Term
| What are the 3 components of ECM |
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Definition
1. Collagens 2. Protetoglycans 3. Multiadhesive matrix proteins |
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Term
How are collagen helices composed? |
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Definition
Trimeric proteins made from three polypepdtides called collagen alpha chains Each alpha chain is twisted left-handed helix, three of these helices wrap around each other to form a RIGHT-handed helix. TWIST LEFT, WRAP RIGHT |
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Term
| (T/F) Proline stabilizes collagen triple helix and Glycine is present inside. |
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Definition
TRUE! Opposite of alpha helix where proline and glycine are helix breakers |
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Term
| How is collagen organized in skin, tendons, and bone? |
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Definition
skin- woven tendons-parallel bundles bone and cornea-parallel layers |
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Term
| What structure (primary, secondary, tertiary, etc) of collagen is STARBURST (Starbux according to Windsor) |
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Definition
Primary The only one with GELATIN! |
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Term
| (T/F) Collagen is composed of alpha helices |
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Definition
FALSE They are made of alpha CHAINS...big difference |
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Term
What type of collagen is in: Skin, tendon, bone, ligaments, dentin, interstital tissues |
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Definition
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Term
| What type of collagen is in: Cartilage, vitreous humor? |
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Definition
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Term
| What type of collagen is present in skin, muscle, blood vessels? |
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Definition
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Term
| What type of collagen is present in Cornea, teeth, bone, placenta, skin, and smooth muscle? |
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Definition
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Term
| Describe how collagen is formed |
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Definition
1. Secreted as procollagen chains 2. In the ER-lysines and prolines are hydroxylated 3. These hydroxylated lysines and prolines stablize 4. Disulfide bonds align 3 chains, form trip. helix |
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Term
| Why are propeptides removed AFTER secretion of fibrillar procollagen. |
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Definition
To prevent collagen formation inside cells! Also the lysyl oxidase is an extracellular enzyme. |
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Term
| What does lysyl oxidase and where is it located. |
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Definition
It is a extracellular and causes the formation of crosslinking between collagen and elastin fibers. It forms aldehydes |
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Term
What hydrolyses proline, what is it's cofactor, and what disease does it prevent? |
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Definition
Prolyl 4-hydroxylase Vitamin C Scurvy! ARRRRRRGH |
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Term
| When collagen chains are not hydroxylated sufficiently, aka no hydroxyproline, what disease occurs? |
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Definition
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Term
| What collagen type resembles chickenwire? |
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Definition
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Term
| What syndromes are associated with type IV collagen mutations? |
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Definition
Mutation of the C-terminal globular domain causes Alport's syndrome-renal problems Auto-antibodies that bind to the alpha 3 results in Goodpasture's syndrome (renal problems) |
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Term
| What are MMPs and their function? |
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Definition
Matrix metalloproteinases They cleave collagens and other matrix components Involved in ECM normal healthy remodeling as well as pathological conditions such as arthritis, cancer, asthma, and periodontal disease. |
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Term
| When MMPs, specifically collagenases, cleave collagen, what are the characteristic fragments? |
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Definition
3/4 amino terminal 1/4 carboxy-terminal fragments. |
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Term
What components of the ECM or insoluble and which are soluble? |
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Definition
Collagens are INSOLUBLE Multiadhesive proteins and proteoglycans are SOLUBLE |
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Term
| What are the roles of the Basal Lamina |
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Definition
Separates epithelial cells from the underlying connective tissue. Functions as a highly selective filter Plays a structural role (cell polarity, metabolism, induces differentiation, and guids migration) |
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Term
The basal lamina is composed mostly of what type of collagen? |
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Definition
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Term
| What type of multiadhesiveprotein is the second most abundant protein in the basement membrane (behind collagen IV) |
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Definition
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Term
| What mutation in elastin cuases Marfan's syndrome? |
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Definition
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Term
| What accounts for the volume of ECM? |
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Definition
| Proteoglycans and the highly charge polysaccharides of tehir GAGs |
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Term
| What is the most abundant proteoglycan in cartilage? |
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Definition
aggrecan! Accounts for cartilage's gel-like properties |
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Term
| What is the most common cell surface proteoglycan? |
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Definition
Syndecan! binds collagen and fibronectin using heparin sulfate is a component of plasma membrane and has a membrane-spanning core protein. |
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Term
| What is hyaluronan (HA) and what is its function? |
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Definition
HA is a REALLY long negative polysaccharide. Major structural component of PG that make up ECM Only sugar not linked to protein!!! Ballon in container (joint demo) |
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