Question 1

Lipid bilayers differ from micelles in that micelles are:

Accepted Answer

A)  self limiting structures. 
B)  formed spontaneously. 
C)  stable in aqueous solution. 
D)  often transformed into vesicles. 
E)  all are true. 
A)  self limiting structures. 
B)  formed spontaneously. 
C)  stable in aqueous solution. 
D)  often transformed into vesicles. 
E)  all are true.

Question 2

Flippases are enzymes that flip:

Accepted Answer

A)  fatty acids from one position on glycerol to another position. 
B)  glucose from α- to β-glucose. 
C)  amino acids from one position to another in a protein. 
D)  cholesterol from one organelle to another. 
E)  phospholipids across to the other side of a membrane. 
A)  fatty acids from one position on glycerol to another position. 
B)  glucose from α- to β-glucose. 
C)  amino acids from one position to another in a protein. 
D)  cholesterol from one organelle to another. 
E)  phospholipids across to the other side of a membrane.

Question 3

In a typical Na+,K+-ATPase, _____ sodium ions are moved from the _____ of the cell while _____ potassium ions are moved from the _____ of the cell

Accepted Answer

A)  2; inside to outside; 3; outside to inside 
B)  3; inside to outside; 2; outside to inside 
C)  2; outside to inside; 3; inside to outside 
D)  3; outside to inside; 2; inside to outside 
E)  none of the above 
A)  2; inside to outside; 3; outside to inside 
B)  3; inside to outside; 2; outside to inside 
C)  2; outside to inside; 3; inside to outside 
D)  3; outside to inside; 2; inside to outside 
E)  none of the above

Question 4

Discuss ClC channels.​

Accepted Answer

The ClC channels (ubiquitous in cells fr

Question 5

All are true for phase transitions of lipid bilayers EXCEPT:

Accepted Answer

A)  the transitions are exothermic. 
B)  particular phospholipids display characteristic transition temperatures. 
C)  pure phospholipid bilayers have narrow transition ranges. 
D)  volume changes usually are associated with phase transitions. 
E)  solutes interacting with membrane lipids affect transition temperatures. 
A)  the transitions are exothermic. 
B)  particular phospholipids display characteristic transition temperatures. 
C)  pure phospholipid bilayers have narrow transition ranges. 
D)  volume changes usually are associated with phase transitions. 
E)  solutes interacting with membrane lipids affect transition temperatures.

Question 6

All are characteristic of the gastric proton pump EXCEPT:

Accepted Answer

A)  Gastric proton pump requires high levels of dietary K+ to create a K+ gradient. 
B)  Gastric proton pump is a H+, K+-ATPase. 
C)  Gastric proton pump maintains a pH gradient of about 6.6 across the mucosal cell membrane. 
D)  Gastric proton pump is electroneutral. 
E)  Gastric proton pump produces a net influx of HCl into the stomach. 
A)  Gastric proton pump requires high levels of dietary K+ to create a K+ gradient. 
B)  Gastric proton pump is a H+, K+-ATPase. 
C)  Gastric proton pump maintains a pH gradient of about 6.6 across the mucosal cell membrane. 
D)  Gastric proton pump is electroneutral. 
E)  Gastric proton pump produces a net influx of HCl into the stomach.

Question 7

Explain the formation of thioether-linked prenyl anchor proteins.​

Accepted Answer

Prenylation of proteins destined for mem

Question 8

The transport of glutamine across a membrane was measured, and the results obtained are presented in the following table. What type of transport does Gln exhibit?

Accepted Answer

A)  primary active transport 
B)  secondary active transport 
C)  passive diffusion 
D)  facilitated diffusion 
E)  cannot determine from the given data 
A)  primary active transport 
B)  secondary active transport 
C)  passive diffusion 
D)  facilitated diffusion 
E)  cannot determine from the given data

Question 9

Active transport is uniquely characterized by:

Accepted Answer

A)  transport of hydrophobic molecules. 
B)  transport of hydrophilic molecules. 
C)  transport of a molecule or ion across a membrane, with the species going from a greater concentration to a lesser concentration. 
D)  the tight coupling of an input of energy to drive a thermodynamically unfavorable reaction. 
E)  absolute requirement for ATP hydrolysis, and light energy or ion gradient energy will not work. 
A)  transport of hydrophobic molecules. 
B)  transport of hydrophilic molecules. 
C)  transport of a molecule or ion across a membrane, with the species going from a greater concentration to a lesser concentration. 
D)  the tight coupling of an input of energy to drive a thermodynamically unfavorable reaction. 
E)  absolute requirement for ATP hydrolysis, and light energy or ion gradient energy will not work.

Question 10

Muscle Ca2+-ATPase resembles Na+, K+-ATPase in many ways EXCEPT:

Accepted Answer

A)  Both have α-subunits of similar size. 
B)  Both form covalent E-P intermediates during ATP hydrolysis. 
C)  Both have similar mechanisms of ATP hydrolysis. 
D)  Both have similar ion transport mechanisms. 
E)  Both have residence on the sarcoplasmic reticulum. 
A)  Both have α-subunits of similar size. 
B)  Both form covalent E-P intermediates during ATP hydrolysis. 
C)  Both have similar mechanisms of ATP hydrolysis. 
D)  Both have similar ion transport mechanisms. 
E)  Both have residence on the sarcoplasmic reticulum.

Question 11

People with high blood pressure have high blood levels of an endogenous Na+, K+-ATPase ____ that results in ____ of sodium and calcium in cells lining the blood vessel wall.

Accepted Answer

A)  inhibitor; decrease 
B)  stimulator, decrease 
C)  inhibitor; accumulation 
D)  stimulator; accumulation 
E)  none of the above 
A)  inhibitor; decrease 
B)  stimulator, decrease 
C)  inhibitor; accumulation 
D)  stimulator; accumulation 
E)  none of the above

Question 12

G protein-α-subunits are anchored into membranes by:

Accepted Answer

A)  amine-linked myristoyl anchors. 
B)  thioester-linked fatty acyl anchors. 
C)  amide-linked prenyl anchors. 
D)  thioester-linked prenyl anchors. 
E)  amide-linked glycosyl phosphatidylinositol anchors. 
A)  amine-linked myristoyl anchors. 
B)  thioester-linked fatty acyl anchors. 
C)  amide-linked prenyl anchors. 
D)  thioester-linked prenyl anchors. 
E)  amide-linked glycosyl phosphatidylinositol anchors.

Question 13

Explain the structure of caveolae.​

Accepted Answer

Caveolae are flask-shaped indentations i

Question 14

Nearly all of the calcium ions in muscle are sequestered inside vesicles called:

Accepted Answer

A)  mitochondria. 
B)  sarcoplasmic reticulum. 
C)  endoplasmic reticulum. 
D)  Golgi. 
E)  secretory vesicles. 
A)  mitochondria. 
B)  sarcoplasmic reticulum. 
C)  endoplasmic reticulum. 
D)  Golgi. 
E)  secretory vesicles.

Question 15

The plasma membrane is responsible for all EXCEPT:

Accepted Answer

A)  energy transduction. 
B)  exclusion of certain toxic ions and molecules. 
C)  signal transduction. 
D)  accumulation of cell nutrients. 
E)  all are true. 
A)  energy transduction. 
B)  exclusion of certain toxic ions and molecules. 
C)  signal transduction. 
D)  accumulation of cell nutrients. 
E)  all are true.

Question 16

Secondary active transport across a membrane refers to

Accepted Answer

A)  Movement of a molecule across a membrane and against its concentration gradient powered by an ion gradient that is created by a different transporter 
B)  Movement of a molecule across a membrane and against its concentration gradient through a transporter that is directly powered by ATP hydrolysis 
C)  Movement of a molecule across a membrane powered by its own concentration gradient 
D)  Movement of a molecule across a membrane through a transporter that has an alpha-helical secondary structure. 
E)  none of the above 
A)  Movement of a molecule across a membrane and against its concentration gradient powered by an ion gradient that is created by a different transporter 
B)  Movement of a molecule across a membrane and against its concentration gradient through a transporter that is directly powered by ATP hydrolysis 
C)  Movement of a molecule across a membrane powered by its own concentration gradient 
D)  Movement of a molecule across a membrane through a transporter that has an alpha-helical secondary structure. 
E)  none of the above

Question 17

When we say that biological membranes are asymmetric structures we mean that:

Accepted Answer

A)  The lipids are not evenly distributed transversely in the membrane. 
B)  The proteins are not evenly distributed over the surface of the membrane. 
C)  Patches of cholesterol and other lipids occur on the surface of the membrane. 
D)  Certain membrane proteins seem to prefer association with specific lipids. 
E)  All are true 
A)  The lipids are not evenly distributed transversely in the membrane. 
B)  The proteins are not evenly distributed over the surface of the membrane. 
C)  Patches of cholesterol and other lipids occur on the surface of the membrane. 
D)  Certain membrane proteins seem to prefer association with specific lipids. 
E)  All are true

Question 18

H+-transporting ATPases found in ____ break down bone during normal bone remodeling are of the ____ type of ATPases.

