An element is...

• any substance that cannot be broken down into simpler substances.

• made up of only one kind of atom.

• a really good source of protein.

• listed by atomic symbol, element name and atomic number in the Periodic Table of Elements.

What 2 elements make up 99% of the air we breathe?

Carbohydrates are

• made of carbon, hydrogen and oxygen.

• energy-rich organic compounds.

• found in cell walls and cell membranes.

• sugars and starches.

Proteins are

• made of carbon, hydrogen, oxygen, nitrogen and sometimes sulfur.

• made up of smaller molecules called amino acids.

• meat, fish, eggs, and nuts.

• oils, fats and waxes.

Nucleic Acids

• are made of carbon, oxygen, hydrogen, nitrogen and phosphorus.

• contain the instructions that cells need to carry out all the functions of life.

• are found in the nucleus of a cell.

• taste bitter.