The process by which hydrophilic molecule move across the membrane by proteins is known as

Options

A. osmosis
B. facilitated diffusion
C. active transport
D. plasmolysis

Answer

To solve the question, we need to identify the correct process by which hydrophilic molecules move across the membrane with the help of proteins. Let's break down the options provided:

1. **Osmosis**: This process specifically refers to the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. It does not involve proteins for the movement of hydrophilic molecules other than water.

2. **Facilitated Diffusion**: This is a type of passive transport that allows hydrophilic molecules to cross the membrane with the help of specific proteins. The movement occurs along the concentration gradient, meaning that molecules move from an area of higher concentration to an area of lower concentration without the use of energy (ATP).

3. **Active Transport**: This process also involves proteins but requires energy (ATP) to move molecules against their concentration gradient (from lower concentration to higher concentration). Since the question does not mention the requirement of ATP, this option is not applicable.

4. **Plasmolysis**: This term refers to the process where cells lose water in a hypertonic solution, leading to the shrinkage of the cell. It does not describe the movement of molecules across the membrane.

Based on the analysis of these options, the correct answer is **Facilitated Diffusion**.

### Step-by-Step Solution:
1. **Identify the processes listed**: Osmosis, Facilitated Diffusion, Active Transport, Plasmolysis.
2. **Analyze Osmosis**: Understand that it specifically pertains to water movement, not hydrophilic molecules in general.
3. **Evaluate Facilitated Diffusion**: Recognize that this is a passive transport mechanism that requires proteins to assist hydrophilic molecules in crossing the membrane along their concentration gradient.
4. **Consider Active Transport**: Note that this process requires energy and moves substances against their concentration gradient, which is not indicated in the question.
5. **Understand Plasmolysis**: Realize that this term describes a cellular process related to water loss and does not pertain to the movement of molecules across the membrane.
6. **Conclude with the correct answer**: Based on the analysis, the process by which hydrophilic molecules move across the membrane by proteins is **Facilitated Diffusion**.