solute concentration after sucrose dissociates, altering the solution's balance.
Metabolism and Energy
- Anabolic pathways build complex organic molecules and rely on the energy produced from catabolic pathways, which break down these molecules.
- The second law of thermodynamics states that the entropy decrease in living systems must be compensated by increased entropy elsewhere.
- Metabolic pathways maintain non-equilibrium through the continuous removal of products and the intake of free energy from sources like food.
Enzymes and Reactions
- Enzymes function by speeding up reactions without altering the overall energy change (delta-G) of the process.
- The active site of an enzyme is a specific region where substrates bind, often resembling a groove or pocket configuration.
- Enzymes exhibit allosteric regulation, wherein molecule binding stabilizes their active form, enhancing catalytic activity.
- A reaction is characterized as exergonic if the products formed are less complex than the initial reactants.
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Description
Test your knowledge on key concepts in biology with these flashcards focused on cell structures and processes. Explore topics like mitochondria, chloroplasts, osmosis, and the cytoskeleton. Perfect for students looking to reinforce their understanding of cellular function.
