1. Fibrous proteins: These proteins have long, thin, and fiber-like structures. They are often strong and insoluble in water. Examples include collagen, keratin, and elastin.
2. Globular proteins: These proteins have a spherical or globular shape. They are usually soluble in water and have complex, folded structures. Examples include enzymes, antibodies, and hormones.
It's important to note that these are just two main categories, and there are many other ways to classify proteins, such as:
* Function: Proteins can be classified by their function, such as structural proteins, enzymes, hormones, etc.
* Composition: Proteins can be classified based on their amino acid composition, such as simple proteins and conjugated proteins.
So, while the two categories of fibrous and globular proteins are a good starting point, it's important to consider other ways to categorize proteins depending on the context.
