Question 1

A solution of 65% water, 35% solute is more concentrated with respect to solute than a solution of 70% water, 30% solute.

Accepted Answer

A) True 
 B)False  True

Question 2

Carrier proteins share several characteristics with enzymes used to catalyze metabolic reactions. In what ways are carrier proteins and enzymes similar?

Accepted Answer

Both carrier proteins and enzymes are specific; carrier proteins bind and transport only molecules that specifically fit the binding site, while enzymes react only with molecules that snugly fit the enzyme active site. Both carrier proteins and enzymes can become saturated when there are more molecules than proteins to interact with.

Question 3

Cells must constantly bring in certain molecules and ions while keeping others out. What part of the cell accomplishes this function?

Accepted Answer

A) the vesicles 
B) the plasma membrane 
C) the nucleus 
D) the lysosomes 
A) the vesicles 
B) the plasma membrane 
C) the nucleus 
D) the lysosomes B

Question 4

How are peripheral and transmembrane proteins different?

Accepted Answer

A) Transmembrane proteins are primarily nonpolar, while peripheral proteins are polar. 
B) Transmembrane proteins are primarily nonpolar, while peripheral proteins are a mixture of polar and nonpolar amino acids. 
C) Transmembrane proteins are primarily polar, while peripheral proteins are nonpolar. 
D) Transmembrane proteins are a mixture of polar and nonpolar amino acids, while peripheral proteins are primarily nonpolar. 
A) Transmembrane proteins are primarily nonpolar, while peripheral proteins are polar. 
B) Transmembrane proteins are primarily nonpolar, while peripheral proteins are a mixture of polar and nonpolar amino acids. 
C) Transmembrane proteins are primarily polar, while peripheral proteins are nonpolar. 
D) Transmembrane proteins are a mixture of polar and nonpolar amino acids, while peripheral proteins are primarily nonpolar.

Question 5

Identify the structures indicated in this drawing of a typical plasma membrane.  
-microfilament

Accepted Answer

The answer of Identify the structures indicated in this drawing...

Question 6

Unsaturated fatty acids cause a membrane to be fluid at lower temperatures. What is a reasonable explanation for this?

Accepted Answer

A) Unsaturated fatty acids permit more water into the interior of the membrane. 
B) The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be spaced farther apart. 
C) The double bonds in the unsaturated fatty acids block interaction among the hydrophilic head groups of the lipids. 
D) Unsaturated fatty acids have a higher cholesterol content. 
A) Unsaturated fatty acids permit more water into the interior of the membrane. 
B) The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be spaced farther apart. 
C) The double bonds in the unsaturated fatty acids block interaction among the hydrophilic head groups of the lipids. 
D) Unsaturated fatty acids have a higher cholesterol content.

Question 7

What do we mean when we say that facilitated diffusion is specific?

Accepted Answer

A) A protein will transport specific molecules. 
B) One specific integral protein per membrane is involved in facilitated diffusion. 
C) Only specific hydrophobic molecules can be transported. 
D) The energy molecule ATP is specifically required for transport. 
A) A protein will transport specific molecules. 
B) One specific integral protein per membrane is involved in facilitated diffusion. 
C) Only specific hydrophobic molecules can be transported. 
D) The energy molecule ATP is specifically required for transport.

Question 8

Match each mechanism of cellular transport with its correct definition.
-facilitated diffusion

Accepted Answer

A) movement of a molecule from an area of high concentration to an area of lower concentration 
B) cells internalize molecules into a cell by the inward budding of vesicles possessing receptors specific to the molecule being transported 
C) movement of water from a hypotonic solution into a hypertonic solution across a selectively permeable membrane 
D) large particles are enveloped by the cell membrane and internalized 
E) a process in which liquid droplets are ingested by living cells
F)diffusion of molecules across the plasma membrane with the assistance of transport proteins 
A) movement of a molecule from an area of high concentration to an area of lower concentration 
B) cells internalize molecules into a cell by the inward budding of vesicles possessing receptors specific to the molecule being transported 
C) movement of water from a hypotonic solution into a hypertonic solution across a selectively permeable membrane 
D) large particles are enveloped by the cell membrane and internalized 
E) a process in which liquid droplets are ingested by living cells
F)diffusion of molecules across the plasma membrane with the assistance of transport proteins

Question 9

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 10

What does the "mosaic" part of the fluid mosaic model refer to?

Accepted Answer

A) the membrane cholesterol 
B) the membrane functions 
C) the membrane proteins 
D) the membrane phospholipids 
A) the membrane cholesterol 
B) the membrane functions 
C) the membrane proteins 
D) the membrane phospholipids

Question 11

Identify the structures indicated in this drawing of a typical plasma membrane.  
-carbohydrate groups

Accepted Answer

The answer of Identify the structures indicated in this drawing...

Question 12

Suppose a drop of food colouring is placed in a container of clear water. What happens to the coloured dye molecules?

Accepted Answer

A) They undergo osmosis at the top of the container. 
B) They diffuse to the top of the container. 
C) They undergo osmosis equally throughout the container. 
D) They diffuse equally throughout the container. 
A) They undergo osmosis at the top of the container. 
B) They diffuse to the top of the container. 
C) They undergo osmosis equally throughout the container. 
D) They diffuse equally throughout the container.

Question 13

What does the cell wall do when a plant cell is placed in a hypotonic solution?

Accepted Answer

A) It prevents diffusion. 
B) It prevents plasmolysis. 
C) It prevents the cell from bursting. 
D) It prevents active transport. 
A) It prevents diffusion. 
B) It prevents plasmolysis. 
C) It prevents the cell from bursting. 
D) It prevents active transport.

