Mokrzan Study Guide (exam 3, pt 1 = ECM) Flashcards
The ECM is a complex network of _______ in the extracellular space
The ECM is a complex network of MACROMOLECULES in the extracellular space
The ECM is secreted by ________
The ECM is secreted by THE CELLS THAT INHABIT IT
The ECM gives ____ and ____ support to tissues
The ECM gives STRUCTURAL and ORGANIZATIONAL support to tissues
T/F: The ECM only makes up a small part of the tissue volume
FALSE!! The ECM makes up a SUBSTANTIAL part of the tissue volume
Collage accounts for _____% of total body protein
Collagen accounts for 30% of total body protein
_____% of collagen is Type 1
90% of collagen is type 1
What is type I collagen?
Type I collagen is a FIBRILLAR class, with distributions to SKIN, TENDON, TEETH, and BONES
What are the 4 main families of molecules that comprise the ECM?
4 main families comprising the ECM include…
- Collagens
- Elastins
- Glycoproteins
- Proteoglycans
There are Fibrillar and non-fibrillar collagens. Type IV is a non-fibrillar (network, to be specific) class which is found in ________.
There are Fibrillar and non-fibrillar collagens. Type IV is a non-fibrillar (network, to be specific) class which is found in BASEMENT MEMBRANES, KIDNEYS, and VASCULAR WALLS, and the GLOMERULUS
T/F: The collagen composition is highly consistant in different tissues
FALSE!! • Different types and combinations of collagen molecules predominate in different tissues
Collagen is frequently remodeled, and synthesis is affected by physiologic conditions such as
______ and _______
Collagen is frequently remodeled, and synthesis is affected by physiologic conditions such as
DIET and MECHANICAL STRESS
note: half life of collagen in relevant tissues incl:
-Perio ligament = 2 days
-Gingiva = 5 days
-Alveolar bone = 6 bays
-Skin = 15 days
Osteogenesis/dentogenesis imperfecta is the result of a genetic mutation that causes ___________ to be replaced by another amino acid
Osteogenesis/dentogenesis imperfecta is the result of a genetic mutation that causes THE GLYCINE IN TYPE I COLLAGEN to be replaced by another amino acid
______% of TOTAL BODY PROTEIN is TYPE I collagen
27% of TOTAL BODY PROTEIN is TYPE I collagen (90% of all collagen is type 1, and collagen is 30% of total body protein)
How are intra- and inter- chain helices stabilized?
H-bonding stabilizes the helices of collagen
Elastin provides ______ and _____ to the ECM
Elastin provides FLEXIBILITY and RESILIENCE to the ECM
Elastin is the predominant ECM molecule in _________
Elastin is the predominant ECM molecule in BLOOD VESSELS (note: also abundant in skin, lungs, and intestines)
Elastin is found in tissues that require ______
Elastin is found in tissues that require ELASTICITY
Elastin is stabilized by _______
Elastin is stabilized by TWO-WAY CROSSLINKS
Elastin crosslinks contain ________
Elastin crosslinks contain DESMOSINE
________ is not synthesized after adolescence
ELASTIN is not synthesized after adolescence
What are the 2 types of Glycoproteins found in the ECM
FIBRONECTIN and LAMININ are are two types of glycoproteins found in the ECM
Fibronectin facilitates communication between ________ and ________ compartments
Fibronectin facilitates communication between INTRACELLULAR and EXTRACELLULAR compartments
___________ of the ECM binds to membrane-spanning receptor proteins called integrins
FIBRONECTIN of the ECM binds to membrane-spanning receptor-proteins called integrins
Fibronectin binds with _______ such as collagen and fibrin
Fibronectin binds to OTHER ECM MOLECULES such as collagen and fibrin
All 20 known types of fibronectin (both soluble and insoluble) are produced by _________
All 20 known types of fibronectin (both soluble and insoluble) are produced by ALTERNATIVE SPLICING OF A SINGLE PRECURSOR mRNA
What are the 6 major/general roles of Fibronectin?
