Question

T/F

1. Specific sequences in the mRNA directly effect the sorting of proteins into various organelles in the cell. T/F?

2. All mitochondria proteins are coded for & synthesized in mitochondrial matrix. T/F?

3. All protein folding occurs spontaneously without the need of energy. T/F?

Answer 1

1. Specific sequences in the mRNA directly effect the sorting of proteins into various organelles in the cell. : True

The mRNA has specific nucleotide sequences. Three consecutive nucleotides called as a codon or gene and this codon is responsible for the secretion of a specific amino acids. The amino acids are joined together by peptide bonds and form a protein. Hence, when the sequence of mRNA changes, the amino acid synthesized is also changes and hence the protein. So, change in the specific sequence in the mRNA directly effect the sorting of proteins into various organelles by secreting different proteins.

2. All mitochondria proteins are coded for & synthesized in mitochondrial matrix. : False

Although many proteins are required for the mitochondrial activity (about 3000), only few proteins are secreted by the mitochondrial DNA. Most of the proteins are synthesized by the ribosomes in the cytoplasmic matrix of the cell and are transported to the mitochondrial matrix. About 3000 proteins used in mitochondrial functioning, only 13 are synthesized in the mitochondria.

3. All protein folding occurs spontaneously without the need of energy. : False

Protein folding means, proteins are folded to their three dimensional structures. The protein foldings are spontaneous process and hence uses negative value of Gibbs free energy. The Gibbs free energy is directly related to enthalpy and entropy and hence the protein folding requires energy and hence can't takes place in the absence of energy.