Similarity:
Both amoeba and human beings require nutrients for their survival and growth.

Difference:
There are several differences in the nutrition of amoeba and human beings.

1. Mode of Nutrition:
- Amoeba is a unicellular organism that exhibits holozoic nutrition. It engulfs its food by the process of phagocytosis and forms food vacuoles. The food is then digested inside these vacuoles.
- Human beings are multicellular organisms that exhibit heterotrophic nutrition. They consume complex organic molecules from outside sources and break them down into simpler forms through digestion.

2. Feeding Mechanism:
- Amoeba extends its pseudopodia (temporary finger-like projections) to surround and engulf its food. The food is then enclosed in a food vacuole, where digestion occurs.
- Human beings have a specialized digestive system with different organs and structures. The food is ingested through the mouth, chewed by teeth, mixed with saliva, and then swallowed. It passes through the esophagus, stomach, small intestine, and large intestine, where it is digested and absorbed.

3. Digestive Enzymes:
- Amoeba secretes digestive enzymes into its food vacuoles to break down complex molecules into simpler forms. These enzymes include proteases, lipases, and carbohydrases.
- Human beings have various digestive enzymes produced by different organs. For example, salivary amylase in the mouth breaks down carbohydrates, pepsin in the stomach digests proteins, and pancreatic lipase in the small intestine breaks down fats.

4. Process of Absorption:
- Amoeba directly absorbs the digested food molecules from its food vacuoles into its cytoplasm through the process of diffusion.
- Human beings have specialized structures for absorption, such as villi in the small intestine. The digested nutrients are absorbed through the villi into the bloodstream.

5. Excretion:
- Amoeba eliminates waste materials through a process called exocytosis. The undigested food and waste materials are expelled from the cell.
- Human beings excrete waste materials through the excretory system, primarily through the kidneys and urinary system.

In summary, while both amoeba and human beings require nutrients, their modes of nutrition, feeding mechanisms, digestive enzymes, absorption processes, and methods of excretion differ significantly.