Hemoglobin and Collagen: Answers PDF

## Answers 1. Globular hemeproteins have heme as a **prosthetic** group. A prosthetic group is a non-protein molecule that is essential for the biological activity of a protein. 2. Myoglobin functions as a reservoir for **oxygen**. Myoglobin plays a crucial role in oxygen storage and tran...

## Answers 1. Globular hemeproteins have heme as a **prosthetic** group. A prosthetic group is a non-protein molecule that is essential for the biological activity of a protein. 2. Myoglobin functions as a reservoir for **oxygen**. Myoglobin plays a crucial role in oxygen storage and transportation within muscle tissue. 3. The structure of myoglobin is primarily composed of **alpha** helices. Myoglobin features a high alpha-helical content, contributing to its stable structure. 4. The interior of myoglobin is composed of **nonpolar** amino acids. Nonpolar amino acids help stabilize the structure of myoglobin through hydrophobic interactions. 5. Charged amino acids on the surface of myoglobin form **hydrogen** bonds with each other. Surface interactions among charged amino acids are important for maintaining the stability and solubility of proteins. 6. One molecule of 2,3-BPG binds to a pocket in the center of the deoxyhemoglobin **tetramer**. Hemoglobin is made up of four subunits, forming a tetramer, which is crucial for its function. 7. In response to chronic hypoxia, the concentration of 2,3-BPG in red blood cells **increases**. Chronic conditions like obstructive pulmonary emphysema or high altitudes lead to an increase in 2,3-BPG levels. 8. Increasing levels of 2,3-BPG decreases the **oxygen** affinity of hemoglobin. Lowering oxygen affinity facilitates the unloading of oxygen to the tissues that need it. 9. Chemicals used to preserve blood cause a decrease in 2,3-BPG, making blood an 'oxygen **trap**'. When blood has a very high affinity for oxygen, it does not release enough oxygen to the tissues. 10. To counteract the decrease in 2,3-BPG in preserved blood, **inosine** can be added. Inosine is a compound that helps restore levels of 2,3-BPG for effective oxygen transport. 11. The proximal histidine, known as F8, binds the iron of **heme**. Heme is an iron-containing compound that is essential for oxygen binding in myoglobin and hemoglobin. 12. Hemoglobin A consists of two ?-chains and two **ß** chains. The two types of chains in hemoglobin A are essential for its quaternary structure and function in oxygen transport. 13. Myoglobin can only carry **one** molecule of oxygen. Myoglobin is designed to store oxygen in muscle tissues, which is different from hemoglobin's capacity to transport more oxygen. 14. Hemoglobin has **four** binding sites, one in each subunit. The four heme binding sites allow hemoglobin to transport multiple molecules of oxygen. 15. The T-form of hemoglobin is also known as the taut or **tense** form. The tense form of hemoglobin is associated with low affinity for oxygen. 16. Polypeptide chains within each dimer of hemoglobin are held together primarily by **hydrophobic** interactions. Hydrophobic interactions help stabilize the structure of hemoglobin's dimers. 17. Hemoglobin can transport both H+ and **CO2** from tissues to the lungs. This ability allows hemoglobin to play a role in maintaining acid-base balance in the body. 18. The two dimers in hemoglobin are held together by **polar** bonds. Polar bonds help maintain the structure of hemoglobin while allowing flexibility between the dimers. 19. CO2 binding stabilizes the T-form (deoxy form) of hemoglobin, causing a decrease in **oxygen** affinity. The binding of CO2 to hemoglobin lowers its affinity for oxygen to facilitate oxygen release. 20. Collagen has a repeating sequence of -Gly- **X, Y** -Gly- The X and Y positions in the collagen sequence are typically occupied by proline and either hydroxyproline or hydroxylysine, respectively. 21. CO is very toxic because its affinity for hemoglobin is **220** times greater than that for oxygen. Carbon monoxide binds to hemoglobin more tightly than oxygen, leading to reduced oxygen delivery to tissues. 22. Hyp stabilizes the triple-helical structure of collagen by maximizing interchain **hydrogen** bond formation. Hydrogen bonds between collagen chains are crucial for maintaining the stability of the triple helix. 23. Fetal hemoglobin (HbF) has a higher affinity for **oxygen** than adult hemoglobin (HbA). HbF's strong affinity for oxygen allows effective oxygen transfer from the mother to the fetus. 24. HbA1c is formed when hemoglobin is slowly **glycosylated** under physiological conditions. The glycosylation of hemoglobin A results in HbA1c, which is monitored in diabetic patients. 25. Vitamin C deficiency can lead to **scurvy**, which results in fragile capillaries and excessive bruising. Scurvy is a condition caused by a lack of Vitamin C, affecting collagen strength and structure. 26. In collagen, proline at position X is essential for **helical** conformation of each a-chain. Proline contributes to the stability of the helical structure in collagen chains, preventing them from forming standard alpha-helices. 27. Collagen is the most abundant **protein** in the human body. Collagen plays a critical structural role in various tissues throughout the body. 28. The hydroxyl group of hydroxylysine can be glycosylated by adding glucose and **galactose** to the polypeptide chain. Glycosylation involves the addition of specific sugar molecules, which can affect the function and stability of collagen. 29. Fibril-forming collagen type I is found in skin, bone, tendon, blood vessels, and **cornea**. Type I collagen is essential for providing structural integrity across multiple tissues. 30. Fibrous proteins, including collagen and elastin, are primarily responsible for **structural** functions. These proteins contribute to the mechanical strength and resilience of various tissues. 31. Type IV collagen forms the **basement** membrane. The basement membrane is crucial for supporting and anchoring epithelial cells.