Term
| What do hydophilic amino acids do? |
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Definition
| important in controlling extracellular pH |
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Term
| What do hydrophobic proteins do? |
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Definition
They are important in the determination of conformational shapes, subunit binding (e.g., the association of more than one polypetptide chain), reactive site formation and function, as well as the existence of some proteins in the cell membranes. |
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Term
| What amino acid promotes metal chelation in hemoglobin? |
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Definition
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Term
| Which amino acid promotes chain binding in ribonuclease? |
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Definition
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Term
| What makes alpha and beta crystallines more stable than gamma crystallines? |
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Definition
| The N terminus in alpha and beta crystallines is acetylated |
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Term
| What is the only type of crystalline found in the lense epithelium? |
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Definition
| alpha crystalline, Alpha, Beta, and Gamma subtypes all occur in the lens fiber cells |
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Term
| What is the difference between glycoslyation and glycation? |
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Definition
| Glycosylation is the enzymatic addition of a sugar molecule to a protein and is not age related. Glycation is the nonenzymatic addition of a sugar to a protein and is age related. |
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Term
| Name four processes that crystallines can undergoe due to aging in the lens. |
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Definition
phosphorylation
disulfide bond formation
deamidation
peptide bond disruption |
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Term
| In which type of crystallines are you most likely to see disulfide bond formation? |
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Definition
Gamma crystallines due to cysteine content |
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Term
| Do HM4 nuclear cataracts link by disulfide bonds? |
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Definition
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Term
| What protein stops rhodopsin from migrating around the disc? |
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Definition
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Term
| What is the apoprotein of rhodopsin? What is the prosthetic group? |
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Definition
| The apoprotein is called opsin, while the prosthethic group is retinal or viatamin A |
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Term
| What enzyme helps regenerate rhodopsin by changing the trans retinal to cis retinal? |
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Definition
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Term
| What do the conditions of ocular pemphigoid (conjunctival ulcerations), Stevens Johnson syndrome, , and vitamin A deficiency have in common? |
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Definition
| They act by bringing about destruction of the goblet cells decreasing TBUT even when aqueous layer volume is adequate. |
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Term
| What is the role of type V collagen in the corneal stroma? |
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Definition
| limits the diameter of type I fibers and thus prevents light scattering in the cornea |
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Term
| What limits the diameter of type II collagen in the vitreous? |
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Definition
| type V-XI collagen, this collagen also surrounds the proteoglycans of the vitreous |
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Term
| What type of collagen is found in basement membranes such as Bowman's membrane, the lens capsule and blood vessels? |
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Definition
| type IV and type VIII collagen |
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