How does a protein get into the mitochondria?

Proteins are translocated into the mitochondrial matrix space by passing through the TOM and TIM complexes at sites of adhesion between the outer and inner membranes known as contact sites.

What do porins do in the mitochondria?

Mitochondrial porins, or voltage-dependent anion-selective channels (VDAC) allow the passage of small molecules across the mitochondrial outer membrane, and are involved in complex interactions regulating organellar and cellular metabolism.

How do protein complexes in the inner membrane of mitochondria?

This membrane surrounds the mitochondrial matrix, where the citric acid cycle produces the electrons that travel from one protein complex to the next in the inner membrane. During electron transport, the participating protein complexes push protons from the matrix out to the intermembrane space.

Does protein synthesis occur in the mitochondria?

This means that the protein synthesis takes place in the cytoplasm, on top of the rough endoplasmic reticulum, in the mitochondria and on the mitochondrial membrane.

What are porins and their functions?

Porins are water-filled pores and channels found in the membranes of bacteria and eukaryotes. Porins are primarily involved in passively transporting hydrophilic molecules of various sizes and charges across the membrane. For survival, certain required nutrients and substrates must be transported into the cells.

Are there porins in mitochondria?

Mitochondrial outer membrane permeability is conferred by a family of porin proteins. Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals.

How is the inner membrane of the mitochondria adapted to its function?

The inner membrane folds over many times and creates layered structures called cristae. The folding of the inner membrane increases the surface area inside the organelle. Since many of the chemical reactions happen on the inner membrane, the increased surface area creates more space for reactions to occur.

How do protein complexes in the inner membrane of mitochondria play important role in cellular respiration?

Biological energy conversion in mitochondria is carried out by the membrane protein complexes of the respiratory chain and the mitochondrial ATP synthase in the inner membrane cristae. These are the products of ATP hydrolysis at the sites where energy is needed in the cell.

Where does the protein synthesis takes place?

Ribosomes
Ribosomes are the sites in a cell in which protein synthesis takes place.

Where are most mitochondria proteins made?

By far the majority of mitochondrial proteins, about 99\%, are made outside the mitochondria in the cellular cytoplasm. These proteins are then transported into the outer membrane, the inner membrane, the intermembrane space, or the matrix of the mitochondria.

How do proteins move from the outer membrane to the mitochondria?

These proteins are then shuttled to the mitochondrion through special cellular signals that match the proteins to the outer membrane surface. From the surface, the proteins interact with a protein called translocase, which sorts the proteins toward their final destination inside the mitochondrion.

What is the function of the general import pore in mitochondria?

This is actually a complex of proteins. It is called the General Import Pore (GIP) and it facilitates the translocation of the presequence of the protein across the outer membrane. (the GIP is made of Tom40, Tom5, Tom 6, and Tom7). Tom40 appears to be the core element of the pore and forms oligomers.

What is the function of mitochondria in large complexes?

Many mitochondrial proteins function as part of large complexes such as the oxidative phosphorylation machinery, proteins involved in RNA, DNA and protein synthesis, ion transport, and lipid metabolism.