BCH210H1 Lecture Notes - Lecture 1: Tryptophan, Globin, Polymerization

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melodyli

12 Sep 2018

School

UTSG

Department

Biochemical Engineering and Applied Chemistry

Course

BCH210H1

Professor

Reinhart Reithmeier

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BCH210H1 Full Course Notes

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Sickle cell: a single amino acid change (glu6val) in the (cid:574)-chain of hemoglobin causes sickle cell anemia, glu6val means that valine (v) replaces glutamate (e) in position 6 of the beta chain. 2: dna, rna (genes, mrna, trna, lipids (fats, cholesterol, hormones, sugars (energy = atp, small molecules (metabolites, vitamins) 3: polymerization processes for amino acids, sugars, and nucleotides: 4: the 4 nucleotide bases: purines pyrimidines, dna double helix: 6: the most boring amino acid: alanine (ala, a) Absorbed wavelength of light: 295 nm; emitted wavelength of light: 350 nm. Monitor conformational changes: structure of the zwitterionic form of an amino acid (whose side chain cannot be ionized): Zwitterion at neutral ph: the (cid:573)-carbon of an amino acid is an asymmetric centre: 7: polymerization of amino acids results in the formation of peptide bonds: peptide bond, amino acid side chains (r-groups) are either hydrophobic (non-polar) or hydrophilic (polar, charged)

Related Questions

Normal adult hemoglobin is called Hemoglobin A (Hb A). Ninety-eight percent of adult hemoglobin is Hb A and 2% is Hb A2. There are other forms of hemoglobin. For example, the developing fetus has a different kind of hemoglobin than most normal adults. Fetal hemoglobin (Hb F) is synthesized beginning at the third month of gestation and continues up through birth. After the neonate is born, hemoglobin F synthesis declines (because synthesis of the (chain declines) and hemoglobin A is synthesized. By the time the baby is six months old, 98% of its hemoglobin is Hemoglobin A. There is also a mutant form of hemoglobin called Hemoglobin S, which is found in persons with the disease sickle cell anemia. The disease sickle cell anemia is one of the major health problems facing the African-American community. The World Health Organization estimates that 250,000 babies world wide are born with sickle cell anemia. Currently there is no cure. A person afflicted with sickle cell anemia has inherited a defective gene from each parent. The defective gene is the one coding for the Î²-chain. The amino acid at position 6 on each Î² chain has been mutated from a glutamate to a valine. Normal Î± chains have a decreased affinity for the mutated Î² chains; thus assembly of the HbS tetramer is more difficult. Red blood cells containing HbS form a sickle shape because the Hb S molecules polymerize. Hb S molecules are more likely to polymerize when in the deoxygenated T form than in the oxygenated R form. The polymerized Hb deforms the normal discoid shape of the red blood cells, producing a sickle-shaped cell. The sickle shaped red blood cells become trapped in capillaries and organs, depriving the victim of adequate oxygen supply and causing chronic pain and organ damage.

Glover, R. E., Ivy, E. D., Orringer, E. P., Maeda, H., and Mason, R. (1999) Molecular Pharmacology 55, pp. 1006-1010.

Huang, J., Hadimani, S. B., Rupon, J. W., Ballas, S. K., Kim-Shapiro, D. B., and S. Bruce King (2002) Biochemistry 41, pp. 2466-2474.

S. Bruce King (2003) J.Clin. Invest., 111, pp. 171-172.

1) Why do you think Hb S has higher tendency to polymerize compared to Hb A?

1. The dominant motif found in hemoglobin and myoglobin is: a) twisted beta sheet b) beta barrel c) helix-loop-helix d) 7-TM 2. Myoglobin has how many polypeptide chains? A) 1 b) 2 c) 3 d) 4 3. Structurally and functionally, hemoglobin closely resembles a(n) a) transmembrane protein b) mucopolysaccharide c) bile salt d) allosteric enzyme 4. The oxygen binding site in hemoglobin and myoglobin is called: a) BPG b) heme c) proximal-His d) N-terminal carbamate 5. The proximal His residue in hemoglobin and myoglobin binds to which atom or molecule? A) CO2 b) O2 c) Fe d) BPG 6. The distal His residue in hemoglobin and myoglobin binds to which atom or molecule? A) CO2 b) O2 c) Fe d) BPG 7. BPG binds to: a) N-terminal carbamate b) proximal His c) heme group d) central cavity 8. Indirect activity of CO2 is a result of increased concentration of which chemical species? A) BPG b) H+ c) heme iron d) distal His 9. Direct activity of CO2 is a result of binding to which molecular feature? A) the heme group b) the N-terminal ends of the 4 polypeptide chains c) the central cavity d) the proximal His 10. The sigmoidal, cooperative binding curve commonly observed for hemoglobin is a result of: a) competition between CO2 and O2 for heme binding. B) competition between heme and distal His for O2 binding c) competition between BPG and CO2 for binding at the central cavity site d) T to R transition 11. Hemoglobin has a tendency to release its oxygen to the tissues because: a) in this region pH is high and O2 concentrations are low b) in this region both pH and O2 concentrations are low c) in this region both pH and O2 concentrations are high d) there is much BPG in this region 12. Which statement about fetal hemoglobin is not true? A) fetal hemoglobin has gamma chains instead of beta chains b) fetal hemoglobin binds BPG less strongly than maternal hemoglobin c) fetal hemoglobin binds oxygen less strongly than maternal hemoglobin d) fetal hemoglobin binds oxygen more strongly than maternal hemoglobin 13. Which process is most responsible for the sickling of cells seen in sickle cell disease? A) aggregation of the oxygenated R form of hemoglobin-S to form insoluble fibers b) aggregation of the deoxygenated T form of hemoglobin-S to form insoluble fibers c) Hemoglobin-S does not contain heme d) Hemoglobin-S contains a mutant form of heme which will not bind oxygen 14. A person with sickle-cell trait is very unlikely to catch which disease? A) malaria b) colon cancer c) avian flu d) whooping cough 15. A person with a genetic defect which results in the synthesis of an insufficient amount of the alpha chain of hemoglobin is said to have which disease? A) alpha thalassemia b) beta thalassemia c) pernicious anemia d) Crohnâs disease

1. Polypeptide strands is the active form of a digestive enzyme in the stomach that breaks polypeptide chains into smaller polypeptides.

2. Cleavage of proteins by pepsin in the stomach results in formation of pepsinogen which get broken down further in the small intestine.

3. An amino acid chain made up of three amino acids joined together is called a tripeptide.

4. Dipeptide describes an amino acid chain made up of two amino acids joined together.

5. The 20 different amino acids are the building blocks used for protein synthesis.

6. Amino acid pools are stockpiles found in the blood and other cells of the body that can be used to build new proteins.

7. The continual process of degrading and synthesizing protein is called protein turnover.

8. The stomach produces pepsin, which denatures protein.

9. Denaturation occurs when a protein is exposed to heat, acid, bases, or mechanical agitation resulting in unfolding of the protein, though the peptide bonds remain intact.

10. The part of an amino acid that contains nitrogen is called the amine group.

11. The acid group is also known as the carboxyl group.

12. Single amino acids that are absorbed in the small intestine travel to the liver via the portal vein.

Please correct these sentences AS SOON AS POSSIBLE.. Some of them are not correct and I didn't figure out what are they!

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BCH210H1 Lecture Notes - Lecture 1: Tryptophan, Globin, Polymerization

BCH210H1 Full Course Notes

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