Question 1

EDTA is a divalent cation chelator.Propose an explanation for how EDTA promotes the dissociation of animal cell tissue?

Accepted Answer

Much of cell-cell adhesion is mediated by cadherins.Cadherin interactions between cells are Ca²⁺ dependent.EDTA chelates divalent cations,including Ca²⁺,leading to dissociation of cadherin cell-cell interactions.

Question 2

NCAMs,a group of cell-adhesion proteins belonging to the Ig superfamily:

Accepted Answer

A) are more heavily sialylated in embryonic tissues than in adult tissues. 
B) bind to proteoglycans. 
C) mediate Ca²⁺-dependent cell-to-cell binding. 
D) all of the above 
A) are more heavily sialylated in embryonic tissues than in adult tissues. 
B) bind to proteoglycans. 
C) mediate Ca²⁺-dependent cell-to-cell binding. 
D) all of the above D

Question 3

Pectins and hyaluronic acid are both:

Accepted Answer

A) secreted by animal cells. 
B) very negatively charged. 
C) proteins. 
D) intracellular substances. 
A) secreted by animal cells. 
B) very negatively charged. 
C) proteins. 
D) intracellular substances. B

Question 4

What is the oligomeric structure of integrins?

Accepted Answer

Integrins are heterodimers composed of α

Question 5

Desmosomes:

Accepted Answer

A) associate with actin filaments on the cytoplasmic side. 
B) contain the transmembrane proteins desmoglein and desmocollin. 
C) inhibit transfer of membrane proteins from the basolateral to the apical domain. 
D) contain integrins. 
A) associate with actin filaments on the cytoplasmic side. 
B) contain the transmembrane proteins desmoglein and desmocollin. 
C) inhibit transfer of membrane proteins from the basolateral to the apical domain. 
D) contain integrins.

Question 6

Dystroglycan is a large glycoprotein that binds to dystrophin in muscle cells.It is also present in other cells and can also bind to:

Accepted Answer

A) laminin. 
B) the virus that causes Lassa fever. 
C) the bacterium that causes leprosy. 
D) all of the above 
A) laminin. 
B) the virus that causes Lassa fever. 
C) the bacterium that causes leprosy. 
D) all of the above

Question 7

Which one of the following is NOT a property of perlecan?

Accepted Answer

A) It contains laminin-like LG domains. 
B) It is a proteoglycan. 
C) It is only found in the basal lamina. 
D) It is a glycoprotein. 
A) It contains laminin-like LG domains. 
B) It is a proteoglycan. 
C) It is only found in the basal lamina. 
D) It is a glycoprotein.

Question 8

Cadherin cellular adhesion molecules promote:

Accepted Answer

A) collagen binding. 
B) multiadhesive matrix protein binding. 
C) cell-specific homophilic interactions. 
D) all of the above 
A) collagen binding. 
B) multiadhesive matrix protein binding. 
C) cell-specific homophilic interactions. 
D) all of the above

Question 9

Cellular responses to adhesion receptor signaling do NOT include:

Accepted Answer

A) cell proliferation. 
B) cytoskeletal organization. 
C) gene transcription. 
D) all of the above 
A) cell proliferation. 
B) cytoskeletal organization. 
C) gene transcription. 
D) all of the above

Question 10

Which of the following is NOT true regarding matrix metalloproteases?

Accepted Answer

A) Their activity depends on zinc ions. 
B) They are responsible for cleaving β-catenin from E-cadherin. 
C) They are inhibited by TIMPs. 
D) Some of the members are called gelatinases. 
A) Their activity depends on zinc ions. 
B) They are responsible for cleaving β-catenin from E-cadherin. 
C) They are inhibited by TIMPs. 
D) Some of the members are called gelatinases.

Question 11

Which of the following statements best describes the difference between low-affinity integrins and high-affinity integrins?

