Exam 3 Terms

Question 1

Endomembrane System

Question 2

Lysosome

Question 3

Endosome

Question 4

Peroxisome

Question 5

Signal Sequence

Question 6

Nuclear Envelope

Answer 6

encloses the DNA and is formed from 2 concentric membrane where the inner membrane interacts directly with DNA and the outer membrane is more like the ER with which it is continuous with

Question 7

NLS

Answer 7

cytosolic protein

Question 8

Nuclear import receptor

Question 9

Protein Translocator

Question 10

Chaperone

Answer 10

chaperone proteins recognize misfolded proteins that are trying to leave the ER, and hold them from transport, aggregating(forming a incorrect structure), and attempt to help re-fold the protein properly

Question 11

ER Signal Sequence

Answer 11

Present in any protein that starts in the ER, and consists of 8 or more hydrophobic amino acids

Question 12

SRP

Answer 12

Signal Recognition Particle recognizes the ER signal AS SOON AS it has been translated

Question 13

SRP receptor

Answer 13

present in the ER membrane and receives ER signal from SRP, then SRP is released

Question 14

stop-transfer sequence

Answer 14

hydrophobic stretch of amino acids that when detected by a translocator protein, will be held on to by the translocator protein within the channel of a transmembrane protein
-after protein is fully translated, the stop-transfer sequence will also be released into the ER membrane

Question 15

start-transfer sequence

Answer 15

hydrophobic stretch of additional amino acids that

Question 16

Transport vesicles

Answer 16

small membrane sacs thats function is to transfer materials from one cellular compartment to another

Question 17

Secretory pathway

Answer 17

vesicle transport that takes proteins from the ER, through the Golgi, then to a final location that is either the lysosome or cell surface

Question 18

Endocytic pathway

Answer 18

3 different methods of endocytosis–phago, pino, receptor-mediated endo– that occur depending of the type and size of the molecule being ingested, and the type of cells involved and funtions to take materials from outside the cell and brings them into the cell for digestion, degradation, or incorporated into an endosome

Question 19

Coated vesicles

Answer 19

as vesicles pinch off of membranes, they usually have a protein coat on their CYTOSOLIC side that will eventually be shedded after the vesicle is fully formed

Question 20

Clathrin

Answer 20

the best studied coat protein that is found in both the secretory and endocytic pathways

Question 21

Adaptin

Answer 21

proteins located on the CYTOSOLIC side that receptors bind to, and are responsible for choosing the many different kinds of molecules that will be transported

Question 22

Dynamin

Answer 22

dynamin GTPase forms a ring around the neck of the vesicle and hydrolyzes GTP to help with pinching off of the vesicle

Question 23

Rab

Answer 23

Rab GTPase proteins sit on the cytosolic side of each vesicle and are recognized by tethering proteins, in which rab works together with, in order to mediate vesicle docking

Question 24

Tethering protein

Answer 24

proteins that sit on the CYTOSOLIC surface of the target membrane, and works together with Rab to mediate vesicle docking

Question 25

v-snare

Answer 25

an additional protein located ON the VESICLE, and helps provide further support and specificity in vesicle docking

Question 26

t-snare

Answer 26

an additional protein that is located on the TARGET MEMBRANE, and helps provide further support and specificity for vesicle docking

Question 27

glycosylation

Answer 27

occurs in the ER, and is a covalent modification to a protein that results in a covalent attachment of a 14-sugar chain to a protein

Question 28

dolichol

Answer 28

a special lipid that sugar is initially attached to in the process of glycosylation

Question 29

ER retention signal and example

Answer 29

An additional ER signal that ER-destined proteins contain -KDEL sequence that is recognized by receptors in both ER and Golgi

Question 30

Anterograde

Answer 30

traveling from ER --> Golgi

Question 31

Retrograde

Answer 31

traveling from Golgi-->ER

Question 32

UPR

Answer 32

Unfolded Protein Response--> can be triggered if too many misfolded proteins accumulate in the ER and it fixes issue by promoting formation of more ER chaperones and additional quality control proteins, or can trigger programmed cell death under extreme circumstances

Question 33

Cisternae

Answer 33

flattened membrane-bound sacs that are in the Golgi aparatus

Question 34

Constitutive exocytosis and 2 characteristics

Answer 34

a constant stream of transport vesicles off the TRANS golgi that delivers newly made lipids and proteins to the plasma membrane 1. delivers soluble proteins that will be released from the cell 2. DOES NOT require a signal sequence

Question 35

Regulated exocytosis and 2 characteristics

Answer 35

secretory vesicles that only operate in cells that are specialized for secretion 1. cells that make large quantities of specific molecules like hormones 2. molecules are held in secretory vesicles until their release is desired

Question 36

Secretory vesicles

Answer 36

vesicles that only operate in cells that are specialized for secretion

Question 37

Phagocytosis + example

Answer 37

"cellular eating"--ingestion of larger particles, including while cells or large pieces of cell debris -unicellular eurkaryotes such as amoebas and plasmodium use it to 'eat' bacteria

Question 38

Pseudopods

Answer 38

phagocytes produce sheet-like projections of these in order to capture the microbe

Question 39

Phagosome

Answer 39

formed when phagocytic vesicles contain an engulfed microbe, that which eventually fuses with a lysosome (sometimes referred to as a phagolysosome) in order to facilitate microbe death

Question 40

Pinocytosis and what are 4 characteristic of them

Answer 40

process in which eukaryotic cells ingest small pieces of their own plasma membrane along with small amount of extracellular fluid and small molecules 1. nonspecific 2. mostly carried out by vesicles formed from clathrin coated pits (pinocytic vesicles) 3. vesicles fuse wit endosomes 4. small molecules are often taken to be digested in lysosomes

Question 41

RME

Answer 41

Receptor-Mediated Endocytosis: macromolecules bind to complementary receptors on the cell surface and enter the cell as receptor-macromolecule complexes 1. allows for the uptake of molecules that can't move via a transporter 2. helps signaling receptors transmit the signal 3. more efficient uptake of specific molecules into the cell

Question 42

Transcytosis

Answer 42

when receptor proteins are sent to a different part of the plasma membrane, with their cargo bound3 di

Question 43

Mannose-6-phosphate

Answer 43

initial sugar group added to the ER in lysosomal targeting that results in Mannose-6-phosphate binding to the its specific receptors in the TRANS GOLGI recognize pattern and send them to endosome then lysosome (enzyme dissociates from receptor)

Question 44

Autophagy

Answer 44

process in which cells degrade dead or damaged organelles

Question 45

Autophagosome

Answer 45

a membrane bound organelle that then is enclosed by an additional membrane, which will then fuse with a lysosome