Chapter 2- The Cell and Its Components

Question 1

What is a nucleolus?

Answer 1

A non-membrane-bound structure in the nucleus, which contains RNA and protein.

Question 2

What is a nuclear envelope?

Answer 2

A double membrane surrounding the nucleus.

Question 3

What is the nuclear pore complex?

Answer 3

A group of proteins forming openings in the nuclear envelope.

Question 4

What is the endoplasmic reticulum? (ER)

Answer 4

A complex system of channels and sacs composed of membranes enclosing a lumen; made up of two parts, the rough ER and the smooth ER.

Question 5

What is a ribosome?

Answer 5

A structure composed of RNA and proteins, and responsible for the synthesis of polypeptides in the cytosol and on the surface of the rough endoplasmic reticulum.

Question 6

What is the endomembrane system?

Answer 6

The system within a cell that acts to synthesize, modify and transport proteins and other cell products; includes the endoplasmic reticulum, the Golgi apparatus, vesicles and the cell membrane, among other structures.

Question 7

What is a vesicle?

Answer 7

A membrane-enclosed sac used for transport and storage.

Question 8

What is the Golgi apparatus?

Answer 8

A stack of curved membrane sacs that packages, processes, sorts and distributes proteins, lipids, and other substances within the cell; acts like a “post office” for the cell.

Question 9

What is a lysosome?

Answer 9

A membrane-bound vesicle containing enzymes that catalyze hydrolysis reactions, breaking down macromolecules.

Question 10

What is a peroxisome?

Answer 10

A membrane-bound sac containing oxidative enzymes that break down excess fatty acids and hydrogen peroxide, and particpate in the synthesis of bile acids and cholesterol.

Question 11

What is a vacuole?

Answer 11

A large, membrane-bound sac in plant cells and some other cells that store water, ions, macromolecules, sugars, and amino acids.

Question 12

What is a chloroplast?

Answer 12

An organelle in the cells of photosynthetic organisms in which light energy from the sun is captured and stored in the form of high-energy organic molecules such as glucose.

Question 13

What is the mitochondrion?

Answer 13

An organelle in eukaryotic cells in which high-energy organic molecules are oxidized to obtain energy.

Question 14

What is the cell wall?

Answer 14

A rigid layer surrounding the plant, algae, fungal, bacterial, and some archaea cells, composed of proteins and/or carbohydrates; gives the cell its shape and structural support.

Question 15

What is the cytoskeleton?

Answer 15

A network of protein fibres that extends throughout the cytosol, providing structure, shape, support and motility.

Question 16

What is the fluid mosaic model?

Answer 16

The accepted model of the cell membrane which is a basic framework of a semi-fluid phospholipid bilayer with a mosaic of proteins; carbohydrates may be attached to lipids or proteins.

Question 17

What is passive transport?

Answer 17

The movement of ions or molecules across a cell membrane from a region of higher concentration to a region of lower concentration, without the input of energy.

Question 18

What is the concentration gradient?

Answer 18

A difference in concentration between one side of a membrane and the other.

Question 19

What is diffusion?

Answer 19

The net movement of ions of molecules from an area of higher concentration to an area of lower concentraion..

Question 20

What is osmosis?

Answer 20

The movement of water from an area of high concentration to an area of lower concentration, across a semi-permeable membrane.

Question 21

What is facilitated diffusion?

Answer 21

The transport of ions or molecules across a membrane by means of a membrane protein along the concentration gradient for that ion or molecule.

Question 22

What is a channel protein?

Answer 22

A membrane protein that forms a channel across a cell membrane, which allows specific ions or molecules to cross the membrane along their concentration gradients.

Question 23

What is a carrier protein?

Answer 23

A membrane protein that binds to and transports one or more particles of a substance from one side of a membrane to the other, along with the concentration gradient for that substance.

Question 24

What is active transport?

Answer 24

The transport of a solute across a membrane against its concentration gradient.

Question 25

What is membrane-assisted transport?

Answer 25

Transport method used to move materials that are too large to cross the cell membrane through a channel or carrier protein.

Question 26

What is endocytosis?

Answer 26

The process by which the cell membrane engulfs extracellular material to bring it in inside the cell.

Question 27

What is phagocytosis?

Answer 27

Endocytosis involving solid particles (cell-eating)

Question 28

What is pinocytosis?

Answer 28

Endocytosis involving liquid particles (cell-drinking)

Question 29

What is exocytosis?

Answer 29

Opposite of endocytosis, transport method in which a vesicle fuses with the cell membrane and releases its contents outside the cell.