Question

match the cell membrane structure or its function with the correct letter from the cell membrane diagram.
letter structure/function letter structure/function
__ attracts water __ repels water
__ helps maintain flexibility of membrane __ make up the bilayer
__ involved in cell - to - cell recognition __ help transport certain materials across the cell membrane
osmosis and tonicity
define osmosis. ____
in which direction does water move across membranes, up or down the concentration gradient? ____
define these 3 terms:
a. isotonic - ____
b. hypertonic ____

Explanation:

Part 1: Cell Membrane Structure-Function Matching (Assuming Standard Cell Membrane Diagram Labels: Typically, cell membrane diagrams have: A - Phospholipid bilayer, B - Maybe a protein channel, C - Cholesterol, E - Glycoprotein (cell recognition), F - Glycolipid, G - Phospholipid head (hydrophilic), I - Phospholipid tail (hydrophobic))

1. Attracts water

Phospholipid heads are hydrophilic (attract water). If G is the phospholipid head, then G (or the label for hydrophilic part) → Attracts water.

2. Helps maintain flexibility of membrane

Cholesterol (often labeled C) helps with membrane fluidity/flexibility → C → Helps maintain flexibility of membrane.

3. Involved in cell - to - cell recognition

Glycoproteins (labeled E, with carbohydrate chains) are for cell recognition → E → Involved in cell - to - cell recognition.

4. Repels water

Phospholipid tails are hydrophobic (repel water). If I is the phospholipid tail, then I → Repels water.

5. Make up the bilayer

Phospholipids (the bilayer is made of phospholipid molecules, with heads and tails; the bilayer structure is often labeled A) → A → Make up the bilayer.

6. Help transport certain materials across the cell membrane

Transport proteins (like channel or carrier proteins, maybe labeled B or F) → If B is a protein channel, B → Help transport certain materials across the cell membrane.

Part 2: Osmosis and Tonicity

Define osmosis

Osmosis is the passive transport (diffusion) of water molecules across a selectively permeable membrane from a region of higher water concentration (lower solute concentration) to a region of lower water concentration (higher solute concentration), driven by the concentration gradient of water.

Direction of water movement across membranes (concentration gradient)

Water moves down the concentration gradient (from an area of higher water potential/higher water concentration to an area of lower water potential/lower water concentration). In terms of solute concentration, it moves from a solution with lower solute concentration to a solution with higher solute concentration.

Define the terms:

• a. Isotonic: A solution with the same solute concentration as the solution (or cell cytoplasm) it is compared to. When a cell is in an isotonic solution, there is no net movement of water across the cell membrane (water moves in and out at equal rates).
• b. Hypertonic: A solution with a higher solute concentration than the solution (or cell cytoplasm) it is compared to. When a cell is in a hypertonic solution, water moves out of the cell (toward the hypertonic solution) because the water concentration inside the cell is higher than outside.

Final Answers (Matching Section - Typical Labels):

• Attracts water: G
• Helps maintain flexibility: C
• Cell - to - cell recognition: E
• Repels water: I
• Make up the bilayer: A
• Transport materials: B

(Note: Labels may vary slightly based on the specific diagram, but the above follows standard cell membrane structure conventions.)

• Osmosis definition: Passive diffusion of water across a selectively permeable membrane from high to low water concentration.
• Water movement direction: Down the concentration gradient (from high to low water concentration).
• Isotonic: Same solute concentration as the comparison solution.
• Hypertonic: Higher solute concentration than the comparison solution.

Answer:

Part 1: Cell Membrane Structure-Function Matching (Assuming Standard Cell Membrane Diagram Labels: Typically, cell membrane diagrams have: A - Phospholipid bilayer, B - Maybe a protein channel, C - Cholesterol, E - Glycoprotein (cell recognition), F - Glycolipid, G - Phospholipid head (hydrophilic), I - Phospholipid tail (hydrophobic))

1. Attracts water

Phospholipid heads are hydrophilic (attract water). If G is the phospholipid head, then G (or the label for hydrophilic part) → Attracts water.

2. Helps maintain flexibility of membrane

Cholesterol (often labeled C) helps with membrane fluidity/flexibility → C → Helps maintain flexibility of membrane.

3. Involved in cell - to - cell recognition

Glycoproteins (labeled E, with carbohydrate chains) are for cell recognition → E → Involved in cell - to - cell recognition.

4. Repels water

Phospholipid tails are hydrophobic (repel water). If I is the phospholipid tail, then I → Repels water.

5. Make up the bilayer

Phospholipids (the bilayer is made of phospholipid molecules, with heads and tails; the bilayer structure is often labeled A) → A → Make up the bilayer.

6. Help transport certain materials across the cell membrane

Transport proteins (like channel or carrier proteins, maybe labeled B or F) → If B is a protein channel, B → Help transport certain materials across the cell membrane.

Part 2: Osmosis and Tonicity

Define osmosis

Osmosis is the passive transport (diffusion) of water molecules across a selectively permeable membrane from a region of higher water concentration (lower solute concentration) to a region of lower water concentration (higher solute concentration), driven by the concentration gradient of water.

Direction of water movement across membranes (concentration gradient)

Water moves down the concentration gradient (from an area of higher water potential/higher water concentration to an area of lower water potential/lower water concentration). In terms of solute concentration, it moves from a solution with lower solute concentration to a solution with higher solute concentration.

Define the terms:

• a. Isotonic: A solution with the same solute concentration as the solution (or cell cytoplasm) it is compared to. When a cell is in an isotonic solution, there is no net movement of water across the cell membrane (water moves in and out at equal rates).
• b. Hypertonic: A solution with a higher solute concentration than the solution (or cell cytoplasm) it is compared to. When a cell is in a hypertonic solution, water moves out of the cell (toward the hypertonic solution) because the water concentration inside the cell is higher than outside.

Final Answers (Matching Section - Typical Labels):

• Attracts water: G
• Helps maintain flexibility: C
• Cell - to - cell recognition: E
• Repels water: I
• Make up the bilayer: A
• Transport materials: B

(Note: Labels may vary slightly based on the specific diagram, but the above follows standard cell membrane structure conventions.)

• Osmosis definition: Passive diffusion of water across a selectively permeable membrane from high to low water concentration.
• Water movement direction: Down the concentration gradient (from high to low water concentration).
• Isotonic: Same solute concentration as the comparison solution.
• Hypertonic: Higher solute concentration than the comparison solution.