Questions and Answers
What type of molecules can pass through the cell membrane quickly?
Why does the cell membrane allow small molecules to pass through?
What is the main reason why glucose cannot pass through the cell membrane?
What is the property of the cell membrane that determines what enters and leaves?
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What is the main component of the cell membrane?
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Why did scientists stop using benzene to wash their hands?
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What is the reason why charged molecules cannot pass through the cell membrane?
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What is the main function of the cell membrane?
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What is the term for the property of the cell membrane that allows some substances to pass through while others cannot?
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What type of molecules are preferred by the cell membrane?
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What is the main building block of the cell membrane?
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What is the function of the glycerol backbone in a phospholipid?
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What is the purpose of the phosphate head group in a phospholipid?
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What are the two fatty acid tails in a phospholipid?
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What is the result of the cell membrane being semi-permeable?
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Why is the cell membrane important for our survival?
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What is the term for a molecule that has both hydrophobic and hydrophilic sections?
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What is the primary reason why the fatty acid tails in a phospholipid bilayer want to stay away from water?
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What is the shape of the cell membrane in a real-life cell?
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What is the term for the movement of small, nonpolar molecules through the cell membrane?
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What is an example of a small nonpolar molecule that can pass through the cell membrane?
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What is the term for the cell membrane's ability to control what enters and leaves the cell?
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What is the purpose of the phosphate head groups in a phospholipid bilayer?
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What is the shape of the phospholipid bilayer?
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What is the main reason why the cell membrane is able to form a bilayer structure?
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What is the function of the cell membrane in relation to the inside and outside of the cell?
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Study Notes
Cell Membrane Structure and Function
- The cell membrane is a crucial structure that prevents cells from filling up with water or leaking substances into the environment.
- It is semi-permeable, allowing certain substances to enter or leave the cell.
Phospholipids: Building Blocks of the Cell Membrane
- Phospholipids are the main components of the cell membrane.
- They have three main components: phosphate head group, glycerol backbone, and two fatty acid tails.
- The phosphate head group is hydrophilic (water-loving), while the fatty acid tails are hydrophobic (water-fearing).
- This creates an amphipathic molecule with both hydrophilic and hydrophobic regions.
Phospholipid Bilayer Formation
- When phospholipids are placed in water, the hydrophilic phosphate head groups cluster together, while the hydrophobic fatty acid tails face inward.
- This forms a unique structure called a phospholipid bilayer or lipid bilayer.
Cell Membrane Structure in Real-Life Cells
- In real cells, the phospholipid bilayer forms a sphere that surrounds the cell.
- The hydrophilic phosphate head groups face outward, interacting with water, while the hydrophobic fatty acid tails face inward.
Semi-Permeability of the Cell Membrane
- The cell membrane is semi-permeable, allowing small, nonpolar molecules to pass through.
- Examples of small, nonpolar molecules that can pass through the cell membrane include gases like O2 and CO2.
- Small, polar molecules like water and ethanol can also pass through, but at a slower rate.
- Large, nonpolar molecules like benzene can pass through, but slowly.
- Large, polar molecules like glucose and charged molecules like ions and amino acids cannot pass through the cell membrane.
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Description
Learn about the importance of cell membranes in preventing water and substance leakage from cells. Discover how this outer layer of a cell works and its significance.
