The answer to this question would be: D)there are a few types of enzymes, but they each perform many types of reactions.
Enzyme is vital for a living since it will speed up the chemical reaction rate. This will help much in making and processing energy. But enzyme works like lock and key, which means that a specific enzyme will help specific reaction.
Answer:
The basic difference between SEM and TEM is that TEM generates an image with the assistance of radiation that goes through the specimen, while the images generated by the SEM take place with the assistance of electrons getting released from the surface of the specimen.
SEM is primarily used to examine the composition of the surface, with the help of SEM one can study the microbes present in the ecological niche like in the lining of the gut and human skin. Due to its great depth, it is considered the electron microscope analog of a stereo light microscope. It helps in providing complete images of the cells present on the surface, which are not easy to get with the help of TEM. Due to its enhanced functionality, it can also be used for size determination and particle counting, and also for process control.
1 kilometer = 6.68 × 
(<<<AU is in scientific notation here)
To convert 300 billion kilometer (3,000,000,000 km) into AU you must multiply the kilometer by the equivalent of 1 km in AU (6.68 × )
3,000,000,000 × (6.68 × ) = 20.04 AU
Hope this helped!
