Topic 3B: Membrane Structure and Function 3.6 Diffusion Complete ... - Free Printable

The task involves completing a diagram about membrane transport across the cell. Let's break it down step by step and fill in the missing information.

Diagram Overview

The diagram is divided into two main sections:
1. Passive Transport (left side)
2. Active Transport (right side)

Each section describes different types of transport mechanisms, their requirements, and examples.

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Passive Transport (Left Side)

#### 1. Phospholipid Bilayer
- The cell membrane is composed of a phospholipid bilayer, which forms the basic structure for transport.

#### 2. Transport Across the Cell Membrane
- Occur: Down the concentration gradient (high → low).
- Requires: No energy.
- Types of Passive Transport:
- Simple Diffusion:
- Example: Movement of water, CO₂, O₂, etc.
- Explanation: Molecules move from an area of high concentration to an area of low concentration until equilibrium is reached.
- Facilitated Diffusion:
- Example: Transport of glucose or ions like Na⁺, K⁺, etc.
- Explanation: Requires help from carrier proteins or channel proteins to assist in the movement of molecules across the membrane.

#### 3. Osmosis
- Definition: Movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.
- Result: Water moves until equilibrium is reached.

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Active Transport (Right Side)

#### 1. Transport Across the Cell Membrane
- Occur: Against the concentration gradient (low → high).
- Requires: Energy (ATP).

#### 2. Types of Active Transport
- Primary Active Transport:
- Example: Sodium-potassium pump (Na⁺/K⁺ pump).
- Explanation: Uses ATP directly to move ions against their concentration gradient.
- Secondary Active Transport:
- Example: Symporters and Antiporters.
- Explanation: Uses the electrochemical gradient created by primary active transport to move other substances.
- Bulk Transport:
- Endocytosis:
- Example: Phagocytosis (cell eating), Pinocytosis (cell drinking).
- Explanation: Large particles or fluids are taken into the cell by engulfing them with the cell membrane.
- Exocytosis:
- Example: Secretion of hormones, enzymes, etc.
- Explanation: Materials are expelled from the cell by fusing vesicles with the plasma membrane.

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Completed Diagram

Here is the completed version of the diagram:

#### Passive Transport (Left Side)
- Phospholipid Bilayer
- Transport Across the Cell Membrane
- Occurs: Down the concentration gradient (High → Low)
- Requires: No energy
- Simple Diffusion
- Example: Water, CO₂, O₂
- Explanation: Molecules move from high concentration to low concentration until equilibrium is reached.
- Facilitated Diffusion
- Example: Glucose, ions (e.g., Na⁺, K⁺)
- Explanation: Requires help from carrier proteins or channel proteins.

#### Active Transport (Right Side)
- Transport Across the Cell Membrane
- Occurs: Against the concentration gradient (Low → High)
- Requires: Energy (ATP)
- Primary Active Transport
- Example: Sodium-potassium pump (Na⁺/K⁺ pump)
- Explanation: Uses ATP directly to move ions against their concentration gradient.
- Secondary Active Transport
- Example: Symporters, Antiporters
- Explanation: Uses the electrochemical gradient created by primary active transport to move other substances.
- Bulk Transport
- Endocytosis
- Example: Phagocytosis, Pinocytosis
- Explanation: Large particles or fluids are taken into the cell by engulfing them with the cell membrane.
- Exocytosis
- Example: Secretion of hormones, enzymes
- Explanation: Materials are expelled from the cell by fusing vesicles with the plasma membrane.

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Final Answer

The completed diagram is as follows:

\[
\boxed{
\begin{array}{|c|c|}
\hline
\textbf{Passive Transport} & \textbf{Active Transport} \\
\hline
\text{Phospholipid Bilayer} & \text{Transport Across the Cell Membrane} \\
\text{Occurs: Down the concentration gradient (High → Low)} & \text{Occurs: Against the concentration gradient (Low → High)} \\
\text{Requires: No energy} & \text{Requires: Energy (ATP)} \\
\hline
\text{Simple Diffusion} & \text{Primary Active Transport} \\
\text{Example: Water, CO₂, O₂} & \text{Example: Sodium-potassium pump (Na⁺/K⁺ pump)} \\
\text{Explanation: Molecules move from high concentration to low concentration until equilibrium is reached.} & \text{Explanation: Uses ATP directly to move ions against their concentration gradient.} \\
\hline
\text{Facilitated Diffusion} & \text{Secondary Active Transport} \\
\text{Example: Glucose, ions (e.g., Na⁺, K⁺)} & \text{Example: Symporters, Antiporters} \\
\text{Explanation: Requires help from carrier proteins or channel proteins.} & \text{Explanation: Uses the electrochemical gradient created by primary active transport to move other substances.} \\
\hline
\text{Osmosis} & \text{Bulk Transport} \\
\text{Water moves until equilibrium is reached.} & \text{Endocytosis: Phagocytosis, Pinocytosis} \\
& \text{Exocytosis: Secretion of hormones, enzymes} \\
\hline
\end{array}
}
\]