Term
| Tell me the structural levels of collagen in order from simplest to complex... |
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Definition
1) Primary sequence
2) Minor helix
3) Triple helix
4) Tropocollagen
5) Fibril formation
6) Fibers |
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Term
| What is added to collagen to form bone? |
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Definition
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Term
| Why is proline hydroxylated to hydroxyproline? |
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Definition
1) inter-tropocollagen hydrogen bonding stabilizes collagen fibril
2) stereoelectronic effect which fixes the proline pyrrolidine ring pucker in the triple helix pre-organizes all 3 main-chain torsion angles |
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Term
| The collagen triple helix (3 type II helices) is stabilized by? |
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Definition
| inter-strand hydrogen bonding |
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Term
| Collagen is formed from a preprocollagen? What is the purpose of the pre and what is the purpose of the pro? |
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Definition
pre- signal sequence of collagen to target it to the RER
pro- N- and C- terminal sequences that are cleaved after secretion forming tropocollagen |
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Term
| RER- Collagen Synthesis- Tell me what step is this in the formation and what happens here? |
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Definition
| 1st step- synthesized as preprocollagen, insertion of procollagen into the luman of the ER |
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Term
| Luman of ER- Collagen Synthesis- Tell me what step is this in the formation and what happens here? |
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Definition
| 2nd step- hydroxylation of Pro & Lys, glycosylation of hydroxylysine |
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Term
| Luman of ER &Golgi- Collagen Synthesis- Tell me what step is this in the formation and what happens here? |
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Definition
| 3rd step- self-assembly and triple helix formation initiated by di-sulfide formation in the C-terminal extension (pro part of protein) |
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Term
| Secretory Vesicle- Collagen Synthesis- Tell me what step is this in the formation and what happens here? |
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Definition
| 4th step- procollagen prepared for secretion from cell, tropocollagen molecule secretion |
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Term
| Extracellular- Collagen Synthesis- Tell me what step is this in the formation and what happens here? |
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Definition
| 5th step- trimming of pro-peptides, self-assembly of collagen molecules into fibrils and then fibers |
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Term
| What are the functions of the Procollagen C-termini? |
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Definition
1) necessary for nucleation of triple helix formation and association of 3 polypeptide chains
2) inter-strand disulfide bonds stabilize growing triple helix |
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Term
| What is the function of the procollagen N-temini? |
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Definition
1) proper alignment of procollagen molecules in fibril
2) feedback control of net collagen synthesis
3) regulation of growth factor activity in extracellular matrix |
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Term
| The C-terminus has what type of cystines or disulfide bonds? |
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Definition
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Term
| The N-terminus has what type of cystines or disulfide bonds? |
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Definition
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Term
| What are the unique cross-links found in elastin? What are they made of? |
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Definition
| Desmosine-made from 4 Lys residues |
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