Question 1

The ________ functions in cell lubrication,adhesion,and signaling.

Accepted Answer

The answer of The ________ functions in cell lubrication,adhesion,and signaling....

Question 2

Integral proteins always extend completely through the plasma membrane.

Accepted Answer

A) True 
 B)False

Question 3

Diffusion is a process by which a substance:

Accepted Answer

A) goes from lesser to greater concentration. 
B) goes down its concentration gradient. 
C) goes up its concentration gradient. 
D) is at equilibrium. 
A) goes from lesser to greater concentration. 
B) goes down its concentration gradient. 
C) goes up its concentration gradient. 
D) is at equilibrium.

Question 4

Red blood cells placed in pure water will swell and burst.What process is causing this to happen?

Accepted Answer

A) Water is diffusing across the plasma membrane from a region of high (outside the cell)to low (inside the cell)"free" water concentration. 
B) Water is being pulled into the cell by the cell's solutes. 
C) Water is diffusing across the plasma membrane from a region of low (outside the cell)to high (inside the cell)"free" water concentration. 
D) Solutes are being drawn into the cell across the plasma membrane. 
E) Ions are diffusing across the plasma membrane and destabilizing the phospholipids. 
A) Water is diffusing across the plasma membrane from a region of high (outside the cell)to low (inside the cell)"free" water concentration. 
B) Water is being pulled into the cell by the cell's solutes. 
C) Water is diffusing across the plasma membrane from a region of low (outside the cell)to high (inside the cell)"free" water concentration. 
D) Solutes are being drawn into the cell across the plasma membrane. 
E) Ions are diffusing across the plasma membrane and destabilizing the phospholipids.

Question 5

A main function of the carbohydrates that form the glycocalyx is to:

Accepted Answer

A) move large molecules in and out of the cell. 
B) regulate water movement into the cell. 
C) bind cell membranes to the cytoskeleton. 
D) act as binding sites for signaling molecules. 
E) maintain the proper fluidity of the plasma membrane. 
A) move large molecules in and out of the cell. 
B) regulate water movement into the cell. 
C) bind cell membranes to the cytoskeleton. 
D) act as binding sites for signaling molecules. 
E) maintain the proper fluidity of the plasma membrane.

Question 6

Signals sent between cells reach a cell at receptor proteins.

Accepted Answer

A) True 
 B)False

Question 7

Calcium ions (Ca²⁺)are present in the endoplasmic reticulum at concentrations 1,000 times higher than in the cytosol (the gel-like part of the cell outside organelles).One protein on the endoplasmic reticulum membrane is devoted to allowing Ca²⁺ to move from the endoplasmic reticulum to the cytosol,and another protein moves Ca²⁺ from the cytosol to the endoplasmic reticulum.These processes are not trivial-Ca²⁺ released into the cytosol allows,for example,for muscle contraction and communication between nerve cells.In this pair of Ca²⁺ transport proteins,you would predict that the protein moving Ca²⁺ from the endoplasmic reticulum to the cytosol ________,and the protein that moves Ca²⁺ from cytosol to the endoplasmic reticulum ________.

Accepted Answer

A) transports calcium slowly; transports calcium rapidly 
B) works without ATP; requires ATP 
C) requires ATP; works without ATP 
D) is large; is small 
E) is small; is large 
A) transports calcium slowly; transports calcium rapidly 
B) works without ATP; requires ATP 
C) requires ATP; works without ATP 
D) is large; is small 
E) is small; is large

Question 8

Membrane proteins perform all of the following functions except:

Accepted Answer

A) structural support. 
B) cell recognition. 
C) communication. 
D) transport. 
E) maintainance of membrane fluidity. 
A) structural support. 
B) cell recognition. 
C) communication. 
D) transport. 
E) maintainance of membrane fluidity.

Question 9

If you transferred a phospholipid bilayer from water to oil,what effect would this have on the membrane?

Accepted Answer

A) The membrane would become very rigid. 
B) The membrane would form four layers instead of its normal two. 
C) The membrane would be unaffected by the oil. 
D) The membrane would invert its normal structure by positioning the heads on the inside of the bilayer and the fatty-acid tails outside. 
E) The phospholipid bilayer would split into two separate layers, which each would be maintained in the oil. 
A) The membrane would become very rigid. 
B) The membrane would form four layers instead of its normal two. 
C) The membrane would be unaffected by the oil. 
D) The membrane would invert its normal structure by positioning the heads on the inside of the bilayer and the fatty-acid tails outside. 
E) The phospholipid bilayer would split into two separate layers, which each would be maintained in the oil.

