When an enzyme is involved in a catabolic reaction a. its active site binds the substrates and changes shape, stressing the bond, lowering the activation energy, and breaking the bond. b. its active site binds the substrates and changes shape, bringing them close together, lowering the activation energy, and creating a bond. c. its active site binds the substrates and changes shape, stressing the bond, increasing the activation energy, and breaking the bond. d. its active site binds the substrates and changes shape, creating a bond by increasing the activation energy. e. none of the above.

Option-A

Explanation:

Enzymes are the protein molecules which speed up the chemical reaction in the organism and thus are known as the biocatalyst.

The enzymes are the tertiary structure of the proteins that is they are the globular form of the proteins. The globular structure contains an active site which is a pore-like structure to which the substrate molecules bind by forming a weak bond. This state is known as the transition stage which is higher in energy.

The formation of this transition state or enzyme-substrate complex lowers the threshold energy of reaction called activation energy and thus speed the reaction.

In the given question since the catabolic reaction involves the breaking of the bonds of the large molecules therefore the enzymes facilitate the breaking of the bond.

Thus, Option-A is the correct answer.

the answer will be a) proteins i believe

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.