The best answer is C - to break down food into nutrients.
The digestive system breaks down food into its simplest form that cell are able to utilize for energy. Food is broken down into its monomer units. Proteins are broken down into amino acids, lipids are broken down into fatty acids and glycerol and carbohydrates are broken down into glucose.
Glucose is then absorbed into the blood and transported to every cell in the body. The cells take in glucose and use it as fuel and raw material in the process of cellular respiration. From one molecule of glucose, 36 to 38 molecules of ATP ( the form of energy used by cells) are produced.
The answer is it provides us with vitamins. Hope this helps.
Answer:
The cell membrane is semi-permeable. It allows some molecules to enter easily inside the cell whereas some molecules are blocked from entering the cell.
Small, polar molecules and hydrophobic molecules enter easily through the cell membrane. But large molecules and ions cannot easily move inside the cell membrane.
A hydrophilic substance like the substance L mentioned in the question enters the cell membrane through the help of carrier proteins. The substance attached to the large protein might enter through active or passive diffusion but it can only enter the cell by attaching to carrier proteins.
