Collagen

• Collagen has 4 polypeptide chains wound around eachother
• The polypeptide chains are coils, held together by hydrogen bonds
• Form collagen fibrils. Many collagen fibrils together form collagen fibres
• Collagen is so strong as glycine is small and this allows close packing between the molecules
• It also has lots of bonds holding stuff together making is strong
• Gobular is soluble whilst fibrous is insoluble
• Globular proteins are metabolically active (involved in reactions) whilst fibrous proteins are structural
• Globular proteins roll up into balls (globules) whereas fibrous proteins from fibres
• Examples of globular proteins are enzymes, antibobies, haemoglobin and plasma proteins
• Examples of fibrous proteins are collagen, keratin, and elastin.
• Globular proteins are mainly alpha helix and fibrous proteins are mainly beta pleating