Question 10

The 1985 Nobel Prize in Physiology or Medicine was awarded to Michael Brown and Joseph Goldstein for their work on cholesterol metabolism.Brown and Goldstein investigated the cause of remarkably high levels of circulating cholesterol found in certain families.Just as remarkable was the high incidence of heart disease in these families.What Brown and Goldstein found was not what might be expected-these individuals did not make too much cholesterol.Instead,most of these people had defects in receptor-mediated endocytosis (RME).What could possibly link high cholesterol levels in the blood and defective RME in these patients?

Accepted Answer

A) Cholesterol was being secreted from cells by RME at too high a rate and therefore accumulated in the blood. 
B) Cholesterol was not transported into cells by RME and therefore accumulated in the blood. 
C) Cholesterol was being secreted by facilitated diffusion at too high a rate and therefore accumulated in the blood. 
D) Cholesterol was not transported into cells by active transport proteins and therefore accumulated in the blood. 
E) Cholesterol was not transported into cells by facilitated diffusion and therefore accumulated in the blood. 
A) Cholesterol was being secreted from cells by RME at too high a rate and therefore accumulated in the blood. 
B) Cholesterol was not transported into cells by RME and therefore accumulated in the blood. 
C) Cholesterol was being secreted by facilitated diffusion at too high a rate and therefore accumulated in the blood. 
D) Cholesterol was not transported into cells by active transport proteins and therefore accumulated in the blood. 
E) Cholesterol was not transported into cells by facilitated diffusion and therefore accumulated in the blood.

Question 11

Cholesterol helps to maintain the correct fluidity of the plasma membrane.

Accepted Answer

A) True 
 B)False

Question 12

Osmosis is an example of passive transport.

Accepted Answer

A) True 
 B)False

Question 13

Active transport:

Accepted Answer

A) moves only large molecules into the cell. 
B) causes the production of ATP within the cell. 
C) increases the concentration of solute inside the cell. 
D) moves substances against their concentration gradient. 
A) moves only large molecules into the cell. 
B) causes the production of ATP within the cell. 
C) increases the concentration of solute inside the cell. 
D) moves substances against their concentration gradient.

Question 14

A substance moving down the concentration gradient is an example of active transport.

Accepted Answer

A) True 
 B)False

Question 15

The plasma membrane is composed of phospholipids,which are free to move laterally,and is peppered with both stationary and mobile proteins.This view of the plasma membrane is known as the:

Accepted Answer

A) peppered membrane model. 
B) phospholipid bilayer model. 
C) fluid-mosaic model. 
D) semipermeable membrane model. 
A) peppered membrane model. 
B) phospholipid bilayer model. 
C) fluid-mosaic model. 
D) semipermeable membrane model.

Question 16

The outer living limit of the cell is called the:

Accepted Answer

A) cell wall. 
B) edge. 
C) plastid. 
D) plasma membrane. 
A) cell wall. 
B) edge. 
C) plastid. 
D) plasma membrane.

Question 17

The central vacuoles of some plant cells you are studying fill with water and press the cell contents against their cell walls because of osmosis.What can you predict about the concentration of solutes in the solution that bathes the turgid plant cells?

Accepted Answer

A) The concentration of solutes outside the cell must be significantly lower than the concentration within the cell. 
B) The concentration of solutes outside the cell must be significantly higher than the concentration within the cell. 
C) There must be no solutes either outside or inside the cell. 
D) The concentration of solutes outside the cell must be about the same as that of seawater. 
E) The concentration of solutes outside the cell can't be predicted, because it's the concentration inside the cell that's important. 
A) The concentration of solutes outside the cell must be significantly lower than the concentration within the cell. 
B) The concentration of solutes outside the cell must be significantly higher than the concentration within the cell. 
C) There must be no solutes either outside or inside the cell. 
D) The concentration of solutes outside the cell must be about the same as that of seawater. 
E) The concentration of solutes outside the cell can't be predicted, because it's the concentration inside the cell that's important.

