To understand which organelles are involved in synthesizing membrane-embedded proteins and delivering them to the cell membrane, let’s break down the options:
A) Endoplasmic Reticulum (ER): The endoplasmic reticulum plays a crucial role in the synthesis of proteins, including those that are embedded in the membrane. The rough ER, in particular, is studded with ribosomes and synthesizes proteins that are either secreted from the cell or incorporated into the cell’s membranes.
B) Ribosomes: Ribosomes are the cellular machinery responsible for protein synthesis. They translate mRNA into amino acid chains, forming proteins. While ribosomes synthesize proteins, the actual processing and delivery of membrane proteins primarily involve the ER. Thus, ribosomes contribute to the initial synthesis but are not directly involved in the delivery.
C) Contractile Vacuole: The contractile vacuole is primarily involved in regulating water balance within certain protists and does not participate in the synthesis or delivery of membrane-embedded proteins. Its function is different and unrelated to protein synthesis.
In conclusion, the correct answers are A) Endoplasmic Reticulum and B) Ribosomes. The ER is responsible for delivering the synthesized proteins to the cell membrane, while ribosomes are essential for protein synthesis.