Bio 250 Exam #2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
The tightest attachment between a cell and its extracellular matrix is seen at the site where an
epithelial cell is attached to the underlying basement membrane. The specialized adhesive
structure found at such a site is called a(n) - CORRECT ANSWER - bemidesmosome
Gorter and Grendel extracted lipids from human red blood cells. They calculated the total surface
area covered by these membrane lipids once they were spread across the surface of water and
found it to be 36 u2. How much cell surface area would be for these red blood cells? -
CORRECT ANSWER - 18 u2
What word describes a molecule that contains both hydrophilic and hydrophobic portions? -
CORRECT ANSWER - amphipathic
What word below characterizes the amino acids that are found in an a-helical segment that spans
a membrane - CORRECT ANSWER - predominantly hydrophobic
what type of cell adhesion molecule is associated with cells being held together by adherens
junctions at the site of the junction? - CORRECT ANSWER - cadherins
The loss of the cadherin function may be instrumental in what disease state? - CORRECT
ANSWER - the spread of malignant tumors
A transport system that moves one solute into the cell and another one out of the cell during a
single cycle accompanied by the expenditure of energy through ATP hydrolysis could be called
a(n) - CORRECT ANSWER - active antiport
What membrane protein family made of two transmembrane chains (a and B) is involved in
attaching cells to their extracellular microenvironment? - CORRECT ANSWER - integrins
Exam Questions and CORRECT Answers
The tightest attachment between a cell and its extracellular matrix is seen at the site where an
epithelial cell is attached to the underlying basement membrane. The specialized adhesive
structure found at such a site is called a(n) - CORRECT ANSWER - bemidesmosome
Gorter and Grendel extracted lipids from human red blood cells. They calculated the total surface
area covered by these membrane lipids once they were spread across the surface of water and
found it to be 36 u2. How much cell surface area would be for these red blood cells? -
CORRECT ANSWER - 18 u2
What word describes a molecule that contains both hydrophilic and hydrophobic portions? -
CORRECT ANSWER - amphipathic
What word below characterizes the amino acids that are found in an a-helical segment that spans
a membrane - CORRECT ANSWER - predominantly hydrophobic
what type of cell adhesion molecule is associated with cells being held together by adherens
junctions at the site of the junction? - CORRECT ANSWER - cadherins
The loss of the cadherin function may be instrumental in what disease state? - CORRECT
ANSWER - the spread of malignant tumors
A transport system that moves one solute into the cell and another one out of the cell during a
single cycle accompanied by the expenditure of energy through ATP hydrolysis could be called
a(n) - CORRECT ANSWER - active antiport
What membrane protein family made of two transmembrane chains (a and B) is involved in
attaching cells to their extracellular microenvironment? - CORRECT ANSWER - integrins
