Question

Would you expect the elemental composition of Earth's crust to be the same as that of the human body? How does high temperature affect protein structure? When an organism is exposed to high temperature, it often makes a special class of molecular chaperones called heat shock proteins. How do you think these proteins work?

Answer 1

1. The human body will be different from the earth's composition since life requires a different proportion of atoms, compared to the earth. The earth’s crust has numerous elements. Six elements account for 99% of the mass of the human body. The acronym CHNOPS may be used to help remember the six key chemical elements that are used in biological molecules. C is carbon, H is hydrogen, N is nitrogen, O is oxygen, P is phosphorus, and S is sulphur. Human body requires very less elements for the normal functioning. Thus, earth’s crust is not as same as human body.

2.

High temperatures can denature proteins and break the hydrogen bonds. When a cell is exposed to high temperatures, several types of molecular chaperones swing into action. For this reason, these chaperones are also called heat-shock proteins (HSPs).

Not only do molecular chaperones assist in the folding of newly-synthesized proteins, but some of them can also unfold aggregated proteins and then refold the protein properly. Protein aggregation is the cause of disorders such as Alzheimer's disease, Huntington's disease, and prion diseases. Perhaps someday ways will be found to treat these diseases by increasing the efficiency of disaggregating chaperones.

Despite the importance of chaperones, the final shape of a protein is determined by only one thing i.e. the precise sequence of amino acids in the protein.

And the sequence of amino acids in every protein is dictated by the sequence of nucleotides in the gene encoding that protein. So the function of each of the thousands of proteins in an organism is specified by one or more genes.