A fully folded 100-residue protein is only about 40 kJ ∙ mol−1 more stable than its unfolded form (for comparison, the energy required to break a typical hydrogen bond is ∼20 kJ ∙ mol−1).

TLS Online TPP Program

#Id: 7914

#XL - Q Biochemistry

Matrix-targeting sequences

Located at the N-terminus

Usually 20–50 amino acids in length

Rich in hydrophobic amino acids, positively charged basic amino acids (arginine & lysine), and hydroxylated ones (serine and threonine)

Amphipathicity of matrix-targeting sequences is critical to their function

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#Id: 7915

#XL - Q Biochemistry

Mitochondrial protein import requires: 

Tom proteins (Tom 20/22/70)

General import pore (Tom40)

Tim proteins (Tim23/17)

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#Id: 7916

#XL - Q Biochemistry

Energy inputs are needed to Import proteins into mitochondria

Chaperone proteins (Hsp70& Hsp90)

An H+ electrochemical gradient, or proton-motive force

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#Id: 7917

#XL - Q Biochemistry

Brown Adipose Tissue

is brown because of the presence of large numbers of mitochondria (high concentrations of cytochromes), with heme groups that are strong absorbers of visible 

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#Id: 7918

#XL - Q Biochemistry

TLS Online TPP Program

#Id: 7919

#XL - Q Biochemistry

The mitochondria of brown adipocytes have a unique protein in their inner membrane, Thermogenin (uncoupling protein 1 ), provides a path for protons to return to the matrix without passing through the FoF1 complex.