Question 18

Cholesterol is a hormone receptor in the plasma membrane.

Accepted Answer

A) True 
 B)False

Question 19

The plasma membrane is a semipermeable membrane.This means that it is:

Accepted Answer

A) permeable to small molecules except water. 
B) permeable to small and uncharged molecules but not to larger or charged substances. 
C) only permeable to cholesterol. 
D) permeable to large charged molecules but not to small uncharged molecules. 
A) permeable to small molecules except water. 
B) permeable to small and uncharged molecules but not to larger or charged substances. 
C) only permeable to cholesterol. 
D) permeable to large charged molecules but not to small uncharged molecules.

Question 20

The ________ of a phospholipid molecule will seek water,whereas the ________ of the molecules will avoid water.

Accepted Answer

A) tail; head 
B) head; tail 
C) hydrophobic portion; hydrophilic portion 
D) fatty acid; phosphate group 
A) tail; head 
B) head; tail 
C) hydrophobic portion; hydrophilic portion 
D) fatty acid; phosphate group

Exam 5: Lifes Border: the Plasma Membrane

The ________ functions in cell lubrication,adhesion,and signaling.

Integral proteins always extend completely through the plasma membrane.

Diffusion is a process by which a substance:

Red blood cells placed in pure water will swell and burst.What process is causing this to happen?

A main function of the carbohydrates that form the glycocalyx is to:

Signals sent between cells reach a cell at receptor proteins.

Membrane proteins perform all of the following functions except:

If you transferred a phospholipid bilayer from water to oil,what effect would this have on the membrane?

Cholesterol helps to maintain the correct fluidity of the plasma membrane.

Osmosis is an example of passive transport.

Active transport:

A substance moving down the concentration gradient is an example of active transport.

The plasma membrane is composed of phospholipids,which are free to move laterally,and is peppered with both stationary and mobile proteins.This view of the plasma membrane is known as the:

The outer living limit of the cell is called the:

The central vacuoles of some plant cells you are studying fill with water and press the cell contents against their cell walls because of osmosis.What can you predict about the concentration of solutes in the solution that bathes the turgid plant cells?

Cholesterol is a hormone receptor in the plasma membrane.

The plasma membrane is a semipermeable membrane.This means that it is:

The ________ of a phospholipid molecule will seek water,whereas the ________ of the molecules will avoid water.

Science As a Way of Learning: a Guide to the Natural World

Fundamental Building Blocks: Chemistry, water, and Ph

Lifes Components: Biological Molecules

Lifes Home: the Cell

Lifes Mainspring: an Introduction to Energy

Vital Harvest: Deriving Energy From Food

The Green Worlds Gift: Photosynthesis

The Links in Lifes Chain: Genetics and Cell Division

Preparing for Sexual Reproduction: Meiosis

The First Geneticist: Mendel and His Discoveries

Units of Heredity: Chromosomes and Inheritance

Passing on Lifes Information: Dna Structure and Replication

How Proteins Are Made: Genetic Transcription, translation, and Regulation

The Future Isnt What It Used to Be: Biotechnology

An Introduction to Evolution: Charles Darwin, evolutionary Thought, and the Evidence for Evolution

The Means of Evolution: Microevolution

The Outcomes of Evolution: Macroevolution

A Slow Unfolding: the History of Life on Earth

Arriving Late,traveling Far: the Evolution of Human Beings

Viruses,bacteria,archaea,and Protists: the Diversity of Life 1

Fungi: the Diversity of Life 2

Animals: the Diversity of Life 3

Plants: the Diversity of Life 4

The Angiosperms: Form and Function in Flowering Plants

Body Support and Movement: the Integumentary, skeletal, and Muscular Systems

Communication and Control 1: the Nervous System

Communication and Control 2: the Endocrine System

Defending the Body: the Immune System

Transport and Exchange 1: Blood and Breath

Transport and Exchange 2: Digestion, nutrition, and Elimination

An Amazingly Detailed Script: Animal Development

How the Baby Came to Be: Human Reproduction

An Interactive Living World 1: Populations in Ecology

An Interactive Living World 2: Communities in Ecology

An Interactive Living World 3: Ecosystems and Biomes

Filters

The of a phospholipid molecule will seek water,whereas the of the molecules will avoid water.