#Question id: 1376
#Unit 4. Cell Communication and Cell Signaling
Which of the following statements is NOT TRUE about gap junctions?
#Question id: 1377
#Unit 4. Cell Communication and Cell Signaling
Which of the following statements apply to both eukaryotic cell walls and animal cell extracellular matrices? Please select all that apply.
a) They are inflexible structures that support cells.
b) They are built to a common overall structure that can be described as 'fibres in a matrix'.
c) Their protein components are synthesized by ribosomes of the rough endoplasmic reticulum.
d) They limit the diffusion of ions and small molecules into the cell.
#Question id: 1378
#Unit 4. Cell Communication and Cell Signaling
Which of the following apply to fibronectins? Please select all that apply.
a) They are disulphide linked dimers, with each polypeptide composed of a number of binding domains joined together by short flexible segments.
b) They have an essential role in linking the extracellular matrix to its underlying cells.
c) Like integrins, fibronectins are directly connected to the cytoskeleton.
d) They participate in 'inside out' and 'outside in' signalling mechanisms.
#Question id: 1379
#Unit 4. Cell Communication and Cell Signaling
Which of the following statements apply to cellulose? Please select all that apply.
a) It is a polyglucose containing beta 1-6 glycosidic bonds.
b) It is a major component of plant cell walls
c) It is a polyglucose containing beta 1-4 glycosidic bonds.
d) It is a major component of Gram negative cell walls.
#Question id: 1380
#Unit 4. Cell Communication and Cell Signaling
Which of the following apply to the synthesis of plant cell walls? Please select all that apply.
a) Cellulose microfibrils are formed by cellulose synthase complexes called rosettes
b) Cellulose is synthesized using cytoplasmic ATP-glucose and deposited as microfibrils directly on the outer surface of the plasma membrane.
c) Matrix polysaccharides of plant cell walls are synthesized in the Golgi apparatus and exported to the cell wall by endocytosis.
d) The direction of cellulose microfibril growth is determined by the orientation of arrays of microtubules lying just below the plasma membrane.
#Question id: 1381
#Unit 4. Cell Communication and Cell Signaling
Match each definition with given terms
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1. Large family of structurally related, secreted, dimeric proteins that act as hormones and local mediators to control a wide range of biological functions in all animals. |
A. Rho |
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2. Cell-surface receptor in which the cytoplasmic domain either has enzymatic activity itself or is associated with an intracellular enzyme. |
B. TOR pathway |
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3. A crucial signaling protein in the PI-3-kinase–Akt signaling pathway, so named because it is the target of rapamycin. |
C. Enzyme-coupled receptor |
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4. A kinase that is involved in intracellular signaling pathways activated by cell-surface receptors and that phosphorylates inositol phospholipids at the 3 position of the inositol ring. |
D. Phosphoinositide 3-kinase |
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5. A group of monomeric GTPases that regulate both the actin and microtubule cytoskeletons. |
E. (TGFβ) superfamily |
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6. Cytoplasmic tyrosine kinase present at cell–matrix junctions in association with the cytoplasmic tails of integrins. |
F. Focal Adhesion Kinase |