Question 14

Which of the following is responsible for maintaining the membrane potential?

Accepted Answer

A) the Na+/K+ pump 
B) the diffusion gradient 
C) the Ca2+ pump 
D) the H+ pump 
A) the Na+/K+ pump 
B) the diffusion gradient 
C) the Ca2+ pump 
D) the H+ pump

Question 15

How are simple diffusion and facilitated diffusion similar to each other?

Accepted Answer

A) They both belong to active transport. 
B) They both transport through the aid of a transport molecule. 
C) They both require energy. 
D) They both belong to passive transport. 
A) They both belong to active transport. 
B) They both transport through the aid of a transport molecule. 
C) They both require energy. 
D) They both belong to passive transport.

Question 16

A water concentration gradient is influenced by the number of solute molecules present on both sides of the membrane.

Accepted Answer

A) True 
 B)False

Question 17

How are simple diffusion and facilitated diffusion different?

Accepted Answer

A) Facilitated diffusion is passive transport, while simple diffusion is not. 
B) Facilitated diffusion requires a transport protein, while simple diffusion does not. 
C) Simple diffusion requires a transport protein, while facilitated diffusion does not. 
D) Simple diffusion is passive transport, while facilitated diffusion is not. 
A) Facilitated diffusion is passive transport, while simple diffusion is not. 
B) Facilitated diffusion requires a transport protein, while simple diffusion does not. 
C) Simple diffusion requires a transport protein, while facilitated diffusion does not. 
D) Simple diffusion is passive transport, while facilitated diffusion is not.

Question 18

How are facilitated diffusion and active transport different from each other?

Accepted Answer

A) Active transport requires a transport protein, while facilitated diffusion does not. 
B) Facilitated diffusion requires a transport protein, while active transport does not. 
C) Facilitated diffusion occurs against the gradient, while active transport does not. 
D) Active transport occurs against the gradient, while facilitated diffusion does not. 
A) Active transport requires a transport protein, while facilitated diffusion does not. 
B) Facilitated diffusion requires a transport protein, while active transport does not. 
C) Facilitated diffusion occurs against the gradient, while active transport does not. 
D) Active transport occurs against the gradient, while facilitated diffusion does not.

Question 19

Water is a strongly polar molecule, so how does it cross the plasma membrane?

Accepted Answer

Water molecules are small enough to slip

Question 20

An unknown cell contains cholesterol. What type of cell is it most likely to be?

Accepted Answer

A) a bacterial cell 
B) a fungal cell 
C) a plant cell 
D) an animal cell 
A) a bacterial cell 
B) a fungal cell 
C) a plant cell 
D) an animal cell

Exam 5: Cell Membranes and Signalling

A solution of 65% water, 35% solute is more concentrated with respect to solute than a solution of 70% water, 30% solute.

Carrier proteins share several characteristics with enzymes used to catalyze metabolic reactions. In what ways are carrier proteins and enzymes similar?

Cells must constantly bring in certain molecules and ions while keeping others out. What part of the cell accomplishes this function?

How are peripheral and transmembrane proteins different?

Identify the structures indicated in this drawing of a typical plasma membrane. -microfilament

Unsaturated fatty acids cause a membrane to be fluid at lower temperatures. What is a reasonable explanation for this?

What do we mean when we say that facilitated diffusion is specific?

Match each mechanism of cellular transport with its correct definition. -facilitated diffusion

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

What does the "mosaic" part of the fluid mosaic model refer to?

Identify the structures indicated in this drawing of a typical plasma membrane. -carbohydrate groups

Suppose a drop of food colouring is placed in a container of clear water. What happens to the coloured dye molecules?

What does the cell wall do when a plant cell is placed in a hypotonic solution?

Which of the following is responsible for maintaining the membrane potential?

How are simple diffusion and facilitated diffusion similar to each other?

A water concentration gradient is influenced by the number of solute molecules present on both sides of the membrane.

How are simple diffusion and facilitated diffusion different?

How are facilitated diffusion and active transport different from each other?

Water is a strongly polar molecule, so how does it cross the plasma membrane?

An unknown cell contains cholesterol. What type of cell is it most likely to be?

Light and Life

The Cell: an Overview

Defining Life and Its Origins

Energy and Enzymes

Cellular Respiration

Photosynthesis

Cell Cycles

Genetic Recombination

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Structure and Expression

Control of Gene Expression

Dna Technologies

Genomes and Proteomes

Evolution: the Development of the Theory

Microevolution: Changes Within Populations

Species and Macroevolution

Understanding the History of Life on Earth

Humans and Evolution

Bacteria and Archaea

Viruses, Viroids, and Prions: Infectious Biological Particles

Protists

Fungi

Plants

Diversity of Animals 1: Sponges, Radiata, Platyhelminthes, and Protostomes

Diversity of Animals 2: Deuterostomes: Vertebrates and Their Closest Relatives

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Conservation of Biodiversity

Putting Selection to Work

Organization of the Plant Body

Transport in Plants

Reproduction and Development in Flowering Plants

Plant Nutrition

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Transport in Animals: the Circulatory System

Reproduction in Animals

Animal Development

Control of Animal Processes: Neural Control

Control of Animal Processes: Neural Control

Control of Animal Processes: Neural Integration

Muscles, Skeletons, and Body Movements

Animal Behaviour

Animal Nutrition

Gas Exchange: the Respiratory System

Regulating the Internal Environment

Defences Against Disease

Conservation and Evolutionary Physiology

Filters