Midterm Cell Bio 2

Front 1

Translation

Back 1

Using RNA to make protein, occurs mainly in cytoplasm

Front 2

What kind of proteins are translated in the ER?

Back 2

Transmembrane proteins, Secreted proteins, resident proteins

Front 3

What are three different ways proteins can move from one compartment to another?

Back 3

1. Gated Transport

2. Protein Translocation

3. Vesicular Tranport

Front 4

Gated Transport

Back 4

Folded proteins can go from cytosol to nucleus via nuclear pore complex; move things in/out of nucleus

Front 5

Protein Translocation

Back 5

protein is unfolded and snakes through translocator into a new compartment (e.g. cytoplasm into ER during translation)

Front 6

Vesicular Transport

Back 6

membrane enclosed transport from one membrane compartment to another (e.g. Budding, pinching, fusion)

Front 7

How do proteins know where to go?

Back 7

Signals, signal sequences (recognized by receptors), aka amino acid sequence

—> embedded in proteins are detailed instructions that tell the cell where to go (aminonacid sequence)

Front 8

What does it mean for Lys- Arg to be adjacent to one another in an amino acid sequence?

Back 8

It is a Nuclear Localization signal (NLS)

Front 9

Explain how proteins made in ER

Back 9

signal sequence right at beginning if N terminus, then it will drag the entire thing, gets into ER, protein will be made in ER

Front 10

Why is it that a protein may change its localization to go inside the nucleus?

Back 10

The Nuclear localization signal could be hidden, upon being exposed, it can cause for conformational change and tell the protein to go to the nucleas

Front 11

Transcription factors

Back 11

Proteins that bind onto DNA to make RNA

Front 12

Transcription factors

Back 12

Proteins that bind onto DNA to make RNA

Front 13

If TF is off

Back 13

=outside if nucleus

Front 14

Transcription factors

Back 14

Proteins that bind onto DNA to make RNA

Front 15

If TF is on

Back 15

=inside of nucleus, induced to make RNA

Front 16

Nuclear Envelop Structure

Back 16

nuclear envelope defines nuclear compartment, consists of 2 membranes (inner and outer membranes are continuous

Front 17

NPC

Back 17

Nuclear pore complex, highly regulated aqueous channel through the nuclear envolope, allows slected molecules to move between the nucleus and cytoplasm

Front 18

What can easily diffuse through the NPC freely?

Back 18

small molecules (5kDa)

Front 19

How can large molecules go into nucleus if they can't fit in NPC?

Back 19

must be purposefully transported into the nucleus

Front 20

Nuclear Localization Signal

Back 20

signal sequence found in proteins destined for the nucleus from the cytosol through the nuclear pore complex; 1 or 2 short sequences of positively charged amino acids--> typically Lys or Arg

Front 21

What happens if there is a mutation in the NSL?

Back 21

prevention of import

Front 22

How was NSL tested?

Back 22

By mutating different parts of the amino acid sequence of protein, you will know which part instructs it to go to the nucleus--> if take away amino acid that are needded to go to the nucleus=the protein wont go to the nucleus

Front 23

Ran GTPase

Back 23

a GTPase, required for both import and export

Front 24

Where is Ran GAP located?

Back 24

in cytosol

Front 25

Where is Ran GEF located?

Back 25

In nucleus, anchored to chromatin

Front 26

GTPase

Back 26

GDP or GTP, drive import and export

Front 27

How is importin brought into the nucleus?

Back 27

Nuclear pore complex

Front 28

What is the result of hydrolysis of Ran-GDP?

Back 28

induces release of exportin and cargo

Front 29

Desribe the process of nuclear import

Back 29

Cargo--> NLS is in cargo--> binding of nuclear import receptor as it recognizes NLS--> taken into nucleus--> release of receptor--> (1) receptor goes back to cytosol--> receptor released--> Ran GDP disassociates from receptor--> Ran GDP +Pi --> receycled (2) Ran GTP makes sure cargo is released by importin--> cargo delivered to nucleus

Front 30

What is NF-AT?

Back 30

a transcription factor that has regulated import into nucleus when transcription is needed; needs to stay in cytoplas, a kinase (phosphorylates)

Front 31

What is Calcineurin?

Back 31

A phosphatase, binds and removes phosphates exposing the NLS and hiding NES

Front 32

When does nuclear envelope dissasemble?

Back 32

Mitosis

Front 33

Nuclear lamina

Back 33

meshwork of interconnected proteins, supporting inner membrane

Front 34

Lamins

Back 34

intermediate filament

Front 35

Nuclear import receptors are called?

Back 35

importins

Front 36

Nuclear export receptors are called?

Back 36

exportins

Front 37

Explain how importins and adaptor proteins work

Back 37

Adaptor proteins are used to bridge between NLS and import receptors--> allow for protein to be imported in

Front 38

Key enzyme that drives import and export?

Back 38

RanGTPase

Front 39

Signal sequence

Back 39

Amino acids within protein itself, drives destination of where the protein goes

Front 40

Double mebrane enclosed organelles, contain DNA and ribosomes, most proteins in these organelles are imported from the cytoplasm

Back 40

Mitochondria and chlorplasts

Front 41

Mitochondria enerrgy synthesis

Back 41

electron transport

Front 42

Chloroplasts energy synthesis is driven by

Back 42

Photosynthesis

Front 43

How are new mitochondria and chloroplasts are created?

Back 43

by preexisting organelles followed by fission

Front 44

What is an intermembrane space?

Back 44

space located between outer and inner membrane, is continuous with the cristae space

Front 45

What do compartments in mitochondrion allow for?

Back 45

the feneration of gradients within the mitochondrion, central to how they make ATP

Front 46

How many membranes do chloroplasts have?

Back 46

3 (inner membrane, thylakoid membrane, outer membrane)

Front 47

What does mitochondrial import rely on?

Back 47

signal sequences

Front 48

What facilitates transport in mitochondria?

Back 48

protein import channels and pores

Front 49

Name two translocators in mitochondria

Back 49

TOM complex, TIM complex

Front 50

TOM complex

Back 50

translocation of outer membrane, think of OXA

Front 51

TIM complex

Back 51

translocation of inner membrane, two different ones; think of SAM

Front 52

What do TIM and TOM complexes function as?

Back 52

can funcrtion as a receptor, others create the translocation channel

Front 53

SAM

Back 53

sorting and assembly machinery; helps insert/ fold membrane proteins into the outer membrane

Front 54

OXA

Back 54

cytochrome oxidase activity; mediates insertion of protein into the inner membrane