Explain the following concepts in biochemistry: 1. Describe 4 organizational levels of the structure of proteins. 2. Describe the differences between myoglobin and haemoglobin.... Explain the following concepts in biochemistry: 1. Describe 4 organizational levels of the structure of proteins. 2. Describe the differences between myoglobin and haemoglobin. 3. What are the classes of antibodies? 4. A patient complains about the bleeding of his gum whenever he brushes his teeth. He mentioned that he is on a high protein diet in the last 6 months and hates fruits and vegetables. What is the cause of his bleeding gums? A. He is using a toothbrush with hard bristles. B. He suffers from scurvy. C. His flossing techniques is wrong. D. He suffers from osteogenesis imperfecta. 5. Classify amino acids in terms of its properties, its synthesis in the body and its metabolic fate. Explain each terminology with examples. 6. Briefly describe how 10 non essential amino acids are synthesized in our body. 7. Describe the process of dietary protein digestion and absorption. 8. Describe the concept of amino acid pool and protein turnover. 9. Explain the meaning of transamination, oxidative deamination & decarboxylation with examples. 10. Explain the metabolism of ammonia using a diagram. Read more

Here are concise answers to your biochemistry questions, covering protein structure, myoglobin vs. hemoglobin, antibody classes, scurvy, amino acid classification, non-essential amino acid synthesis, protein digestion/absorption, amino acid pool/protein turnover, transamination/deamination/decarboxylation, and ammonia metabolism.

I will provide concise answers to your biochemistry questions:

1. The four levels of protein structure are:
   • Primary: The sequence of amino acids.
   • Secondary: Localized folding patterns such as alpha-helices and beta-sheets, stabilized by hydrogen bonds.
   • Tertiary: The overall three-dimensional structure of a single polypeptide chain, stabilized by various interactions.
   • Quaternary: The arrangement of multiple polypeptide subunits in a multi-subunit protein.
2. Myoglobin stores oxygen in muscle cells, while hemoglobin transports oxygen in red blood cells throughout the body.
3. The classes of antibodies (immunoglobulins) are: IgA, IgD, IgE, IgG, and IgM.
4. The patient likely suffers from scurvy (B). This is due to a deficiency in vitamin C, which is essential for collagen synthesis and leads to bleeding gums. His high protein diet and lack of fruits and vegetables contribute to this deficiency.
5. Amino acids can be classified by:
   • Properties: Nonpolar, polar, acidic, and basic.
   • Synthesis: Essential (must be obtained from the diet) and non-essential (can be synthesized in the body).
   • Metabolic Fate: Glucogenic (can be converted to glucose), ketogenic (can be converted to ketone bodies), or both.
6. Non-essential amino acids are synthesized through various metabolic pathways, often involving transamination reactions and precursors from glycolysis or the citric acid cycle. For example, alanine is synthesized from pyruvate by transamination.
7. Dietary protein digestion begins in the stomach with pepsin and continues in the small intestine with pancreatic proteases. Amino acids, dipeptides, and tripeptides are absorbed into enterocytes, further broken down, and then transported into the bloodstream.
8. The amino acid pool refers to the free amino acids present in the body, available for protein synthesis and other metabolic processes. Protein turnover is the continuous synthesis and degradation of proteins.
9. • Transamination: The transfer of an amino group from one amino acid to a keto acid, catalyzed by transaminases (e.g., alanine transaminase). Example: Alanine + α-ketoglutarate ↔ Pyruvate + Glutamate.
   • Oxidative Deamination: The removal of an amino group from an amino acid, producing ammonia and a keto acid, often catalyzed by glutamate dehydrogenase.
   • Decarboxylation: The removal of a carboxyl group from an amino acid, producing an amine and carbon dioxide (e.g., histidine to histamine).
10. Ammonia metabolism involves the urea cycle, which converts toxic ammonia into urea for excretion. The process starts in the mitochondria, where ammonia combines with carbon dioxide and ornithine to form citrulline. Citrulline is then transported to the cytoplasm to continue the urea cycle, eventually producing urea.