Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BMSC 220 > Lecture #11 > Flashcards

Lecture #11 Flashcards

1
Q

Sorting and transport of lysosomal enzymes utilizes ______-coated vesicles

A

clathrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lysosomal proteins are tagged in the ___-Golgi with phosphorylated mannose residues

A

cis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Tagged lysosomal enzymes are recognized and captured by ? (MPRs), which are bound by coat proteins

A

mannose 6-phosphate receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Clathrin-coated vesicles contain:

An outer lattice composed of _____.
An inner ____ composed of GGA adaptor proteins, which interacts with clathrin, MPR, and G-protein.
The __-______ Arf1-GTP, used to initiate membrane curvature and recruit adaptors.

A

clathrin, shell, G-protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Secreted proteins which are released by regulated secretion may form selective aggregates that eventually become contained in large, densely packed ______ _______

A

secretory granules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

_____ ______ are stored in the cytoplasm until their contents are released following stimulation of the cell by a hormone or nerve impulse

A

Mature granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Plasma membrane proteins may use constitutive secretion or one of two TGN membrane carrier systems depending if the cell is _______ or not

A

polarized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The steps that occur between vesicle budding and vesicle fusion include:

  1. Movement of the vesicle toward the ______ ______ compartment, mediated largely by microtubules and their associated motor proteins.
  2. Tethering vesicles to the _______ _______, mediated by a diverse collection of “tethering” proteins.
  3. Docking vesicles to the target compartment, vesicle and target compartment membranes come into close contact via interaction between ______ ______ of the two membranes.
  4. _______ between vesicle and target membranes.
A

specific target, target compartment, integral proteins, Fusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

_____ are a family of small G proteins which cycle between an active GTP bound state and an inactive GDP bounds state

A

Rabs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

GTP-bound Rabs associate with membranes by a _____ _____. ________ Rabs become associated with different membrane compartments.

A

lipid anchor, Different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

_______ constitute a family of proteins localized to specific subcellular compartments; are integral proteins that bring the vesicle and target compartment in close contact.

A

SNAREs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

__‐SNAREs are found in transport vesicles and __‐SNAREs are located in the target compartments

A

v, t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In nerve cells, plasma membrane contains ___ t-SNAREs (syntaxin and SNAP-25), the synaptic vesicle membrane contains a _____ v-SNARE (synaptobrevin)

A

two, single

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T- and v-SNARE molecules interact to form ____-stranded bundles, each with four ____ helices. These parallel helices zip together to form a tightly interwoven complex that pulls the two _____ lipid bilayers into very close association.

A

four, alpha, apposing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Contacts between vesicle and plasma membranes lead to formation of _____ ____

A

fusion pore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The _____ part of the vesicle membrane becomes the outer surface of the PM, and the ________ part becomes part of the inner surface of the PM

A

luminal, cytosolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Extracellular vesicles can move through the body unnoticed by the _______ system passing through difficult biological barriers. The downside is their short half-life before ________.

A

immune, phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Lysosomal enzymes (acid _______) have optimal activity in the acidic lumen

A

hydrolases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Low pH is maintained by a proton pump present in the membrane of the _______

A

lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Single-celled organisms and phagocytic white blood cells digest ingested materials by fusing _________ and ________

A

phagosomes, lysosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Lysosomes play a role in the regulated process of organelle turnover, known as _______

A

autophagy

22
Q

A phagophore envelops an organelle to produce a double-membrane sequestering vesicle called an ___________.

A

autophagosome

23
Q

This fuses with a lysosome, generating an ___________, both the inner membrane of the autophagosome and the enclosed contents are degraded.

A

autolysosome

24
Q

Autophagy benefits:
Helps protect an organism against _________ threats (i.e., abnormal protein aggregates or invading bacteria).
May play a role in the _______ of certain types of cancers and slowing the body’s aging process.

A

intracellular, prevention

25
Q

__________ is primarily a process by which the cell internalizes cell-surface receptors and bound extracellular ligands.

__________ is the uptake of particulate matter.

A

Endocytosis, Phagocytosis

26
Q

Endocytosis can be divided broadly into two categories:

  1. ? – non-specific uptake of extracellular fluid.
  2. ? – brings about the uptake of specific extracellular macromolecules following binding to receptors on the surface of the plasma membrane.
A

Bulk phase endocytosis (pinocytosis)
Receptor mediated endocytosis (clathrin mediated endocytosis)

27
Q

Substances that enter the cell through clathrin-mediated RME become bound to _____ pits on the plasma membrane. Clathrin-coated regions invaginate into the cytoplasm and then pinch free of the ________.

