Kapitel 15

Question 1

Mechanism by which a cell “eats itself -” digesting molecules and organelles that are damaged or obsolete.

Answer 1

autophagy

Question 2

Protein that makes up the coat of a type of transport vesicle that buds from either the Golgi apparatus (on the outward secretory pathway) or from the plasma membrane (on the inward endocytic pathway).

Answer 2

clathrin

Question 3

Small membrane-enclosed sac that wears a distinctive layer of proteins on its cytosolic surface. It is formed by pinching-off of a protein-coated region of cell membrane.

Answer 3

coated vesicle

Question 4

Process by which cells take in materials through an invagination of the plasma membrane - which surrounds the ingested material in a membrane-enclosed vesicle. (See alsopinocytosis and phagocytosis.)

Answer 4

endocytosis

Question 5

Interconnected network of membrane-enclosed organelles in a eukaryotic cell; includes the endoplasmic reticulum - Golgi apparatus - lysosomes - peroxisomes - and endosomes.

Answer 5

endomembrane system

Question 6

Labyrinthine membrane-enclosed compartment in the cytoplasm of eukaryotic cells where lipids and proteins are made.

Answer 6

endoplasmic reticulum (ER)

Question 7

Membrane-enclosed compartment of a eukaryotic cell through which material ingested by endocytosis passes on its way to lysosomes.

Answer 7

endosome

Question 8

Process by which most molecules are secreted from a eukaryotic cell. These molecules are packaged in membrane-enclosed vesicles that fuse with the plasma membrane - releasing their contents to the outside.

Answer 8

exocytosis

Question 9

Membrane-enclosed organelle in eukaryotic cells that modifies the proteins and lipids made in the endoplasmic reticulum and sorts them for transport to other sites.

Answer 9

Golgi apparatus

Question 10

Membrane-enclosed organelle that breaks down worn-out proteins and organelles and other waste materials - as well as molecules taken up by endocytosis; contains digestive enzymes that are typically most active at the acid pH found inside these organelles.

Answer 10

lysosome

Question 11

Double membrane surrounding the nucleus. Consists of outer and inner membranes - perforated by nuclear pores.

Answer 11

nuclear envelope

Question 12

Channel through which selected large molecules move between the nucleus and the cytoplasm.

Answer 12

nuclear pore

Question 13

Small membrane-enclosed organelle that contains enzymes that degrade lipids and destroy toxins.

Answer 13

peroxisome

Question 14

A cell such as a macrophage or neutrophil that is specialized to take up particles and microorganisms by phagocytosis.

Answer 14

phagocytic cell

Question 15

The process by which particulate material is engulfed (“eaten”) by a cell. Prominent in predatory cells - such as Amoeba proteus - and in cells of the vertebrate immune system such as macrophages.

Answer 15

phagocytosis

Question 16

Type of endocytosis in which soluble materials are taken up from the environment and incorporated into vesicles for digestion. (Literally - “cell drinking.”)

Answer 16

pinocytosis

Question 17

A family of small GTP-binding proteins present on the surfaces of transport vesicles and organelles that serves as a molecular marker to help ensure that transport vesicles fuse only with the correct membrane.

Answer 17

Rab protein

Question 18

Mechanism of selective uptake of material by animal cells in which a macromolecule binds to a receptor in the plasma membrane and enters the cell in a clathrin-coated vesicle.

Answer 18

receptor-mediated endocytosis

Question 19

Region of the endoplasmic reticulum associated with ribosomes and involved in the synthesis of secreted and membrane-bound proteins.

Answer 19

rough endoplasmic reticulum

Question 20

Production and release of a substance from a cell.

Answer 20

secretion

Question 21

Membrane-enclosed organelle in which molecules destined for secretion are stored prior to release. Sometimes called a secretory granule because darkly staining contents make the organelle visible as a small solid object.

Answer 21

secretory vesicle

Question 22

Amino acid sequence that directs a protein to a specific location in the cell - such as the nucleus or mitochondria.

Answer 22

signal sequence

Question 23

One of a family of membrane proteins responsible for the selective fusion of vesicles with a target membrane inside the cell.

Answer 23

SNARE

Question 24

Membrane vesicle that carries proteins from one intracellular compartment to another - for example - from the endoplasmic reticulum to the Golgi apparatus.

Answer 24

transport vesicle

Question 25

Molecular program triggered by the accumulation of misfolded proteins in the endoplasmic reticulum. Allows cells to expand the endoplasmic reticulum and produce more of the molecular machinery needed to restore proper protein folding and processing.

Answer 25

unfolded protein response (UPR)

Question 26

Movement of material between organelles in the eukaryotic cell via membrane-enclosed vesicles.

Answer 26

vesicular transport

Question 27

Section of the Golgi apparatus that receives materials from the endoplasmic reticulum.

Answer 27

cis Golgi network

Question 28

White blood cell that mediates the immune response to foreign molecules (antigens). Can be an antibody-secreting B cell type or the T cell type that recognizes and ultimately eliminates infected cells.

Answer 28

lymphocyte

Question 29

Cell found in animal tissues that defends against infections by ingesting invading microbes by a process of phagocytosis; derived from a type of white blood cell.

Answer 29

macrophage

Question 30

Describes an ability to catalyze consecutive reactions or undergo multiple conformational changes without releasing a substrate. Examples include replication by DNA polymerase or the movement of motor proteins involved in transport - such as kinesin.

Answer 30

processive

Question 31

Region of the endoplasmic reticulum not associated with ribosomes; involved in the synthesis of lipids.

Answer 31

smooth endoplasmic reticulum (SER)

Question 32

Intimate association between two organisms of different species from which both derive a long-term selective advantage.

Answer 32

symbiosis

Question 33

Portion of the Golgi apparatus furthest from the endoplasmic reticulum and from which proteins and lipids leave for lysosomes - secretory vesicles - or the cell surface.

Answer 33

trans Golgi network (TGN)

Question 34

Small - membrane-enclosed - spherical sac in the cytoplasm of a eukaryotic cell.

Answer 34

vesicle