Conformational isomers are a type of isomer that differ only in the rotation around single bonds. This means that they have the same connectivity of atoms, but different spatial arrangements due to rotation. To recognize if an isomer is a conformational isomer, you can compare the different spatial arrangements of the molecule by rotating around single bonds and observing if the relative positions of the atoms change. If the only difference between the isomers is the rotation around single bonds, then they are conformational isomers. **

This isomer doesn't work because the arrangement of atoms in the molecule does not allow it to fit into the active site of the target enzyme or receptor. The specific spatial orientation of the functional groups in the isomer may prevent it from forming the necessary interactions with the binding site, leading to a lack of biological activity. Additionally, the isomer may not have the correct stereochemistry or conformation required for proper binding and activity. **

1-butene is a cis isomer. In the cis isomer, the two identical groups are on the same side of the double bond, while in the trans isomer, the two identical groups are on opposite sides of the double bond. In the case of 1-butene, the two methyl groups are on the same side of the double bond, making it a cis isomer. **

The isomer of C7H16 is heptane. Heptane is an alkane with a straight-chain structure, meaning it has seven carbon atoms in a row with 16 hydrogen atoms attached to them. It is a colorless, flammable liquid that is commonly used as a solvent in laboratories and as a component in gasoline. **

N-pentane is an isomer because it has the same molecular formula as other pentane isomers (C5H12) but a different structural arrangement of its carbon and hydrogen atoms. Isomers are compounds that have the same molecular formula but different structural formulas, leading to distinct chemical and physical properties. In the case of n-pentane, its straight-chain structure sets it apart from other pentane isomers like isopentane and neopentane, which have branched structures. **

There is no isomer of butane because butane is a straight-chain alkane with four carbon atoms, which means there is only one way for the carbon atoms to be arranged in a straight line. Isomers are molecules that have the same molecular formula but different structural arrangements of atoms. Since butane only has one possible arrangement of its carbon atoms in a straight chain, there are no other possible isomeric structures for butane. **

There is no isomer of propane because the carbon atoms in the propane molecule are arranged in a straight chain, with each carbon atom forming single bonds with the surrounding hydrogen atoms. This arrangement does not allow for any other structural isomers to form. Isomers are molecules with the same molecular formula but different structural arrangements of atoms. Since the carbon atoms in propane are already in a straight chain, there are no other possible structural arrangements that would result in a different molecule with the same molecular formula. **

A conformational isomer of glucose is a molecule that has the same chemical formula and sequence of bonded atoms as glucose, but differs in the spatial arrangement of its atoms due to rotation around single bonds. In the case of glucose, one example of a conformational isomer is the chair and boat forms of its cyclic structure. These isomers have different spatial arrangements of the hydroxyl groups and hydrogen atoms around the ring, resulting in different steric interactions and stability. **