Unit 2 Terms

Question 1

sorting signals

Answer 1

• Found in amino acid sequence of protein.
• New proteins must go from a ribosome in the cytosol to the organelle where it functions (knows where to go due to this signal)

Question 2

electron microscopy

Answer 2

Helps give snapshots of the secretory pathway

RER → Golgi → Vesicles → Membrane

Question 3

Sec proteins

Answer 3

• main proteins involved in protein trafficking
• discovered in yeast

Question 4

Ribosomes initiate translation in the __________.

Answer 4

cytosol

Question 5

Coats (for vesicles)

Answer 5

geometrical structures that assemble into vesicle cages

Question 6

Rab Proteins vs SNARE proteins

Answer 6

Rab:
Guide Transport Vesicles to Their Target Membrane

SNARE:
Mediate Membrane Fusion by putting the membranes in close proximity

Question 7

budding yeast Saccharomyces cerevisiae

Answer 7

Has a system of dispersed cisternae (not stacked like usual)

Question 8

fluorescent live imaging (transport in Golgi)

Answer 8

• Golgi protein fused to GFP (green fluorescent protien)
• Track GFP through the Golgi
• See processes in real time and in different colors
• Fluorescence microscopy of a single cisternae shows its maturation dynamics

Question 9

linear signal sequences

Answer 9

Sorting signals for protein translocation into organelles

Question 10

nuclear envelope

Answer 10

two concentric membranes, perforated by nuclear pore complexes

Question 11

Unstructured proteins

Answer 11

lack a well-structured three-dimensional fold

Question 12

The concentration of Ran bound to GTP provides _______ and _____________.

Answer 12

Energy, directionality

Question 13

Microtubule nucleation

Answer 13

process in which several tubulin molecules interact to form a microtubule seed

Question 14

Axonal transport of organelles

Answer 14

Neurons transport vesicles with neurotransmitters to the synapse

Question 15

Kinesin-binding ________ prevents Kinesin-_________ binding

Answer 15

Protein, microtubule

Question 16

G actin and F actin

Answer 16

globular actin, filamentous actin

Question 17

_______ is a drug that stabilizes F-actin. Examples? F-actin structures usually are linked to the ______.

Answer 17

Phalloidin
Ex: death cap mushrooms

membrane

Question 18

Cells dynamically change the activity and localization of ________________ to assemble complex _____________.

Answer 18

actin-binding proteins, actin structures

Question 19

In ______ cells, _______ are the pioneers at the leading edge which _____ the environment for cues.

Answer 19

Migrating, filopodia, probe

Question 20

Stretch activation

Answer 20

intrinsic length-sensing mechanism that allows muscles to function with an autonomous regulation (bypassing calcium).

Ex: in flies

Question 21

Tropomyosin vs troponin

Answer 21

Tropomyosin
- elongated protein that binds along the groove of the actin filament helix.

Troponin
- a complex of three polypeptides

Question 22

epithelia

Answer 22

• cells are tightly bound together into sheets
• it’s an epithetical tissue (lining of the gut or the epidermal covering of the skin)
• selective permeability barriers

Question 23

Typical cadherins vs atypical Cadherins

Answer 23

Typical Cadherins = Homophilic
Atypical Cadherins = heterophilic.

Question 24

planar cell polarity

Answer 24

The collective alignment of cell polarity across the tissue plane (phenomenon)

Question 25

myotendinous junctions

Answer 25

similar to focal adhesions but stronger and permanent

Question 26

tight junctions (Cadherins)

Answer 26

act as ‘fences’ against transmembrane diffusion, lock the asymmetry in place.

Question 27

Baz/Par-3

Answer 27

is a scaffold for cadherins, which then propagate the polarity in an epithelia so that all the cells are polarized equally.

Question 28

The __________ proteins are the minimal ________ complex

Answer 28

Transmembrane, asymmetric

Question 29

Non-cell autonomous effect

Answer 29

polarity propagates through the tissue

Question 30

The ________ cellular localization of the ____ proteins is driven by a __________ but not always.

Answer 30

Asymmetric, core, global cue

Question 31

Global pathway vs Core pathway

Answer 31

Global - convert expression gradient into small asymmetries Core - amplify the small asymmetries into clear cellular structures

Question 32

visible light spectrum

Answer 32

segment of the electromagnetic spectrum that the human eye can view

Question 33

Photoactivatable fluorescent proteins

Answer 33

are fluorescent proteins that display unique changes in their spectral properties upon exposure to a specific wavelength of light

Question 34

MS2/MCP system

Answer 34

allows tracking RNA molecules

Question 35

Dicer (a nuclease enzyme)

Answer 35

cleaves the dsRNA into small fragments (of approximately 23 nucleotide pairs) called small interfering RNAs (siRNAs).

Question 36

RNA-induced silencing complex (RISC)

Answer 36

a complex of ribonucleic acid and RNA-binding proteins (composed of Argonaute, RNA and etc)

Question 37

A short hairpin RNA shRNA

Answer 37

an artificial RNA molecule with a hairpin turn that mimics a dsRNA molecule