Ch. 3 Defined Words

Question 1

Plasma membrane

Answer 1

A cell membrane; also called a plasmalemma

Question 2

Cytoplasm

Answer 2

The material between the plasma membrane and the nuclear membrane; cell contents.

Question 3

Cytosol

Answer 3

The fluid portion of the cytoplasm; also called intracellular fluid.

Question 4

Organelle

Answer 4

An intracellular structure with a specific function or group of functions.

Question 5

Cytoskeleton

Answer 5

A network of microtubules and microfilaments in the cytoplasm.

Question 6

Microfilaments

Answer 6

Fine protein filaments visible with the electron microscope; components of cytoskeleton.

Question 7

Actin

Answer 7

the protein component of microfilaments in skeletal muscles and produces contractions of all uncles through interaction with thick (myosin) filaments

Question 8

Microtubules

Answer 8

Microscopic tubules that are part of the cytoskeleton and are a component in cilia, flagella, the centrioles, and spindle fibers.

Question 9

Microvilli

Answer 9

Small, finger like extensions of the exposed plasma membrane of an epithelial cell.

Question 10

Centrosome

Answer 10

a region of cytoplasm that contains a pair of centrioles oriented at right angles to one another.

Question 11

Centriole

Answer 11

A cylindrical intracellular organelle composed of nine groups of microtubules, three I n each group (9 + 0 array); functions in mitosis or meiosis by organizing the microtubules of the spindle apparatus.

Question 12

Flagellum/Flagella

Answer 12

An organelle that is structurally similar to a motile ilium but is used to propel a cell through a fluid; found on sperm.

Question 13

Ribosome

Answer 13

An organelle that contains rRNA and proteins and essential to mRNA translation and protein synthesis.

Question 14

Endoplasmic reticulum

Answer 14

A network of membranous channels in the cytoplasm of a cell that function in intracellular transport, synthesis, storage, packaging, and secretion.

Question 15

Cisterna

Answer 15

An expanded or flattened chamber derived from and associated with the endoplasmic reticulum.

Question 16

Smooth endoplasmic reticulum (SER)

Answer 16

A membranous organelle in which lipid and carbohydrate synthesis and storage occur.

Question 17

Rough endoplasmic reticulum (RER)

Answer 17

A membranous organelle that is a site of protein synthesis and storage.

Question 18

Golgi apparatus

Answer 18

A cellular organelle consisting of a series of membranous plates that give rise to lysosomes and secretory vesicles.

Question 19

Lysosome

Answer 19

An intracellular vesicle containing digestive enzymes.

Question 20

Autolysis

Answer 20

The destruction of cell due to the rupture of lysosomal membranes in its cytoplasm

Question 21

Peroxisome

Answer 21

A membranous vesicle containing enzymes that break down hydrogen peroxide (H2O2)

Question 22

Mitochondrion

Answer 22

An intracellular organelle responsible for generating most of the ATP required for cellular operations.

Question 23

Crista/cristae

Answer 23

A ridge-shaped collection of hair cells in the ampulla of a semicircular duct; the crista and cupola form a receptor complex sensitive to movement along the plane of the semicircular canal.

Question 24

Matrix

Answer 24

The extra cellular fibers and ground substance of a connective tissue.

Question 25

Glycolysis

Answer 25

The anaerobic cytosolic breakdown of couches into two 3-carbon molecules of pyruvate, with a net gain of 2 ATP molecules.

Question 26

Citric acid cycle

Answer 26

The reaction sequence that occurs in the matrix of mitochondria; in the process, organic molecules are broken down, carbon dioxide molecules are released, and hydrogen molecules are transferred by coenzymes to the electron transport chain

Question 27

Aerobic metabolism

Answer 27

The complete breakdown of organic substrates into carbon dioxide and water; a process tat yields large amounts of ATP but require mitochondria and oxygen.

Question 28

Membrane flow

Answer 28

The continuous movement and exchange of membrane segments.