Cells that line your intestines are known to possess a large number of membrane proteins that transport small molecules and ions across the plasma membrane. Which of the following cell structures would you expect to be required for this characteristic of the cells? a. the endoplasmic reticulum b. peroxisomes c. lysosomes d. the cell wall

Verified step by step guidance

1. Step 1: Understand the question. The question is asking which cell structure is necessary for the transport of small molecules and ions across the plasma membrane, a characteristic of the cells that line your intestines.
2. Step 2: Recall the functions of the given cell structures. The endoplasmic reticulum is involved in protein and lipid synthesis, peroxisomes break down fatty acids and amino acids, lysosomes digest unwanted materials in the cell, and the cell wall provides support and protection for the cell.
3. Step 3: Consider the function of the cell structure in relation to the characteristic of the cells. The transport of small molecules and ions across the plasma membrane is a process that involves proteins, which are synthesized in the endoplasmic reticulum.
4. Step 4: Eliminate the cell structures that are not related to this process. Peroxisomes, lysosomes, and the cell wall are not directly involved in the synthesis of proteins, hence they are not required for this characteristic of the cells.
5. Step 5: Choose the correct answer. Therefore, the endoplasmic reticulum (option a) is the cell structure that is required for this characteristic of the cells.

Key Concepts

Membrane Proteins

Membrane proteins are integral or peripheral proteins that reside within or on the surface of the cell membrane. They play crucial roles in transporting molecules and ions across the plasma membrane, facilitating communication and signaling between the cell and its environment. In intestinal cells, these proteins are essential for nutrient absorption and maintaining homeostasis.

Endoplasmic Reticulum (ER)

The endoplasmic reticulum (ER) is a network of membranes involved in the synthesis and transport of proteins and lipids. The rough ER, studded with ribosomes, is particularly important for producing membrane proteins, including those that transport molecules across the plasma membrane. Thus, the ER is vital for the functionality of intestinal cells that require extensive membrane protein activity.

Cell Membrane Structure

The cell membrane, composed of a phospholipid bilayer with embedded proteins, serves as a selective barrier that regulates the entry and exit of substances. Its structure allows for the dynamic arrangement of proteins that facilitate transport processes. Understanding the cell membrane's architecture is essential for grasping how intestinal cells manage the absorption of nutrients and ions.