Enzymes are catalysts which means that they A) speed up ...

[KimWrice]

Enzymes are catalysts which means that they
 
  A) speed up biochemical reactions which would normally occur too slowly
  B) slow down biochemical reactions which would normally occur too quickly
  C) prevent unwanted biochemical reaction occurring
  D) destroy harmful chemical species

Question 2

All of the following observations are real. Which one does not support the theory that active galactic nuclei are powered by accretion disks around massive black holes?
 
  A) X-ray emission from active galactic nuclei can vary significantly in times as short as a few days.
  B) The total luminosity of an active galactic nucleus can be as high as about 10 billion times that of the Sun.
  C) Spectra of active galactic nuclei show that clouds of gas are orbiting a central object at very high speed.
  D) The most luminous active galactic nuclei have huge redshifts.

[dmurph1496]

Answer to Question 1

A

Answer to Question 2

D

[KimWrice]

Excellent

[blakcmamba]

Gracias!