those are nucleotides
since all three of them contain deoxyribose (because there's only one hydroxil group) they are DNA nucleotides
the first nucleotide has cytosine as it's nitrogenous base
the second nucleotide has adenine as it's nitrogenous base
the third nucleotide has thymine as it's nitrogenous base
If denaturation occurs (extreme temperature change or pH changes), the enzyme will not be reusable! The structure of the enzymes are not changed. As a result of this, enzymes will be used again and again to bind onto another substrate molecule and catalyze the reaction once again.
C
Hot springs are heated by the geothermal heat- heat from the Earths interior.
C6H12O6+6O2->6CO2+6H2O+ATP
Homeostasis is maintained by negative feedback loops within the organism. In contrast, positive feedback loops push the organism further out of homeostasis, but may be necessary for life to occur. Homeostasis is controlled by the nervous and endocrine systems in mammals.