Chapter 7

Last update by Babara on 09/08/2014
960426 People have viewed this Quiz
  • Share

Which of the following is one of the ways that the membranes of winter wheat are able toremain fluid when it is extremely cold?

A) by increasing the percentage of unsaturated phospholipids in the membrane

B) by increasing the percentage of cholesterol molecules in the membrane

C) by decreasing the number of hydrophobic proteins in the membrane

D) by co-transport of glucose and hydrogen

E) by using active transport



Answer:

A) by increasing the percentage of unsaturated phospholipids in the membrane



View Chapter 7 as Flashcard Deck

Related Quiz Content
  • feldman2009
    Answered in Chapter 7

    Which of the following statements is correct about diffusion?

    A) It is very rapid over long distances.

    B) It requires an expenditure of energy bythe cell.

    C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

    D) It is an active process in which molecules move from a region of lower concentration to one of higher concentration.

    E) It requires integral proteins in the cell membrane.

    C) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
  • feldman2009
    Answered in Chapter 7

    In order for a protein to be an integral membrane protein it would have to be which of the following? 

    A) hydrophilic 

    B) hydrophobic 

    C) amphipathic 

    D) completely covered with phospholipids 

    E) exposed on only one surface of the membrane 

    C) amphipathic 



  • feldman2009
    Answered in Chapter 7

    When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are 

    A) peripheral proteins. 

    B) phospholipids. 

    C) carbohydrates. 

    D) integral proteins. 

    E) cholesterol molecules.

    D) integral proteins. 



  • feldman2009
    Answered in Chapter 7

     Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? 

    A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. 

    B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. 

    C) Unsaturated fatty acids permit more water in the interior of the membrane. 

    D) The double bonds block interaction among the hydrophilic head groups of the lipids. 

    E) The double bonds result in shorter fatty acid tails and thinner membranes. 



    A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. 



  • feldman2009
    Answered in Chapter 7

    Which of the following is true of integral membrane proteins? 

    A) They lack tertiary structure. 

    B) They are loosely bound to the surface of the bilayer.

    C) They are usually transmembrane proteins. 

    D) They are not mobile within the bilayer. 

    E) They serve only a structural role in membranes.

    C) They are usually transmembrane proteins. 



  • feldman2009
    Answered in Chapter 7

    Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? 

    A) facilitated diffusion of molecules down their concentration gradients 

    B) active transport of molecules against their concentration gradients 

    C) maintaining the integrity of a fluid mosaic membrane 

    D) maintaining membrane fluidity at low temperatures 

    E) a cell's ability to distinguish one type of neighboring cell from another 



    E) a cell's ability to distinguish one type of neighboring cell from another 



  • feldman2009
    Answered in Chapter 7

    An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function? 

    A) transporting ions against an electrochemical gradient 

    B) cell-cell recognition 

    C) maintaining fluidity of the phospholipid bilayer 

    D) attaching to the cytoskeleton 

    E) establishing the diffusion barrier to charged molecules 



    B) cell-cell recognition 



  • feldman2009
    Answered in Chapter 7

    In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model? 

    A) The membrane is only fluid across a very narrow temperature range. 

    B) Proteins rarely move, even though they possibly can do so. 

    C) Unsaturated lipids are excluded from the membranes. 

    D) The concentration of protein molecules is now known to be much higher. 

    E) The proteins are known to be made of only acidic amino acids. 



    D) The concentration of protein molecules is now known to be much higher. 



  • feldman2009
    Answered in Chapter 7

    Which of the following span the phospholipids bilayer, usually a number of times?

    A) transmembrane proteins

    B) integral proteins

    C) peripheral proteins

    D) integrins

    E) glycoproteins



    A) transmembrane proteins



  • feldman2009
    Answered in Chapter 7

    Which of these are not embedded in the lipid bilayer at all? 

    A) transmembrane proteins 

    B) integral proteins 

    C) peripheral proteins 

    D) integrins 

    E) glycoproteins 



    C) peripheral proteins