Did large predators keep humans out of north america

No humans fought back and live in America where they still hunted the animals

1. They make up cell structures such as cell membrane for example, where the lipids form a lipid bilayer.

2. They provide energy for the body. If the body does not have enough carbohydrates for energy, lipids are the next to break down.

3. They help protect the organs inside body. They act as a shock absorber and the prevent the organs being physically damaged.