3 2.3 When an enzyme is present for a chemical reaction
1
U
1. The reaction requires less energy
II. No reactants are required
III. The enzyme can be used over and over again.
a. I only
b. I and II only
c. I and III only
d. II and III only
e. I, II, and III

b brown mice / white sand dunes

the cell is the smallest structural and functional unit of living organisms, which can exist on its own. therefore, it is sometimes called the building block of life. some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.

reflection is the bouncing back of a propagating wave when it encounters a barrier; usually shows an image of the source of light wave

1) bounces back from an opaque material

2) bounces back from the boundary

3) seen in mirrors

refraction is the bending of a propagating wave having a shift of direction as it passes through different media; usually seen in lenses to magnify or lessen

1) passes through a prism

2) moves from one medium to another

3) seen in lenses