A

coated, cytoplasm

28
Q

Each clathrin molecule has 3 heavy chains and 3 light chains, joined together at the center to form a three-legged assembly called a _______.

A

triskelion

29
Q

Triskelions overlap and each leg of extends outward along two edges of a _______. Each vertex (the highest point) contains a ______ of one of the component triskelions.

A

polygon, center

30
Q

Coated vesicles contain adaptors between the clathrin lattice and the surface of the vesicle facing the cytosol such as _____

A

AP2

31
Q

___ adaptors contain multiple subunits having different functions, and engage cytoplasmic ____ of specific receptors to select bound cargo molecules, and bind and recruit the _______ molecules of the overlying lattice.

A

AP2, tails, clathrin

32
Q

Coated vesicles may contain two dozen different _________ proteins that form a dynamic network of interacting molecules. These proteins have roles in cargo recruitment, coat assembly, membrane bending and invagination, interaction with cytoskeletal components, vesicle release, and membrane uncoating.

A

accessory

33
Q

_______ is a G protein required for the fission of the vesicle from the membrane on which it forms. It self-assembles into a _____ collar around the neck of an invaginated coated pit.

A

Dynamin, helical

34
Q

AP2 adaptors normally exist in the cytosol in a ______ conformation. Binding of AP2 complex to PI(4,5)P2 (phosphoinositide) causes a _________ change in AP2. The AP2 cargo binding site becomes _________, allowing it to interact with specific membrane receptors.

A

locked, conformational, exposed

35
Q

After internalization, vesicle-bound materials are transported in vesicles and tubules known as ________.

A

endosomes

36
Q

_____ endosomes are located near the periphery of the cell. It sorts materials and sends bound ligands to the ____ endosomes

A

Early, late

37
Q

Differences between early and late endosomes:
- ____ endosome is more acidic
- _____ endosomes are located in the periphery of the cytoplasm. ____ endosomes are moving from the periphery of the cytoplasm and perinuclear area.
- ____ endosomes fuse with lysosomes.

A

late, Early, Late, Late

38
Q

Low-density lipoproteins (LDLs) are a complex of ________ and _______

A

cholesterol, proteins

39
Q

LDL receptors are transported to the plasma membrane and bound to a _______ pit; the are taken up by RME and taken to the _______, releasing the ________ for use by the cells.

A

coated, lysosomes, cholesterol

40
Q

Phagocytosis is carried out by cells specialized for the uptake of relatively _____ particles.

A

large

41
Q

The folds fuse to produce a vacuole (_______) that pinches off inwardly from the plasma membrane and fuses with a lysosome (_________)

A

phagosome, phagolysosome

42
Q

Mammals have “________” phagocytes, e.g., macrophages and neutrophils, that phagocytize invading organisms, damaged and dead cells

A

professional

43
Q

_______ are small, membrane-enclosed organelles that contain enzymes involved in a variety of metabolic reactions, including several aspects of energy metabolism

A

Peroxisomes

44
Q

The nucleus, mitochondria, chloroplasts, and peroxisomes import proteins through one or more _____ boundary membranes.

A

outer

45
Q

As in the case of the RER, proteins that are imported by these organelles contain amino acid sequences that serve as _______ that are recognized by receptors at the organelle’s outer membrane.

A

addresses

46
Q

Unlike RER, which generally imports its proteins __________, the proteins of these other organelles are imported ___________, following their complete synthesis on free ribosomes in the cytosol

A

cotranslationally, posttranslationally

47
Q

Peroxisomes have two subcompartments in which an imported protein can be placed: ?

A

the boundary membrane and the internal matrix.

48
Q

Peroxisomal proteins possess a peroxisomal targeting signal, either a PTS for a ? or an mPTS for a ?

A

peroxisomal matrix protein, peroxisomal membrane protein.

49
Q

PTS receptors bind to peroxisome-destined proteins in the ______ and shuttle them to the surface of the peroxisome, where they can enter the organelle

A

cytosol

50
Q

________ proteins will unfold the proteins before their entrance into the mitochondria

A

Chaperones

51
Q

The outer mitochondrial membrane includes a protein-import complex (____ _______) which includes a receptor and channel

A

TOM complex

52
Q

Proteins destined for the inner mitochondrial membrane engage with another protein-import complex (____ _______)

A

TIM complex

BMSC 220 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions