What is Mitoplast?

Question

What is Mitoplast?

Accepted Answer

The correct option is 4: Mitochondrion without outer membrane.

To understand what a mitoplast is, let's first recall the structure of a mitochondrion. Mitochondria are double-membraned organelles, meaning they have an outer mitochondrial membrane (OMM) and an inner mitochondrial membrane (IMM). The space between these two membranes is called the intermembrane space, and the compartment enclosed by the inner membrane is the mitochondrial matrix. A mitoplast is specifically a mitochondrion from which the outer mitochondrial membrane has been removed, leaving the inner membrane, intermembrane space, and matrix intact. This preparation is crucial in biochemical studies to isolate and analyze the functions of the inner mitochondrial membrane and the components within the matrix without the interference of the outer membrane.

The incorrect option is 1: Membrane less mitochondria.
Mitochondria are characterized by their double membrane structure. A "membrane less mitochondria" would imply the complete absence of both inner and outer membranes, which is not what a mitoplast is. The inner membrane is a critical component of the mitoplast, housing the electron transport chain and ATP synthase.

The incorrect option is 2: Mitochondria without inner membrane.
If a mitochondrion were without its inner membrane, it would lose its functional core. The inner membrane is highly folded into cristae and is where the majority of ATP synthesis occurs. A mitoplast, however, retains its inner membrane, as its purpose is often to study the processes occurring at or within this crucial membrane.

The incorrect option is 3: Another name of mitochondria.
Mitoplast is not just another name for mitochondria. It refers to a specific, modified form of the mitochondrion where the outer membrane has been selectively removed. The term "mitochondria" refers to the complete organelle with both membranes intact.