Collagen

COLLAGEN STRUCTURE AND FUNCTION

Proteins are the most diverse class of biological molecules. Most of your body is made up of proteins. Each protein consists of one or more polypeptide chains, in which amino acids are strung together in a specific order. This amino acid sequence or 'primary structure' is the key to the shape and function of the protein. Interactions among different amino acids along the length of the polypeptide chain cause it to coil, bend, and fold into a complex shape.  Some proteins consist of two or more polypeptide chains. In many cases, the polypeptide chains form a rounded or globular shape. Most enzymes are like this, as is the oxygen-carrying hemoglobin molecule. In other cases, polypeptide chains form long strands or sheets. These fibrous proteins are often structural components, such as keratin and collagen.

Activity

In this activity, you will explore the structure and function of collagen, the most abundant protein in the human body. You will begin by visiting a Protein Data Bank site, where the structure of collagen is described and illustrated in a "Molecule of the Month" feature. Next, you will research the effects of osteogenesis imperfecta (OI), a genetic disorder that affects the structure or number of collagen molecules.

Part 1.

Use your browser to go to

Find the link in the middle of the page to “previous features” under the molecule of the month section.  Click there to find the article on collagen in the alphabeticall listing of molecules.

Read the information and view the graphics. Use this information to answer the following questions:

1. Describe the primary structure of collagen. What are the major amino acid components?

The primary action is to strengthen the tendons and vast, resilient sheets that support the skin and internal organs. Every third acid is glycine.

2. What role does vitamin C play in collagen formation? What happens when a person does not get enough vitamin C in his or her diet?

Hydroxyproline is made. If a person doesn’t have enough vitamin c they devolop scurvy

3. Describe the quaternary structure of collagen (the way in which the polypeptide chains are arranged).

Collegen is arranged in a triple helix. Every third amino acid is glycine

Part 2.

Use your browser to go to the Web site of the Osteogenesis Imperfecta Foundation at

On the left side of the home page, click the link “About OI”, then find the “Facts About OI” section.

Read the material in the sections entitled "Facts on Osteogenesis Imperfecta” and “Types of OI.” Use what you have learned to answer the following questions:

1. What is the main symptom of osteogenesis imperfecta?  What are some other symptoms that people with OI may have?

The main sympton is fragile bones. They also have muscle weakness, hearing loss, fatigue, joint laxity, curved bones, scoliosis, blue sclerae, dentinogenesis imperfecta (brittle teeth), and short stature. Restrictive pulmonary disease occurs in more severely affected people.

2. Type I osteogenesis imperfecta causes fewer problems than the other forms. How does the collagen structure in Type I OI differ from that of the other types?

Type one is caused by mutation to type 1 collegen, while

Others is caused by mutations of the cartilage-associated protein

Read the handout in the resources section on Bone Structure (opens in Acrobat Reader).

1. Describe the role of collagen in bones. Why do collagen problems lead to bone problems?

  Collagen helps make bones healthy and strong.  Collagen is like rebar in a concrete wall. It strenghthens it. If there wasn’t any rebar in the wall then it would be weak.