B.2 Fibrous and globular proteins (SL)

Summary

This video explores the differences between fibrous and globular proteins. Fibrous proteins, such as collagen, are elongated molecules with dominant secondary structures, insoluble in water, and provide structural support. In contrast, globular proteins, like hemoglobin, are spherical, water-soluble, and play roles in catalysis and transport. The video compares their shapes, roles, solubility, amino acid sequences, and stability, highlighting fibrous proteins as strong and less sensitive to environmental changes, while globular proteins are more sensitive but have diverse functions.

Takeaways

• 🧬 Fibrous proteins are elongated molecules with dominant secondary structures such as alpha helices or beta sheets.
• 💧 Fibrous proteins are insoluble in water and form structural components in the body.
• 🧵 Collagen is an example of a fibrous protein.
• ⚪ Globular proteins are spherical molecules that are soluble in water and have tertiary, and sometimes quaternary, structures.
• 🩸 Hemoglobin is an example of a globular protein.
• 🔄 Fibrous proteins have a long, narrow shape, while globular proteins are rounded or spherical.
• 💪 Fibrous proteins provide strength and support, whereas globular proteins act as catalysts and aid in transport.
• 🌊 Fibrous proteins are mostly insoluble in water, while globular proteins are mostly soluble.
• 🔬 Fibrous proteins have a repetitive amino acid sequence, while globular proteins have an irregular sequence.
• 🔥 Fibrous proteins are less sensitive to changes in heat and pH, whereas globular proteins are more sensitive.

Q & A

What are fibrous proteins?

Fibrous proteins are elongated molecules where the secondary structure, such as the alpha helix or beta-pleated sheets, dominates. They are insoluble in water and primarily serve structural functions in the body.

Can you give an example of a fibrous protein?

An example of a fibrous protein is collagen.

What are globular proteins?

Globular proteins are spherical molecules that are soluble in water. They usually have a tertiary structure, and some have quaternary structures as well.

Can you provide an example of a globular protein?

Hemoglobin is an example of a globular protein.

How do fibrous and globular proteins differ in shape?

Fibrous proteins are long and narrow, while globular proteins are rounded or spherical.

What is the primary function of fibrous proteins?

Fibrous proteins are primarily used for strength and support in the body.

What roles do globular proteins serve?

Globular proteins function as catalysts and are involved in transport within the body.

Are fibrous proteins soluble in water?

No, fibrous proteins are mostly insoluble in water.

Are globular proteins sensitive to changes in heat and pH?

Yes, globular proteins are more sensitive to changes in heat and pH compared to fibrous proteins.

What are some other examples of fibrous and globular proteins?

In addition to collagen, keratin is an example of a fibrous protein. Other examples of globular proteins include insulin and catalase.