Nadine is writing a paper about amino acids. Choose the correct way to complete each sentence.

The body needs 20 amino acids to build __1. Half of these amino acids come from food that people eat. They are called _2_ amino acids. The human body produces the other half of the amino acids, which are called the _3___amino acids.

1. proteins, cells, cytoplasm
2. essential, nonessential
3. essential, nonessential

for #1 the body needs 20 amino acids to make/build a protein (Proteins are like the construction crew in your body. They transport substances, build others, and convert energy to help your body's mechanical processes. Amino acids are protein's building blocks. Your body needs 20 of them to help it function properly, as well as build and repair itself.)

for #2 there are 10 *essential* acids you can only get from your diet (Essential amino acids cannot be made by the body. As a result, they must come from food. The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.)

for #3 are *nonessential* In the human body, the liver produces about 80 percent of the amino acids needed. The remaining 20 percent must be obtained from the diet. These are called the Nonessential amino acids.