Question

an extensive system of internal membranes, called the _______, is where carbohydrates and lipids are manufactured and proteins are made that will be exported from the cell.

multiple choice

golgi complex

nucleolus

mitochondrion

endoplasmic reticulum

Explanation:

To solve this, we analyze each option:

• Golgi complex: Modifies, sorts, and packages proteins/lipids, not the site of their synthesis.
• Nucleolus: Involved in ribosome production, not in manufacturing carbs, lipids, or export - bound proteins.
• Mitochondrion: Produces ATP (energy), not involved in the synthesis of carbs, lipids, or export - bound proteins as described.
• Endoplasmic reticulum (ER): The rough ER is involved in protein synthesis (especially for export), and the smooth ER is involved in lipid and carbohydrate synthesis. The ER is an extensive internal membrane system that matches the description.

Answer:

D. endoplasmic reticulum