What is the fluid-like substance found inside a mitochondrion?
A Matrix
B Cristae
C Reticulum
D Lysosome
The correct answer and explanation is:
The correct answer is A) Matrix.
The matrix is the fluid-like substance found inside the mitochondrion. It is the innermost compartment of the mitochondrion, located within the inner membrane, and is surrounded by the outer membrane. The matrix contains a variety of enzymes, proteins, and other molecules that are essential for the processes of cellular respiration, particularly the Krebs cycle (also known as the citric acid cycle or TCA cycle). This is where most of the metabolic reactions that produce energy in the form of ATP (adenosine triphosphate) take place.
The matrix is rich in enzymes that facilitate the breakdown of carbohydrates, fatty acids, and amino acids into energy. These processes involve the transfer of high-energy electrons and the production of NADH and FADH2, which then enter the electron transport chain located in the inner membrane of the mitochondrion. The energy released from these reactions is used to generate ATP through a process called oxidative phosphorylation.
In addition to enzymes, the matrix also contains mitochondrial DNA and ribosomes. The presence of mitochondrial DNA is one of the reasons why mitochondria are often described as semi-autonomous organelles. They can replicate independently of the cell and produce some of their own proteins, although they rely on the cell for many others.
The cristae (answer choice B) are the folds of the inner mitochondrial membrane, where the electron transport chain takes place, and the lysosome (answer choice D) is an organelle responsible for the breakdown of waste materials, so these are not correct answers. The reticulum is not a specific term used to describe any part of the mitochondrion.