Interactions Between Cells and Their Enviroment

Organized network of secreted molecules that provides scaffolding to the cells and tissues it surrounds

extracellular matrix (ECM)

Virtually all integral membrane proteins, as well as certain membrane lipids, bear what of variable length that project outward from the plasma membrane

chains of sugars (oligosaccharides)

Carbohydrate chains of sugars form part of what

glycocalyx (or cell coat)

These carbohydrate projections form part of the glycocalyx (or cell coat) on which surface of the plasma membrane

outer

The Roles of the glycocalyx
– Mediator of cell–cell and cell–what interactions

substratum

The Roles of the glycocalyx
– what protection

Mechanical

The Roles of the glycocalyx
– Barrier to molecular what

movement

The Roles of the glycocalyx
– Binding sites for what factor

regulatory

Proteins in the ECM are typically are what

fibrous

ECMproteins are secreted to what space by certain cells

extracellular

ECM proteins interact with what proteins and can self-assemble into an interconnected 3D network

integral

The organized ECM network outside plasma membrane provides support and determines
shape and activity of what

cell

Components of the Extracellular Matrix

strength, structure

Fibrous proteins

Components of the Extracellular Matrix

gel-like consistency

Proteoglycans

Components of the Extracellular Matrix

organization, interactions

Non-Collagen Glycoproteins

The single most abundant protein in the human body, 28 distinct types

Collagen

fibronectin, laminin

Non-Collagen Glycoproteins

Proteoglycans can form very what structures

large

Glycosaminoglycans (GAGs) linked to what

proteins

Fibrous proteins are bundled into what

fibrils

All collagens are trimers, i.e., how many polypeptide (α chains)

3

Three α chains form fibril what helix

triple

what is produced by fibroblasts, smooth muscle and epithelial cells

Collagen

Collagen is the single most abundant protein in the human body (what % of all protein)

25

Collagens are what that are present only in extracellular matrices

glycoproteins

In tendons, the matrix is more or less fibrous and is maximized for tensile strength

more

well-defined ECM that forms a continuous sheet of 50-200 nm thick

Basement membrane/basal lamina

Basement membrane/basal lamina does what to nerve fibers, muscles, and fat cells

surrounds

Basement membrane/basal lamina does what to the inner endothelial lining of blood
vessels

underlies

Basement membrane/basal lamina does what to the basal surface of epithelial tissues

underlies

protein with covalently attached glycosaminoglycans

Proteoglycans

Long unbranched polysaccharide chains composed of repeating disaccharide units of two different sugars

Glycosaminoglycans (GAGs)

Glycosaminoglycans (GAGs) are highly what due to the presence of both sulfate and carboxyl groups

acidic

Glycosaminoglycans (GAGs) are a porous, hydrated what

gel

Glycosaminoglycans (GAGs) bind what numbers of water molecules

large

Giant proteoglycan complexes: Many linked to what

hyaluronic acid

Glycosaminoglycans (GAGs): Common in what

basement membrane

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