What sphere refers to water and ice? a. atmosphere
b. hydrosphere
c. lithosphere
d. biosphere

Earth's outermost sphere is called the
a. biosphere.
b. atmosphere.
c. lithosphere.
d. hydrosphere.

What part of Earth contains rocks?
a. Biosphere
b. Hydrosphere
c. Atmosphere
d. Lithosphere

What of Earth's spheres is composed of a mixture of gases?
a. mesosphere
b. hydrosphere
c. atmosphere
d. biosphere

What is Earth's hydrosphere?
a. the gases in the air
b. the solid, rocky part of Earth
c. all of the water on the planet
d. the study of Earth's atmosphere​

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.