What is a substrate?

a. a molecule that changes state
b. a place where the reaction occurs
c. a place on the product where the enzyme fits
d. a reactant that is catalyzed by an enzyme

B and D

Explanation:

In chemistry, a subtrate is said to be place or surface where chemical reaction takes place. But in biochemistry, a subtrate means a substance which an enzyme binds to, to catalyse its transformation into a slecific product or product. So a substrate has different meanings depending on the field of study.

the answer to your question is b

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation: