Question 1

The movement of water across a membrane from an area of lower solute concentration to a region of higher solute concentration is called ____.

Accepted Answer

A)  osmosis only 
B)  active transport only 
C)  endocytosis only 
D)  both diffusion and osmosis 
E)  both osmosis and active transport 
A)  osmosis only 
B)  active transport only 
C)  endocytosis only 
D)  both diffusion and osmosis 
E)  both osmosis and active transport

Question 2

Explain why the transport of molecules across the cell membrane is considered to be both specific and directional.

Accepted Answer

Transport is considered directional beca

Question 3

The Na+/K+pump creates a ____ charge inside the cell and a ____ charge outside the cell.

Accepted Answer

A)  negative; negative 
B)  positive; negative 
C)  positive; positive 
D)  negative; positive 
E)  neutral; positive 
A)  negative; negative 
B)  positive; negative 
C)  positive; positive 
D)  negative; positive 
E)  neutral; positive

Question 4

The major structural components of a cell membrane are ____.

Accepted Answer

A)  phospholipids and cellulose 
B)  phospholipids, protein, and sterols 
C)  protein and sterols 
D)  glycolipids and proteins 
E)  phospholipids and glycolipids 
A)  phospholipids and cellulose 
B)  phospholipids, protein, and sterols 
C)  protein and sterols 
D)  glycolipids and proteins 
E)  phospholipids and glycolipids

Question 5

Which type of lipid is most important to the structure of biological membranes?

Accepted Answer

A)  fat 
B)  wax 
C)  phospholipid 
D)  neutral fat 
E)  triglyceride 
A)  fat 
B)  wax 
C)  phospholipid 
D)  neutral fat 
E)  triglyceride

Question 6

Cells undergo exocytosis ____.

Accepted Answer

A)  to pump protons down a concentration gradient 
B)  when replicating 
C)  to secrete protein and wastes from the cell 
D)  to ingest nutrients 
E)  as a means of cellular protection 
A)  to pump protons down a concentration gradient 
B)  when replicating 
C)  to secrete protein and wastes from the cell 
D)  to ingest nutrients 
E)  as a means of cellular protection

Question 7

Polar and charged molecules typically cross the cell membrane by way of ____.

Accepted Answer

A)  simple diffusion 
B)  osmosis 
C)  filtration 
D)  active transport 
E)  facilitated diffusion 
A)  simple diffusion 
B)  osmosis 
C)  filtration 
D)  active transport 
E)  facilitated diffusion

Question 8

When referring to membrane glycolipids and glycoproteins, the term "glyco-" indicates ____.

Accepted Answer

A)  carbohydrate groups are attached to the molecules 
B)  the molecules are bound to the glycocalyx 
C)  the molecules are found on both the interior and exterior of the membrane 
D)  the molecules are attached to the membrane by ionic bonds 
E)  the molecules are rarely found on the membrane exterior 
A)  carbohydrate groups are attached to the molecules 
B)  the molecules are bound to the glycocalyx 
C)  the molecules are found on both the interior and exterior of the membrane 
D)  the molecules are attached to the membrane by ionic bonds 
E)  the molecules are rarely found on the membrane exterior

Question 9

Cholesterol is essential for keeping cell membranes from thickening .

Accepted Answer

A) True 
 B)False

Question 10

The selective permeability of a membrane refers to the ____.

Accepted Answer

A)  movement of a molecule from an area of high concentration to an area of low concentration 
B)  ability of a substance to pass through any membrane 
C)  ability of only certain molecules to pass across a membrane 
D)  need for carrier proteins to transport some molecules across a membrane 
E)  ability of molecules to be transported across a membrane 
A)  movement of a molecule from an area of high concentration to an area of low concentration 
B)  ability of a substance to pass through any membrane 
C)  ability of only certain molecules to pass across a membrane 
D)  need for carrier proteins to transport some molecules across a membrane 
E)  ability of molecules to be transported across a membrane

Question 11

Which molecules demonstrate dual solubility characteristics?

Accepted Answer

A)  sterols only 
B)  proteins only 
C)  phospholipids only 
D)  sterols and phospholipids 
E)  sterols, phospholipids, and proteins 
A)  sterols only 
B)  proteins only 
C)  phospholipids only 
D)  sterols and phospholipids 
E)  sterols, phospholipids, and proteins

Question 12

Which adaptation to the plasma membrane allows mammals to hibernate in subzero temperatures without their plasma membranes freezing?

Accepted Answer

A)  increase in cholesterol content only 
B)  increase in protein content only 
C)  increase in the number of double covalent bonds in phospholipids 
D)  increase in both cholesterol and protein content 
E)  increase in both cholesterol and double covalent bonds in phospholipids 
A)  increase in cholesterol content only 
B)  increase in protein content only 
C)  increase in the number of double covalent bonds in phospholipids 
D)  increase in both cholesterol and protein content 
E)  increase in both cholesterol and double covalent bonds in phospholipids

Question 13

The Na+/K+pump transports ____.

Accepted Answer

A)  two sodium ions in and two potassium ions out 
B)  two sodium ions in and three potassium ions out 
C)  two sodium ions out and three potassium ions in 
D)  three sodium ions in and two potassium ions out 
E)  three sodium ions out and two potassium ions in 
A)  two sodium ions in and two potassium ions out 
B)  two sodium ions in and three potassium ions out 
C)  two sodium ions out and three potassium ions in 
D)  three sodium ions in and two potassium ions out 
E)  three sodium ions out and two potassium ions in

Question 14

In receptor-mediated endocytosis, the receptors collect into a depression called a coated pit for endocytosis after the target molecules bind to them.

Accepted Answer

A) True 
 B)False

Question 15

Which function of cellular membranes is critical to the molecular organization of cells?

Accepted Answer

A)  the controlled transport of ions and molecules across the membrane 
B)  cell-cell binding 
C)  recognition of other cells as being "foreign" or "self" 
D)  reception of chemical signals from other cells 
E)  participation in metabolic reactions 
A)  the controlled transport of ions and molecules across the membrane 
B)  cell-cell binding 
C)  recognition of other cells as being "foreign" or "self" 
D)  reception of chemical signals from other cells 
E)  participation in metabolic reactions

Question 16

A transport system in which the transport of an ion in one direction provides the energy for active transport in the opposite direction is known as ____.

Accepted Answer

A)  antiport 
B)  active diffusion 
C)  symport 
D)  facilitated diffusion 
E)  osmosis 
A)  antiport 
B)  active diffusion 
C)  symport 
D)  facilitated diffusion 
E)  osmosis

Question 17

In what way do the various membranes of a cell differ?

Accepted Answer

A)  Phospholipids are found only in certain membranes. 
B)  Certain proteins are unique to each membrane. 
C)  Only certain membranes are constructed from molecules with dual solubility. 
D)  Only certain membranes of a cell are selectively permeable. 
E)  Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm. 
A)  Phospholipids are found only in certain membranes. 
B)  Certain proteins are unique to each membrane. 
C)  Only certain membranes are constructed from molecules with dual solubility. 
D)  Only certain membranes of a cell are selectively permeable. 
E)  Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.

Question 18

As part of an experiment, researchers grew several different types of cells in the presence of radioactive iodine. After some time had passed, the cells were washed, and the levels of iodine inside the cell were determined. What is the most plausible explanation for why some cells had higher levels of radioactivity after treatment than others?

Accepted Answer

A)  Cells that had high radioactivity levels after treatment contain iodine transporters. 
B)  Cells that had high radioactivity levels after treatment lack iodine transporters. 
C)  Cells that had high radioactivity levels after treatment had a mutation in genes encoding iodine transporter proteins. 
D)  Cells that had high radioactivity levels after treatment lack clathrin. 
E)  Cells that had high radioactivity levels after treatment lack lysosomes. 
A)  Cells that had high radioactivity levels after treatment contain iodine transporters. 
B)  Cells that had high radioactivity levels after treatment lack iodine transporters. 
C)  Cells that had high radioactivity levels after treatment had a mutation in genes encoding iodine transporter proteins. 
D)  Cells that had high radioactivity levels after treatment lack clathrin. 
E)  Cells that had high radioactivity levels after treatment lack lysosomes.

Question 19

In secondary active transport, when both the driving ion and the transport ion are in high concentration outside of the cell, in which direction will the two ions move?

Accepted Answer

A)  As the driving ion moves in, the transport ion moves in. 
B)  As the driving ion moves in, the transport ion moves out. 
C)  As the driving ion moves out, the transport ion moves in. 
D)  As the driving ion moves out, the transport ion moves out. 
E)  As long as both ions are moving together, they can go either in or out. 
A)  As the driving ion moves in, the transport ion moves in. 
B)  As the driving ion moves in, the transport ion moves out. 
C)  As the driving ion moves out, the transport ion moves in. 
D)  As the driving ion moves out, the transport ion moves out. 
E)  As long as both ions are moving together, they can go either in or out.

Question 20

Describe the steps involved in the functioning of the Na+/K+pump, including the order and cellular localization of the binding of the ions, as well as how the transporter works.

Accepted Answer

First, three sodium ions in the cytosol

Exam 5: Membranes and Transport

The movement of water across a membrane from an area of lower solute concentration to a region of higher solute concentration is called ____.

Explain why the transport of molecules across the cell membrane is considered to be both specific and directional.

The Na+/K+pump creates a ____ charge inside the cell and a ____ charge outside the cell.

The major structural components of a cell membrane are ____.

Which type of lipid is most important to the structure of biological membranes?

Cells undergo exocytosis ____.

Polar and charged molecules typically cross the cell membrane by way of ____.

When referring to membrane glycolipids and glycoproteins, the term "glyco-" indicates ____.

Cholesterol is essential for keeping cell membranes from thickening .

The selective permeability of a membrane refers to the ____.

Which molecules demonstrate dual solubility characteristics?

Which adaptation to the plasma membrane allows mammals to hibernate in subzero temperatures without their plasma membranes freezing?

The Na+/K+pump transports ____.

In receptor-mediated endocytosis, the receptors collect into a depression called a coated pit for endocytosis after the target molecules bind to them.

Which function of cellular membranes is critical to the molecular organization of cells?

A transport system in which the transport of an ion in one direction provides the energy for active transport in the opposite direction is known as ____.

In what way do the various membranes of a cell differ?

In secondary active transport, when both the driving ion and the transport ion are in high concentration outside of the cell, in which direction will the two ions move?

Describe the steps involved in the functioning of the Na+/K+pump, including the order and cellular localization of the binding of the ions, as well as how the transporter works.

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Energy, Enzymes, and Biological Reactions

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Regulation of Gene Expression

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

The Origin of Life

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

The Na⁺/K⁺pump creates a charge inside the cell and a charge outside the cell.

The Na⁺/K⁺pump transports ____.

Describe the steps involved in the functioning of the Na⁺/K⁺pump, including the order and cellular localization of the binding of the ions, as well as how the transporter works.