Accepted Answer

A) Many integrins can exist in two conformations: a low-affinity (bent)conformation and a high-affinity (straight)conformation. 
B) Dissociation of the αβ heterodimer converts many integrins from the low-affinity to the high-affinity state. 
C) Association of the αβ heterodimer converts many integrins from the low-affinity to the high-affinity state. 
D) Proteolytic cleavage of the C-terminal tails of the two subunits converts many integrins from the low-affinity to the high-affinity state. 
A) Many integrins can exist in two conformations: a low-affinity (bent)conformation and a high-affinity (straight)conformation. 
B) Dissociation of the αβ heterodimer converts many integrins from the low-affinity to the high-affinity state. 
C) Association of the αβ heterodimer converts many integrins from the low-affinity to the high-affinity state. 
D) Proteolytic cleavage of the C-terminal tails of the two subunits converts many integrins from the low-affinity to the high-affinity state.

Question 12

What is the role of Ca²⁺ in NCAM-mediated homophilic cell-cell adhesion?

Accepted Answer

Ca²⁺ has no role in

Question 13

What is the function of plasmodesmata in plants?

Accepted Answer

The function of plasmodesmata is to conn

Question 14

In a classic experiment,H.V.Wilson studied aggregation of mechanically dissociated individual sponge cells from two different species.He found that the cells of each species would adhere to one another but not to cells of the other species.Describe the factors involved in this species-specific aggregation.

Accepted Answer

The sponge cells aggregate as a result o

Question 15

Which extracellular matrix component is expressed in a cell-specific manner and binds to the tripeptide sequence Arg-Gly-Asp?

Accepted Answer

A) integrins 
B) collagen 
C) proteoglycans 
D) fibronectins 
A) integrins 
B) collagen 
C) proteoglycans 
D) fibronectins

Question 16

How are multiple forms of fibronectin generated?

Accepted Answer

Multiple molecular forms of fi

Question 17

Describe the importance of extravasation and how leukocytes use this mechanism to fight infection/inflammation.

Accepted Answer

In response to signals in the areas of i

Question 18

The major families of cell surface adhesion molecules include:

Accepted Answer

A) cadherins and selectins. 
B) integrins. 
C) the Ig-superfamily. 
D) all of the above 
A) cadherins and selectins. 
B) integrins. 
C) the Ig-superfamily. 
D) all of the above

Question 19

Heparan sulfate,an example of a(n)_____________,aids in the activation of ____________.

Accepted Answer

A) GAG;FGFR 
B) proteoglycan;FGF 
C) multi-adhesive protein;FGFR 
D) integrin;cell motility 
A) GAG;FGFR 
B) proteoglycan;FGF 
C) multi-adhesive protein;FGFR 
D) integrin;cell motility

Question 20

What are the three unusually abundant amino acids in collagen?

Accepted Answer

The three unusually abundant a

Exam 19: Integrating Cells Into Tissues

EDTA is a divalent cation chelator.Propose an explanation for how EDTA promotes the dissociation of animal cell tissue?

NCAMs,a group of cell-adhesion proteins belonging to the Ig superfamily:

Pectins and hyaluronic acid are both:

What is the oligomeric structure of integrins?

Desmosomes:

Dystroglycan is a large glycoprotein that binds to dystrophin in muscle cells.It is also present in other cells and can also bind to:

Which one of the following is NOT a property of perlecan?

Cadherin cellular adhesion molecules promote:

Cellular responses to adhesion receptor signaling do NOT include:

Which of the following is NOT true regarding matrix metalloproteases?

Which of the following statements best describes the difference between low-affinity integrins and high-affinity integrins?

What is the role of Ca²⁺ in NCAM-mediated homophilic cell-cell adhesion?

What is the function of plasmodesmata in plants?

Which extracellular matrix component is expressed in a cell-specific manner and binds to the tripeptide sequence Arg-Gly-Asp?

How are multiple forms of fibronectin generated?

Describe the importance of extravasation and how leukocytes use this mechanism to fight infection/inflammation.

The major families of cell surface adhesion molecules include:

Heparan sulfate,an example of a(n)_____________,aids in the activation of ____________.

What are the three unusually abundant amino acids in collagen?

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Cell Birth, Lineage, and Death

Nerve Cells

Immunology

Cancer

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