Topic 3A Part B Flashcards
Outer membrane:
The outer membrane is smooth and acts as a protective layer. It encloses the entire mitochondrion and separates it from the rest of the cell’s cytoplasm.
Inner membrane:
The inner membrane is highly folded, forming structures called cristae. These folds increase the surface area available for chemical reactions. The inner membrane is where the key processes of cellular respiration occur, including the production of ATP.
Matrix:
The space inside the inner membrane is called the matrix. The matrix contains enzymes, mitochondrial DNA, and ribosomes. The enzymes in the matrix are involved in the Krebs cycle (part of aerobic respiration), which helps produce energy for the cell.
Intermembrane space:
The area between the inner and outer membranes is known as the intermembrane space. This space is involved in some steps of cellular respiration, particularly in the generation of a proton gradient that is essential for ATP production.
Mitochondrial DNA:
Mitochondria have their own circular DNA, which is separate from the DNA found in the cell’s nucleus. This DNA is responsible for producing some of the proteins required by the mitochondria for energy production.
Ribosomes:
Mitochondria contain small ribosomes, similar to those found in prokaryotic cells. These ribosomes are involved in protein synthesis within the mitochondrion.
What are found in the matrix of the mitochondria?
Answer: Ribosomes and mitochondrial DNA.
What is the role of mitochondrial DNA in mitochondria?
Answer: Mitochondrial DNA is necessary for mitochondrial replication prior to cell division
Why are ribosomes found in the mitochondrial matrix important?
Answer: Ribosomes in the matrix are involved in protein synthesis within the mitochondria.
What is the shape of mitochondrial DNA?
Answer: Mitochondrial DNA is circular and is a tiny fragment of DNA.
Why are mitochondria called the ‘powerhouses’ of the cell?
Answer: Mitochondria are called the ‘powerhouses’ because they produce ATP, which is used to power the cell’s functions.
What process takes place in the mitochondria to produce ATP?
Answer: Cellular respiration, where simple molecules are oxidised to produce ATP.
What can the number of mitochondria in a cell tell you?
Answer: The number of mitochondria can indicate the energy demands of the cell. Cells with high energy requirements, like muscle and liver cells, have many mitochondria.
Do cells that require little energy have many or few mitochondria?
Answer: Cells that require little energy have very few mitochondria.
Give an example of cells with high energy demands that contain many mitochondria.
Answer: Muscle cells and liver cells are examples of cells with high energy demands and many mitochondria.
