Chapter 2 - The Cell: Overview

Question 1

light microscopy

Answer 1

Microscope that uses light to illuminate the specimen.

Question 2

electron microscopy

Answer 2

A microscope that uses electrons to illuminate the specimen.

Question 3

plasma membrane

Answer 3

The outer limit of the cytoplasm responsible for the regulation of substances moving into and out of cells.

Question 4

cytoplasm

Answer 4

All parts of the cell that surround the central nuclear or nucleoid region.

Question 5

organelles

Answer 5

The nucleus and other specialized internal structures and compartments of eukaryotic cells.

Question 6

cytoskeleton

Answer 6

The interconnected system of protein fibres and tubes that extends throughout the cytoplasm of a eukaryotic cell.

Question 7

prokaryotes

Answer 7

Organism in which the DNA is suspended in the cell interior without separation from other cellular components by a discrete membrane.

Question 8

nucleoid

Answer 8

The central region of a prokaryotic cell with no boundary membrane separating it from the cytoplasm, where DNA replication and RNA transcription occur.

Question 9

chromosome

Answer 9

The nuclear unit of genetic information, consisting of a DNA molecule and associated proteins

Question 10

ribosome

Answer 10

A ribonucleoprotein particle that carries out protein synthesis by translating mRNA into chains of amino acids.

Question 11

cell wall

Answer 11

A rigid external layer of material surrounding the plasma membrane of cells in plants, fungi, bacteria, and some protists, providing cell protection and support.

Question 12

flagella

Answer 12

A long, threadlike, cellular appendage responsible for movement; found in both prokaryotes and eukaryotes, but with different structures and modes of locomotion.

Question 13

cilia

Answer 13

Motile structure, extending from a cell surface, that moves a cell through fluid or fluid over a cell.

Question 14

pili

Answer 14

A hair or hairlike appendage on the surface of a prokaryote.

Question 15

nuclear envelope

Answer 15

In eukaryotes, membranes separating the nucleus from the cytoplasm.

Question 16

nuclear pores

Answer 16

Opening in the membrane of the nuclear envelope through which large molecules, such as RNA and proteins, move between the nucleus and the cytoplasm.

Question 17

chromatin

Answer 17

The structural building block of a chromosome, which includes the complex of DNA and its associated proteins.

Question 18

eukaryotes

Answer 18

Organism in which the DNA is enclosed in a nucleus.

Question 19

nucleoli

Answer 19

The nuclear site of rRNA transcription, processing, and ribosome assembly in eukaryotes.

Question 20

vesicles

Answer 20

A small, membrane-bound compartment that transfers substances between parts of the endomembrane system

Question 21

rough endoplasmic reticulum

Answer 21

Endoplasmic reticulum with many ribosomes studding its outer surface.

Question 22

smooth endoplasmic reticulum

Answer 22

Endoplasmic reticulum with no ribosomes attached to its membrane surfaces. Smooth ER has various functions, including synthesis of lipids that become part of cell membranes.

Question 23

Golgi complex

Answer 23

In eukaryotes, the organelle responsible for the final modification, sorting, and distribution of proteins and lipids.

Question 24

endocytosis

Answer 24

In eukaryotes, the process by which molecules are brought into the cell from the exterior involving a bulging in of the plasma membrane that pinches off to form an endocytic vesicle.

Question 25

exocytosis

Answer 25

In eukaryotes, the process by which a secretory vesicle fuses with the plasma membrane and releases the vesicle contents to the exterior.

Question 26

lysosomes

Answer 26

Membrane-bound vesicle containing hydrolytic enzymes for the digestion of many complex molecules

Question 27

phagocytosis

Answer 27

Process in which some types of cells engulf bacteria or other cellular debris to break them down.

Question 28

mitochondria

Answer 28

Membrane-bound organelle responsible for synthesis of most of the ATP in eukaryotic cells.

Question 29

cristae

Answer 29

Fold that expands the surface area of the inner mitochondrial membrane.

Question 30

mitochondrial matrix

Answer 30

The innermost compartment of the mitochondrion.

Question 31

microtubules

Answer 31

A cytoskeletal component formed by the polymerization of tubulin into rigid, hollow rods about 25 nm in diameter.

Question 32

centrosome

Answer 32

The main microtubule organizing centre of a cell, which organizes the microtubule cytoskeleton during interphase and positions many of the cytoplasmic organelles.

Question 33

centrioles

Answer 33

A cylindrical structure consisting of nine triplets of microtubules in the centrosomes of most animal cells

Question 34

intermediate filaments

Answer 34

A cytoskeletal filament about 10 nm in diameter that provides mechanical strength to cells in tissues.

Question 35

microfilaments

Answer 35

A cytoskeletal filament composed of actin.

Question 36

chloroplasts

Answer 36

The site of photosynthesis in plant cells.

Question 37

central vauole

Answer 37

A large, water-filled organelle in plant cells that maintains the turgor of the cell and controls movement of molecules between the cytosol and sap.

Question 38

function of smooth ER

Answer 38

synthesis of lipids that become part of cell membranes

Question 39

function of rough ER

Answer 39

The proteins made on ribosomes attached to the ER enter the ER lumen, where they fold into their final form.
The proteins are then delivered to other regions of the cell within small vesicles that pinch off from the ER, travel through the cytosol, and join with the organelle that performs the next steps in their modification and distribution. For most of the proteins made on the rough ER, the next destination is the Golgi complex, which packages and sorts them for delivery to their final destinations.