Fibronectin plays a major role in…
- Cell adhesion
- Growth
- Differentiation
- Embryogenesis
- Migration
- Wound healing
How does Fibronectin help with wound healing?
Along with fibrin,plasma fibronectin is deposited at the site of injury, forming a blood clot that stops bleeding and protects the underlying tissue
There are both ____ and ______ forms of fibronectin
There are both SOLUBLE and INSOLUBLE forms of fibronectin
________ prevents S. mutans, P. gingivalis, and other oral pathogens from binding to the oral cavity
SOLUBLE FIBRONECTIN IN SALIVA prevents S. mutans, P. gingivalis, and other oral pathogens from binding to the oral cavity
Alternative splicing is controlled by what 4 factors/processes?
Alternative splicing is controlled by….
- Tissue or cell of origin
- Embryogenesis
- Wound healing
- Oncogenesis
_______ is found primarily in the basal lamina
LAMININ is found primarily in the basal lamina
Laminin gives structural support to ______
Laminin gives structural support to THE ECM (intergral part of ECM “scaffolding”)
Laminin is a component of basement membranes in _____ and _____ tissues
Laminin is a component of basement membrane is EPITHELIAL and MUSCLE tissues
Laminin binds to cells, often through the ______
Laminin binds to cells, often through the INTEGRIN FAMILY OF PROTEINS
Defective laminin cause what 3 diseases?
Defective laminin causes….
- Muscular dystrophy
- Lethal skin blistering disease (epidermolysis bullosa)
- Defects of kidney filter
Proteogylcans are the ______ of the ECM
Proteogylcans are the GEL-FORMERS of the ECM
Describe the structure of proteoglycans
Amino acids (proteins) are linked to a chain of GlcNAc/N-acetylglucosamine, Galactose, and Glucuronic acid by a Xylose.
Describe the diversity of proteoglycans
Proteoglycans can vary in structure and distribution. Specifically, various proteoglycans will have different characteristic disaccharides, sulfide sources (sulfation), and tissue location (joint, bone, cells, cornea, etc)
Proteoglycans have _______ charges, which attract cations and water. The result is ______ of the ECM, which provides rigidity and ______.
Proteoglycans have MANY NEGATIVE charges, which attract cations and water. The result is HYDRATION of the ECM, which provides rigidity and DURABILITY (withstands compressional forces!!)
<p>
| Proteoglycans are \_\_\_\_% of ECM protein, but because of their hydrophilicity, \_\_\_\_\_ chains fill most of the EC space</p>
<p>
| Proteoglycans are <10% of ECM protein, but because of their hydrophilicity, GAG chains fill most of the EC space</p>
Describe Aggrecans
Aggrecan are a type of proteoglycan that is found alongside collagen as the main components of cartilage. The negative charges on the repeating GAG units of aggrecan attract water absorption.
As a result, aggrecan acts as a cushion for impact retention by absorbing and desorbing water.
This role is particularly important in between joints that sustain high amounts of impact in mammalian bodies, such as the knees.
What are the tissue-specific functions of proteoglycans?
Tissue-specific functions of proteoglycans include….
- Bind Growth Factors
- Regulate enzyme activity of secreted proteins
- Act as co-receptors
Describe Mucopolysaccharidoses
Mucopolysaccharidoses, are a group of genetic diseases related to proteoglycans and lysosomal storage problems.
The inactivity of specific lysosomal enzymes that normally degrade GAGs leads to the accumulation of proteoglycans within cells. This leads to a variety of disease symptoms.
The ECM regulates ______
The ECM regulates CELLULAR PROCESSES
Collagen provides ______ and _____ to the ECM
Collagen provides STRENGTH AND STRUCTURE to the ECM
Glycoproteins provide ______ and ______ to the ECM
Glycoproteins provide STRUCTURE and CELL ADHESION to the ECM
Alterations in ECM characteristics can lead to ____________
Alterations in ECM characteristics can lead to CHRONIC DISEASES
