ch. 4 the end-membrane system

Question 1

the interior of a eukaryotic cell is packed with membranes that form an elaborate internal, or _________, system.

Answer 1

endomembrane

Question 2

what does this endomembrane system do?

Answer 2

-fills the cell, dividing in into compartments , channeling the passage of molecules through the interior of the cell, and providing surfaces for the synthesis of lipids and some proteins.

Question 3

the ________ __________(ER) is the largest internal membrane. The ER is composed of a phospholipid bilayer embedded with proteins.

Answer 3

endoplasmic reticulum

Question 4

Ribosomes associated with the cytoplasmic face of the______ extrude newly made proteins into the interior or lumen. The ______ is a more tubelike structure connected to the _____.

Answer 4

RER, SER, RER

Question 5

purposes of the SER

Answer 5

-membranes of the SER contain many embedded enzymes, involved in the synthesis of a variety of carbohydrates and lipids.
-Steroid hormones are also synthesized in the SER.

Question 6

Cells that carry out extensive lipid syntheses, such as those in the testes, intestine, and brain, have abundant _ _ _. Cells that synthesize secreted proteins, like antibodies, have more extensive _ _ _.

Answer 6

SER, RER

Question 7

flattened stacks of membranes form a complex called the ______ or ________.

Answer 7

golgi body, golgi apparatus

Question 8

individual stacks of membrane are called ________ and they vary in number within the Golgi body from 1 or a few in protists to 20 or more animals cells, and to several hundred in plant cells.

Answer 8

cistern

Question 9

function of golgi body

Answer 9

functions in the collection, packaging, and distribution of molecules synthesized at one location and used at another within the cell or outside of it.

Question 10

_______ are digestive vesicles that arise from the Golgi apparatus, They contain high levels of a variety of enzymes that can degrade proteins, nucleic acids, lipids, and carbohydrates.

Answer 10

lysosomes

Question 11

______ droplets are organelles with a different structure from the rest of the endomembrane system. They consist of a neutral lipid core surrounded by a single layer of phospholipid.

Answer 11

lipid

Question 12

eukaryotic cells have a variety of vesicles called that contain enzymes.

Answer 12

microbodies

Question 13

peroxisomes

Answer 13

microbodies than contain enzymes used to oxidize fatty acids.

Question 14

plant cells have specialized membrane-bounded structures called _______.

Answer 14

vacuoles