A key feature of enzymes is that they . a. interact generally within cells

b. are changed by reactions

c. are carbohydrates

d. are not used up in reactions

e. force reactions to occur

d. Are not used up in reactions

Explanation:

This is a property of enzymes. They are not used up since they don't participate in reactions. They just help increase the rate at which it occurs

1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.