Accepted Answer

A)  osteoclasts; vacuolar (V-) 
B)  osteoclast; H+, K+-ATPase 
C)  osteoblast; H+, K+-ATPase 
D)  osteoblast; vacuolar (V-) 
E)  osteoclast; Na+, K+-ATPase 
A)  osteoclasts; vacuolar (V-) 
B)  osteoclast; H+, K+-ATPase 
C)  osteoblast; H+, K+-ATPase 
D)  osteoblast; vacuolar (V-) 
E)  osteoclast; Na+, K+-ATPase

Question 19

Discuss the preferred locations of different amino acids in transmembrane proteins.​

Accepted Answer

Hydrophobic amino acids (alanine, valine

Question 20

Hydropathy plots for transport proteins are utilized to reveal:

Accepted Answer

A)  amino acid residues which may be highly modified. 
B)  amino acid residues which may be directly involved in facilitated transport. 
C)  stretches of amino acid residues that make up hydrophobic regions, which may be directly associated with the lipid bilayer. 
D)  amino acid residues which are hyper-reactive due to their location. 
E)  whether there is interaction between N-terminal and C-terminal amino acids. 
A)  amino acid residues which may be highly modified. 
B)  amino acid residues which may be directly involved in facilitated transport. 
C)  stretches of amino acid residues that make up hydrophobic regions, which may be directly associated with the lipid bilayer. 
D)  amino acid residues which are hyper-reactive due to their location. 
E)  whether there is interaction between N-terminal and C-terminal amino acids.

Exam 9: Membranes and Membrane Transport

Lipid bilayers differ from micelles in that micelles are:

Flippases are enzymes that flip:

In a typical Na+,K+-ATPase, _____ sodium ions are moved from the _____ of the cell while _____ potassium ions are moved from the _____ of the cell

Discuss ClC channels.​

All are true for phase transitions of lipid bilayers EXCEPT:

All are characteristic of the gastric proton pump EXCEPT:

Explain the formation of thioether-linked prenyl anchor proteins.​

The transport of glutamine across a membrane was measured, and the results obtained are presented in the following table. What type of transport does Gln exhibit?

Active transport is uniquely characterized by:

Muscle Ca2+-ATPase resembles Na+, K+-ATPase in many ways EXCEPT:

People with high blood pressure have high blood levels of an endogenous Na+, K+-ATPase ____ that results in ____ of sodium and calcium in cells lining the blood vessel wall.

G protein-α-subunits are anchored into membranes by:

Explain the structure of caveolae.​

Nearly all of the calcium ions in muscle are sequestered inside vesicles called:

The plasma membrane is responsible for all EXCEPT:

Secondary active transport across a membrane refers to

When we say that biological membranes are asymmetric structures we mean that:

H+-transporting ATPases found in ____ break down bone during normal bone remodeling are of the ____ type of ATPases.

Discuss the preferred locations of different amino acids in transmembrane proteins.​

Hydropathy plots for transport proteins are utilized to reveal:

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

The Reception and Transmission of Extracellular Information

Filters

In a typical Na⁺,K⁺-ATPase, ___ sodium ions are moved from the _ of the cell while _ potassium ions are moved from the ___ of the cell

Discuss ClC channels.

Explain the formation of thioether-linked prenyl anchor proteins.

Muscle Ca²⁺-ATPase resembles Na⁺, K⁺-ATPase in many ways EXCEPT:

People with high blood pressure have high blood levels of an endogenous Na⁺, K⁺-ATPase that results in of sodium and calcium in cells lining the blood vessel wall.

Explain the structure of caveolae.

H⁺-transporting ATPases found in break down bone during normal bone remodeling are of the type of ATPases.

Discuss the preferred locations of different amino acids in transmembrane proteins.