Cell Membrane Control - Middle School Life Science
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Identify the transport type: oxygen moves into a cell from higher outside concentration to lower inside concentration.
Identify the transport type: oxygen moves into a cell from higher outside concentration to lower inside concentration.
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Simple diffusion (passive transport). Small gas molecules diffuse freely without proteins or energy.
Simple diffusion (passive transport). Small gas molecules diffuse freely without proteins or energy.
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What is a carrier protein, in terms of membrane transport function?
What is a carrier protein, in terms of membrane transport function?
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A protein that binds a substance and changes shape to move it. Undergoes conformational change to transport molecules.
A protein that binds a substance and changes shape to move it. Undergoes conformational change to transport molecules.
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What is a channel protein, in terms of membrane transport function?
What is a channel protein, in terms of membrane transport function?
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A protein pore that lets specific ions or water pass. Forms tunnel for passive movement of specific molecules.
A protein pore that lets specific ions or water pass. Forms tunnel for passive movement of specific molecules.
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Which cellular molecule usually provides the energy for active transport?
Which cellular molecule usually provides the energy for active transport?
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ATP. Cell's energy currency powers uphill molecular transport.
ATP. Cell's energy currency powers uphill molecular transport.
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What type of transport moves substances from low to high concentration and requires energy?
What type of transport moves substances from low to high concentration and requires energy?
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Active transport. Uses energy to pump molecules against concentration gradient.
Active transport. Uses energy to pump molecules against concentration gradient.
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Which direction does water move by osmosis relative to solute concentration?
Which direction does water move by osmosis relative to solute concentration?
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Toward the side with higher solute concentration. Water dilutes concentrated solutions to reach equilibrium.
Toward the side with higher solute concentration. Water dilutes concentrated solutions to reach equilibrium.
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What is the basic structure of the cell membrane that forms a barrier?
What is the basic structure of the cell membrane that forms a barrier?
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Phospholipid bilayer. Two layers of phospholipids create the membrane's foundation.
Phospholipid bilayer. Two layers of phospholipids create the membrane's foundation.
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What is the main structural model that explains cell membrane organization?
What is the main structural model that explains cell membrane organization?
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Fluid mosaic model. Describes membrane as flexible with proteins embedded in lipids.
Fluid mosaic model. Describes membrane as flexible with proteins embedded in lipids.
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What property of the cell membrane describes allowing some substances through but not others?
What property of the cell membrane describes allowing some substances through but not others?
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Selective permeability (semipermeable). Allows only certain molecules through while blocking others.
Selective permeability (semipermeable). Allows only certain molecules through while blocking others.
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Which molecule provides energy for many active transport processes?
Which molecule provides energy for many active transport processes?
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ATP. The cell's energy currency powers transport pumps.
ATP. The cell's energy currency powers transport pumps.
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What is diffusion across a membrane called when it requires no energy from the cell?
What is diffusion across a membrane called when it requires no energy from the cell?
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Passive transport. Molecules move naturally down their concentration gradient.
Passive transport. Molecules move naturally down their concentration gradient.
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What is active transport?
What is active transport?
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Movement against the gradient using energy (ATP). Pumps molecules from low to high concentration areas.
Movement against the gradient using energy (ATP). Pumps molecules from low to high concentration areas.
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What is endocytosis?
What is endocytosis?
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Cell takes in substances by forming membrane vesicles. Membrane pinches inward to engulf external materials.
Cell takes in substances by forming membrane vesicles. Membrane pinches inward to engulf external materials.
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Identify the transport type: a white blood cell engulfs a bacterium into a vesicle.
Identify the transport type: a white blood cell engulfs a bacterium into a vesicle.
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Endocytosis (phagocytosis). Cell eating - membrane surrounds and engulfs large particles.
Endocytosis (phagocytosis). Cell eating - membrane surrounds and engulfs large particles.
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Identify the transport type: a cell uses ATP to pump $ ext{Na}^+$ out where $ ext{Na}^+$ is already higher outside.
Identify the transport type: a cell uses ATP to pump $ ext{Na}^+$ out where $ ext{Na}^+$ is already higher outside.
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Active transport. Energy required to pump ions against concentration gradient.
Active transport. Energy required to pump ions against concentration gradient.
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Identify the transport type: glucose crosses the membrane through a specific protein with no ATP used.
Identify the transport type: glucose crosses the membrane through a specific protein with no ATP used.
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Facilitated diffusion. Protein channels help polar molecules move down gradient.
Facilitated diffusion. Protein channels help polar molecules move down gradient.
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Which part of a phospholipid faces water: the head or the tails?
Which part of a phospholipid faces water: the head or the tails?
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The hydrophilic head faces water. Polar heads are attracted to water molecules.
The hydrophilic head faces water. Polar heads are attracted to water molecules.
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Which part of a phospholipid avoids water: the head or the tails?
Which part of a phospholipid avoids water: the head or the tails?
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The hydrophobic fatty acid tails avoid water. Nonpolar tails repel water, forming the membrane's interior.
The hydrophobic fatty acid tails avoid water. Nonpolar tails repel water, forming the membrane's interior.
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Identify the transport type: oxygen moves directly through the bilayer from high to low concentration.
Identify the transport type: oxygen moves directly through the bilayer from high to low concentration.
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Simple diffusion (passive transport). Small, nonpolar molecules cross the lipid bilayer freely.
Simple diffusion (passive transport). Small, nonpolar molecules cross the lipid bilayer freely.
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What is exocytosis?
What is exocytosis?
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Cell releases substances when vesicles fuse with the membrane. Vesicles merge with membrane to expel contents outside.
Cell releases substances when vesicles fuse with the membrane. Vesicles merge with membrane to expel contents outside.
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What phrase describes the cell membrane property of allowing some substances through but not others?
What phrase describes the cell membrane property of allowing some substances through but not others?
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Selectively permeable (semipermeable). Like a filter that blocks some molecules while letting others pass.
Selectively permeable (semipermeable). Like a filter that blocks some molecules while letting others pass.
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What type of membrane protein provides a passageway for specific ions or molecules?
What type of membrane protein provides a passageway for specific ions or molecules?
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Channel protein. Acts like a tunnel for specific ions or small molecules.
Channel protein. Acts like a tunnel for specific ions or small molecules.
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What type of membrane protein changes shape to move a substance across the membrane?
What type of membrane protein changes shape to move a substance across the membrane?
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Carrier protein. Binds and releases molecules through conformational changes.
Carrier protein. Binds and releases molecules through conformational changes.
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What is the main function of the cell membrane in controlling cell contents?
What is the main function of the cell membrane in controlling cell contents?
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It selectively regulates what enters and leaves the cell. Acts as a gatekeeper, maintaining cell homeostasis.
It selectively regulates what enters and leaves the cell. Acts as a gatekeeper, maintaining cell homeostasis.
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Which option describes facilitated diffusion: movement with or against the gradient?
Which option describes facilitated diffusion: movement with or against the gradient?
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With the gradient (high to low) using a membrane protein. Proteins help large or polar molecules cross without energy.
With the gradient (high to low) using a membrane protein. Proteins help large or polar molecules cross without energy.
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