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Line 1: |
| __NOTOC__ | | __NOTOC__ |
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| {{CMG}} {{MIR}} | | {{CMG}} {{MIR}} |
| Ribosomes are made of proteins and rRNA | | Ribosomes are made of proteins and rRNA |
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Line 63: |
| *** Secondary structure → Beta and alpha pleated | | *** Secondary structure → Beta and alpha pleated |
| *** Tertiary structure | | *** Tertiary structure |
| Purine synthesis:
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| You need glycine, glutamine and aspartate + tetrahydrofolate (Folic acid) + CO2
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| Rate limiting step : Glutamine PRPP amidotransferase
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| Carbon sources:
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| CO2, glycine, tetrahydrofolate
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| Nitrogen sources
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| Aspartate + Glutamine
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| Pyrimidines: Aspartate + carbamoyl phosphate (1 carbon and 1 nitrogen [glutamine]) + ATP
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| Carbamoyl phosphate → Has 1 carbon and 1 nitrogen
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| You need aspartate + CO2 + glutamine + ATP (Last 3 come from carbamoyl phosphate)
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| Carbamoyl phosphate synthetase 2 (RATE LIMITING STEP)
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| Start with orotic acid then add a base
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| Carbon sources:
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| Aspartate
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| CO2
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| Glutamine → Gives nitrogen
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| CPS 1 + CPS 2
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| CPS 1
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| Mitochondria
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| Urea cycle
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| Use nitrogen from ammonia
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| CPS 2
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| Cytosol
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| Pyrimidine synthesis
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| Use nitrogen from glutamine
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| Orotic aciduria
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| Deficiency of UMP synthase
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| AR
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| Elevated oritic acid
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| Megaloblastic anemia
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| Not corrected with B12 or folic acid
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| No hyperammonemia
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| Treat with uridine
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| Ornithine Transcarbomylase Deficiency
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| Causes hyperammonemia
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| Elevated orotic acid
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| Problem with urea cycle
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| Dantrolene → Prevents release of calcium from SR of skeletal muscle
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| Inhibit reuptake of norepinephrine:
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| Cocaine
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| TCA
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| Ribosomes are synthesized in the nucleus and transported into the cytoplasm.
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| Ribosomes are made of proteins and rRNA
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| Eukaryotes → 60 and 40s = 80s
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| Prokaryotes → 50 s and 30 s = 70 s
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| Have 23s in 50s
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| Translation
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| Initiation
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| IF1, IF2, If3
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| Assist in assembly of smaller ribosomal subunit to first trna molecule
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| Methionine is always the start
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| f-Methionine in prokaryotes
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| IF-2 first binds to 30s and then to methionine tRNA. Then when 50s comes along, it hydrolyzes GTP on IF2 and allows 50s to attach to 30s
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| A site → Incoming aminoacyl TRNA binds
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| P site → Polypeptide binds (Growing chain)
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| First tRNA binds here
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| E site → Free tRNA (exit)
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| Elongation
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| Incoming charged aminoacyl TRNA binds to A site
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| Elongation factor help incoming trna to bind to A site (Uses GTP)
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| 50s has peptidyl transferase transfers AA from p site to A site
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| In prokaryotes, activity is in 23s subunit of 50s rRNA
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| Translocation
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| Ribosome complex moves 3 nucleotides
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| tRNA + Peptide is moved from A site to P site
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| Newly uncharged tRNA from P side to E side
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| EF-G → Eukaryotes
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| EF-2 in eukaryotes
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| Diptheria and exotoxin (Pseudomonas) inhibit this
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| Termination
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| Stop codons
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| UGA, UAA and UAG
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| Signal to STOP
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| No new TRNA coming
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| Release factor binds to MRNA and hydrolyzes GTP and new polypeptide is released.
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| Antibiotics
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| Aminoglycosides → Inhibit 30s subunit before initiation (No pairing with TRNA)
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| Linezolid → Inhibits initiation by binding to 50s subunit
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| Tetracycline
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| Bind to 30s subunit
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| Prevent aminoacyl TRNA from binding to A site
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| Chloramphenicol
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| Inhibits peptidyl transferase
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| Binds to 50s
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| Macrolides
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| Inhibits translocation by binding to 50s subunit
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| Clindamycin
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| Same as macrolides
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| Lincamycin
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| Bind to 50s and inhibit translocation
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| Streptrogranin
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| Bind to 50s and inhibit translocation
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| Buy AT 30 ,CCELL at 50
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| Post translational modification
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| Trim terminals
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| Covalent modification
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| Glycosylation, hydroxylation, phosphorylation
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| Collagen → Hydroxylation of proline and lysine
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| Disulfide bonds
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| Protein folding
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| Primary structure → Chain
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| Secondary structure → Beta and alpha pleated
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| Tertiary structure
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Mahshid Mir, M.D. [2]
Ribosomes are made of proteins and rRNA
- Eukaryotes → 60 and 40s = 80s
- Prokaryotes → 50 s and 30 s = 70 s
Translation
- Initiation
- IF1, IF2, If3
- Assist in assembly of smaller ribosomal subunit to first trna molecule
- Methionine is always the start
- f-Methionine in prokaryotes
- IF-2 first binds to 30s and then to methionine tRNA. Then when 50s comes along, it hydrolyzes GTP on IF2 and allows 50s to attach to 30s
- A site → Incoming aminoacyl TRNA binds
- P site → Polypeptide binds (Growing chain)
- E site → Free tRNA (exit)
- Elongation
- Incoming charged aminoacyl TRNA binds to A site
- Elongation factor help incoming trna to bind to A site (Uses GTP)
- 50s has peptidyl transferase transfers AA from p site to A site
- In prokaryotes, activity is in 23s subunit of 50s rRNA
- Translocation
- Ribosome complex moves 3 nucleotides
- tRNA + Peptide is moved from A site to P site
- Newly uncharged tRNA from P side to E side
- EF-G → Eukaryotes
- EF-2 in eukaryotes
- Diptheria and exotoxin (Pseudomonas) inhibit this
- Termination
- Stop codons
- UGA, UAA and UAG
- Signal to STOP
- No new TRNA coming
- Release factor binds to MRNA and hydrolyzes GTP and new polypeptide is released.
- Antibiotics
- Aminoglycosides → Inhibit 30s subunit before initiation (No pairing with TRNA)
- Linezolid → Inhibits initiation by binding to 50s subunit
- Tetracycline
- Bind to 30s subunit
- Prevent aminoacyl TRNA from binding to A site
- Chloramphenicol
- Inhibits peptidyl transferase
- Binds to 50s
- Macrolides
- Inhibits translocation by binding to 50s subunit
- Clindamycin
- Lincamycin
- Bind to 50s and inhibit translocation
- Streptrogranin
- Bind to 50s and inhibit translocation
- Buy AT 30 ,CCELL at 50
- Post translational modification
- Trim terminals
- Covalent modification
- Glycosylation, hydroxylation, phosphorylation
- Collagen → Hydroxylation of proline and lysine
- Disulfide bonds
- Protein folding
- Primary structure → Chain
- Secondary structure → Beta and alpha pleated
- Tertiary structure