Chapter 3.3

Question 1

cell wall

Answer 1

a rigid cell covering made of cellulose in plants, peptidoglycan in bacteria, non-peptidoglycan compounds in Archaea, and chitin in fungi that protects the cell, provides structural support, and gives shape to the cell

Question 2

central vacuole

Answer 2

a large plant cell organelle that acts as a storage compartment, water reservoir, and site of macromolecule degradation

Question 3

chloroplast

Answer 3

a plant cell organelle that carries out photosynthesis

Question 4

cilium

Answer 4

(plural: cilia) a short, hair-like structure that extends from the plasma membrane in large numbers and is used to move an entire cell or move substances along the outer surface of the cell

Question 5

cytoplasm

Answer 5

the entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals

Question 6

cytoskeleton

Answer 6

the network of protein fibers that collectively maintains the shape of the cell, secures some organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move

Question 7

cytosol

Answer 7

the gel-like material of the cytoplasm in which cell structures are suspended

Question 8

desmosome

Answer 8

a linkage between adjacent epithelial cells that forms when cadherins in the plasma membrane attach to intermediate filaments

Question 9

endomembrane system

Answer 9

the group of organelles and membranes in eukaryotic cells that work together to modify, package, and transport lipids and proteins

Question 10

endoplasmic reticulum (ER)

Answer 10

a series of interconnected membranous structures within eukaryotic cells that collectively modify proteins and synthesize lipids

Question 11

extracellular matrix

Answer 11

the material, primarily collagen, glycoproteins, and proteoglycans, secreted from animal cells that holds cells together as a tissue, allows cells to communicate with each other, and provides mechanical protection and anchoring for cells in the tissue

Question 12

flagellum

Answer 12

(plural: flagella) the long, hair-like structure that extends from the plasma membrane and is used to move the cell

Question 13

gap junction

Answer 13

a channel between two adjacent animal cells that allows ions, nutrients, and other low-molecular weight substances to pass between the cells, enabling the cells to communicate

Question 14

Golgi apparatus

Answer 14

an eukaryotic organelle made up of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution

Question 15

lysosome

Answer 15

an organelle in an animal cell that functions as the cell’s digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles

Question 16

mitochondria

Answer 16

(singular: mitochondrion) the cellular organelles responsible for carrying out cellular respiration, resulting in the production of ATP, the cell’s main energy-carrying molecule

Question 17

nuclear envelope

Answer 17

the double-membrane structure that constitutes the outermost portion of the nucleus

Question 18

nucleolus

Answer 18

the darkly staining body within the nucleus that is responsible for assembling ribosomal subunits

Question 19

nucleus

Answer 19

the cell organelle that houses the cell’s DNA and directs the synthesis of ribosomes and proteins

Question 20

peroxisome

Answer 20

a small, round organelle that contains hydrogen peroxide, oxidizes fatty acids and amino acids, and detoxifies many poisons

Question 21

plasma membrane

Answer 21

a phospholipid bilayer with embedded (integral) or attached (peripheral) proteins that separates the internal contents of the cell from its surrounding environment

Question 22

plasmodesma

Answer 22

(plural: plasmodesmata) a channel that passes between the cell walls of adjacent plant cells, connects their cytoplasm, and allows materials to be transported from cell to cell

Question 23

ribosome

Answer 23

a cellular structure that carries out protein synthesis

Question 24

rough endoplasmic reticulum (RER)

Answer 24

the region of the endoplasmic reticulum that is studded with ribosomes and engages in protein modification

Question 25

smooth endoplasmic reticulum (SER)

Answer 25

the region of the endoplasmic reticulum that has few or no ribosomes on its cytoplasmic surface and synthesizes carbohydrates, lipids, and steroid hormones; detoxifies chemicals like pesticides, preservatives, medications, and environmental pollutants, and stores calcium ions

Question 26

tight junction

Answer 26

a firm seal between two adjacent animal cells created by protein adherence

Question 27

vacuole

Answer 27

a membrane-bound sac, somewhat larger than a vesicle, that functions in cellular storage and transport

Question 28

vesicle

Answer 28

a small, membrane-bound sac that functions in cellular storage and transport; its membrane is capable of fusing with the plasma membrane and the membranes of the endoplasmic reticulum and Golgi apparatus