Mineral matter and organic matter together make up about 50 percent of soil. what two substances make up the other 50 percent?

The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Although a soil could be all sand, all clay, or all silt, that's rare. Instead most soils are a combination of the three.

The relative percentages of sand, silt, and clay are what give soil its texture. A loamy texture soil, for example, has nearly equal parts of sand, silt, and clay.

SOIL HAS STRUCTURE

Soil structure is the arrangement of soil particles into small clumps, called "peds". Much like the ingredients in cake batter bind together to form a cake, soil particles (sand, silt, clay, and organic matter) bind together to form peds. Peds have various shapes depending on their “ingredients” and the conditions under which the peds formed: getting wet and drying out, freezing and thawing--even people walking on or farming the soil affects the shapes of peds.

Ped shapes roughly resemble balls, blocks, columns, and plates. Between the peds are spaces, or pores, in which air, water, and organisms move. The sizes of the pores and their shapes vary from soil structure to soil structure.

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.