Chapter 3

Question 1

or cell membrane, forms the outer boundary of the cell, through which the cell interacts with its external environment.

Answer 1

plasma membrane

Question 2

is usually located centrally; it directs cell activities

Answer 2

nucleus

Question 3

located between the plasma membrane and the nucleus

Answer 3

cytoplasm

Question 4

involves all chemical reactions that occur within a cell. These metabolic reactions often involve energy transfers, meaning the energy released by one reaction is then used in another reaction.

Answer 4

Cell metabolism and energy use

Question 5

produce, various types of molecules, including proteins, nucleic acids, and lipids. The structural and functional characteristics of cells are determined by the types of molecules they produce.

Answer 5

Synthesis of molecules

Question 6

with each other by using chemical and electrical signals.

Answer 6

Communication

Question 7

Most cells contain a complete copy of all the genetic information of the individual. This genetic information ultimately determines the structural and functional characteristics of the cell.

Answer 7

Reproduction and inheritance

Question 8

allow us to visualize the general features of cells, such as the nucleus. But the magnification of light microscopes is limited, so not all cell structures can be thoroughly investigated.

Answer 8

Light microscopes

Question 9

can reveal features of the cell surface and the surfaces of internal structures.

Answer 9

scanning electron microscope (SEM)

Question 10

allows us to see “through” parts of the cell and thus to discover detailed aspects of cell structure. A more detailed description of microscopes and their use appears in Clinical Impact, “Microscopic Imaging,” in this chapter.

Answer 10

transmission electron microscope (TEM)

Question 11

is a result of the cell’s regulation of ion movement into and out of the cell. Because there are more positively charged ions immediately on the outside of the plasma membrane and more negatively charged ions and proteins inside, the outside of the plasma membrane is positively charged, compared with the inside of the plasma membrane.

Answer 11

membrane potential

Question 12

is the collection of glycolipids, glycoproteins, and carbohydrates on the outer surface of the plasma membrane.

Answer 12

glycocalyx

Question 13

are integral proteins that allow ions or molecules to move from one side of the plasma membrane to the other. Transport proteins have three characteristics that are important to their function: specificity, saturation, and competition.

Answer 13

Transport proteins

Question 14

means that each transport protein binds to and transports only a certain type of molecule or ion

Answer 14

Specificity

Question 15

is the result of molecules with simlilar shape binding to the transport protein

Answer 15

Competition

Question 16

means that the rate of movement of molecules across the membrane is limited by the number of available transport proteins

Answer 16

Saturation

Question 17

are one or more integral membrane proteins arranged so that they form a tiny channel through the plasma membrane

Answer 17

Channel proteins

Question 18

is a generic term for any chemical signal molecule used by cells to communicate with each other

Answer 18

Ligand

Question 19

is a genetic disorder that affects chloride ion channels. The failure of these ion channels to function causes the affected cells to produce thick, viscous secretions.

Answer 19

Cystic fibrosis

Question 20

or transporters, are integral membrane proteins that move ions or molecules from one side of the plasma membrane to the other.

Answer 20

Carrier proteins,

Question 21

are transport proteins that require cellular energy to move specific ions or molecules from one side of the plasma membrane to the other. The activity of ATP-powered pumps is fueled by the breakdown of adenosine triphosphate (ATP).

Answer 21

ATP-powered pumps

Question 22

acts as an intermediary between a receptor and other cellular proteins. The G protein complex consists of three proteins: alpha (α), beta (β), and gamma (γ) proteins.

Answer 22

G protein complex

Question 23

that is, it allows only certain substances to pass through it. The intracellular material has a different composition than the extracellular material, and the cell’s survival depends on the maintenance of these differences.

Answer 23

selectively permeable

Question 24

The liquid or gas

Answer 24

solvent

Question 25

the substances dissolved

Answer 25

solutes

Question 26

A concentration difference occurs when the solutes are not evenly distributed in a solvent. The concentration difference between two points, divided by the distance between the two points

Answer 26

concentration gradient

Question 27

is a measure of a fluid’s resistance to flow. A fluid with a low viscosity flows more easily, and a fluid with a high viscosity flows less easily.

Answer 27

Viscosity

Question 28

is the diffusion of water (solvent) across a selectively permeable membrane, such as a plasma membrane (

Answer 28

Osmosis

Question 29

or water channel proteins, that open and close to adjust membrane permeability to water. Water diffuses from a solution with proportionately more water, across a selectively permeable membrane, and into a solution with proportionately less water.

Answer 29

aquaporins

Question 30

is the force required to prevent water from moving by osmosis across a selectively permeable membrane. The osmotic pressure of a solution can be determined by placing the solution into a tube that is closed at one end by a selectively permeable membrane

Answer 30

Osmotic pressure

Question 31

If the cell swells enough, it can rupture

Answer 31

lysis

Question 32

the cellular material outside the nucleus but inside the plasma membrane, is about half cytosol and half organelles.

Answer 32

Cytoplasm

Question 33

is a colloid, a viscous solution containing dissolved ions and molecules as well as suspended molecules, especially proteins.

Answer 33

cytosol

Question 34

supports the cell and holds the nucleus and other organelles in place. In addition, some components of the cytoskeleton are responsible for changes in cell shape and the movement of cell organelles.

Answer 34

cytoskeleton

Question 35

is a large, membrane-bound structure usually located near the center of the cell. It may be spherical, elongated, or lobed, depending on the cell type. All body cells have a nucleus at some point in their life cycle

Answer 35

nucleus

Question 36

are hollow tubes composed primarily of protein units called tubulin. They are about 25 nanometers (nm) in diameter, with walls about 5 nm thick.

Answer 36

Microtubules

Question 37

which means “cell-eating,” solid particles are ingested and phagocytic vesicles are formed. White blood cells and some other cell types phagocytize bacteria, cell debris, and foreign particles

Answer 37

phagocytosis

Question 38

is composed of flattened, membranous sacs, containing cisternae, stacked on each other like dinner plates, it is thought to be a packaging and distribution center because it modifies, packages, and distributes proteins and lipids manufactured by the rough and smooth endoplasmic reticula

Answer 38

Golgi apparatus

Question 39

consists of three nucleotides and is complementary to a particular codon of mRNA. On the basis of the pairing relationships between nucleotides, the anticodon can combine only with its matched codon. For example, the tRNA that has the anticodon CUA combines with the codon GAU of mRNA. T

Answer 39

anticodon

Question 40

refers to abnormal tissue growth from rapid cell proliferation that continues after normal growth would have stopped.

Answer 40

neoplasm

Question 41

is the study of tumors and the problems they cause.

Answer 41

Oncology

Question 42

with malice or intent to cause harm, able to spread and become worse.

Answer 42

malignant

Question 43

Cancer cells can dislodge; enter blood vessels, lymphatic vessels, or body cavities; and travel to distant sites, where they invade tissues. The process by which cancer spreads to distant sites

Answer 43

metastasis

Question 44

is the division of the cell’s cytoplasm to produce two new cells, begins in anaphase and continues through telophase

Answer 44

Cytokinesis