What three major food molecules are recognized by scientists

i. In chemical digestion, enzymes break down food into the small molecules the body can use. It is important to break down macromolecules into smaller fragments that are of suitable size for absorption across cell membranes.

ii. A fat molecule, such as a triglyceride, consists of two main components—glycerol and fatty acids. Glycerol is an organic compound with three carbon atoms, five hydrogen atoms, and three hydroxyl (–OH) groups.

iii. If it's in the table, it's an element! Atoms can join together - they form bonds together - to make MOLECULES. For example, two atoms of hydrogen hook together to form a molecule of hydrogen, H2 for short.

IV. When atoms join together to form molecules, they are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons between the atoms. ... Different atoms use these electrons to form one of three different types of bond: ionic bonds, covalent bonds, or metallic bonds.

v. Beginning with energy sources obtained from their environment in the form of sunlight and organic food molecules, eukaryotic cells make energy-rich molecules like ATP and NADH via energy pathways including photosynthesis, glycolysis, the citric acid cycle, and oxidative phosphorylation.