Chapter 15 Flashcards
Caveolae are rich in cholesterol and other constituents of lipid rafts.
t/f
Defects in the human LDL receptor can cause the disease hypercholesterolemia.
t/f
Phagocytosis is an example of macropinocytosis.
t/f
The K+-glucose transporter is an example of a symport that actively transports glucose into cells.
t/f
The major ATPase maintaining the plasma membrane potential is the Na+-K+ pump.
t/f
Facilitated diffusion is a lipid-mediated process.
t/f
Estrogen is an example of a hormone to which the plasma membrane is impermeable.
t/f
The apical surface of intestinal epithelial cells is covered by a carbohydrate coat known as the glycocalyx.
t/f
The outer membrane of mitochondria is the major site where porins are found in animal cells.
t/f
Phosphatidylcholine is the only major phospholipid in the plasma membrane.
t/f
Glycolipids are the major lipids in the plasma membrane.
t/f
What is the mechanism by which cells take up specific macromolecules?
a
Where is clathrin located in cells?
a
Describe a role or function for coated pits in the process of receptor-mediated endocytosis.
a
Define endocytosis and explain the process by which it operates.
a
Explain how phagocytosis differs mechanistically from other types of endocytosis.
a
How is rapid transport of water across the plasma membrane achieved?
a
How does the structure of a transport protein such as a glucose transporter create an aqueous environment in which glucose may be transported across the plasma membrane?
aa
What is one function of cell-surface carbohydrates?
a
Frye and Edidin demonstrated the mobility of membrane proteins with the use of fused human and mouse cells. Briefly describe the results of their experiment.
a
What are peripheral membrane proteins?
a
What are integral membrane proteins?
a
Some endocytic receptors are _______ from endosomes, while others are _______ in lysosomes.
a
The cytoplasmic domain of ligand-bound LDL receptor binds to _______ proteins, which in turn associate with the _______ coat
a
Active transport can be driven by _______ hydrolysis or by _______ gradients.
a
The plasma membrane of intestinal epithelial cells is divided into two domains: the _______ domain and the _______ domain.
a
Some plasma membrane proteins are immobilized by association with proteins, other plasma membrane _______ proteins, and the _______ matrix.
a
The membrane-spanning portion of the protein porin (and proteins with similar structures in the outer membranes of mitochondria and chloroplasts) has a membrane-spanning secondary structure called a(n) _______.
a
The membrane-spanning portion of a single-pass transmembrane protein is usually a secondary structure called a(n) _______.
a
Coated pits are converted to coated vesicles by formation of rings of the protein
Question 42 options:
caveolin.
clathrin.
COPI.
dynamin.
a
Brown and Goldstein discovered the mechanism of cholesterol uptake by studying fibroblasts from patients with which disease?
Question 41 options:
Chronic fatigue syndrome
Familial hypercholesterolemia
Lupus erythematosis
Cystic fibrosis
a
Cholesterol is taken up into most cells of the body by
Question 40 options:
phagocytosis.
receptor-mediated endocytosis.
simple diffusion.
caveolae formation.
a
Phagocytosis is the main function of what two types of human white blood cells?
Question 39 options:
Macrophages and T lymphocytes
Platelets and neutrophils
Macrophages and neutrophils
Eosinophils and T lymphocytes
a
Aged red blood cells are removed from circulation by macrophages in the
Question 38 options:
bone marrow.
lymph nodes.
spleen.
kidney
a
Phagocytosis involves movement of the cell surface by
Question 37 options:
actin-based motility.
microtubule-based motility.
clathrin-based vesicle formation.
dynamin-based vesicle formation.
a
The functioning of the Na+-Ca2+ transporter in the plasma membrane is an example of
Question 36 options:
facilitated diffusion.
symport.
antiport.
endocytosis.
a
Coupled transport of glucose and Na+ into the intestinal epithelial cell is an example of
Question 35 options:
facilitated diffusion.
symport.
antiport.
endocytosis.
a
Bacteria, fungi, and plants use a gradient of _______ ions across their plasma membranes to drive transport of other molecules into the cells.
Question 34 options:
Na+
K+
H+
Ca2+
a
Calcium levels remain low in the cytosol
Question 33 options:
only to ensure that calcium does not precipitate inside the cells.
thus transient calcium increases can be used as intracellular signals.
so that calcium does not accumulate in mitochondria.
to allow extracellular calcium to drive import of other ions.
a
What percent of the ATP in a typical animal cell is consumed by the Na+-K+ pump?
Question 32 options:
1%
10%
25%
66%
a