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BIO 344 Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
How do proteins get moved between the nucleus and cytosol
Ans: Nucleus- Gated transport
Mitochondria- trans membrane transport
ER- trans membrane transport then to vesicle transport to get
to golgi
What are nuclear pore complexes (NPC)
Ans: Large structure that perforate the nuclear envelope and
transports macromolecules bidirectionally in ER
What is a nuclear import receptor
Ans: initiates nuclear import, cytosolic proteins that bind the
signal on the protein to be transported to the NPC then to
cytsol
What molecule delivers energy to facilitate transport of large proteins
into the nucleus
Ans: GTPase Ran
All rights reserved © 2025/ 2026 |
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Describe the sub compartments of mitochondria and chloroplasts
Ans: Mito- inner and outer space with matrix in center.
Chloroplast- Thylakoid space and stroma in middle
What are protein translocators
Ans: mediate protein translocation across mitochondria
TOM- outer membrane
TIM- inner membrane
Why does it matter that the mitochondrial signal sequence for protein
import forms an alpha helix? Describe the properties of this alpha helix
Ans: When folded as alpha helix, it is amphiphillic. One side
alpha helix is polar, other side charged
Describe how proteins are imported into mitochondrial matrix
Ans: -Cross the membrane separately or both at once.
-Bind to their signal sequences
-TOM complex binds the signal sequence
-the interacting proteins strip off to prevent folding
All rights reserved © 2025/ 2026 |
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What molecule provides energy for transport of proteins into the
mitochondria
Ans: ATP hydrolysis
How do proteins get directed to the membrane space?
Ans: -Matrix space has to cross two different spaces at once
- has to have separate signaling sequence to be transferred to
the inter membrane space
What is the difference between smooth ER and rough ER
Ans: Smooth- make phospholipid fatty acids, no ribosomes,
Rough- is rough, Yes ribosomes, where translation and
synthesis of proteins occur
Where does protein synthesis start
Ans: Protein synthesis begins in the cytosol in free ribosomes
How does a protein get directed to the ER
Ans: The signal sequence binds to the Signal-Recognition
Particle(SRP) which is possible due to the crystal structure of
the SRP protein( accommodates many shapes, sizes and
All rights reserved © 2025/ 2026 |
BIO 344 Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
How do proteins get moved between the nucleus and cytosol
Ans: Nucleus- Gated transport
Mitochondria- trans membrane transport
ER- trans membrane transport then to vesicle transport to get
to golgi
What are nuclear pore complexes (NPC)
Ans: Large structure that perforate the nuclear envelope and
transports macromolecules bidirectionally in ER
What is a nuclear import receptor
Ans: initiates nuclear import, cytosolic proteins that bind the
signal on the protein to be transported to the NPC then to
cytsol
What molecule delivers energy to facilitate transport of large proteins
into the nucleus
Ans: GTPase Ran
All rights reserved © 2025/ 2026 |
, Page |2
Describe the sub compartments of mitochondria and chloroplasts
Ans: Mito- inner and outer space with matrix in center.
Chloroplast- Thylakoid space and stroma in middle
What are protein translocators
Ans: mediate protein translocation across mitochondria
TOM- outer membrane
TIM- inner membrane
Why does it matter that the mitochondrial signal sequence for protein
import forms an alpha helix? Describe the properties of this alpha helix
Ans: When folded as alpha helix, it is amphiphillic. One side
alpha helix is polar, other side charged
Describe how proteins are imported into mitochondrial matrix
Ans: -Cross the membrane separately or both at once.
-Bind to their signal sequences
-TOM complex binds the signal sequence
-the interacting proteins strip off to prevent folding
All rights reserved © 2025/ 2026 |
, Page |3
What molecule provides energy for transport of proteins into the
mitochondria
Ans: ATP hydrolysis
How do proteins get directed to the membrane space?
Ans: -Matrix space has to cross two different spaces at once
- has to have separate signaling sequence to be transferred to
the inter membrane space
What is the difference between smooth ER and rough ER
Ans: Smooth- make phospholipid fatty acids, no ribosomes,
Rough- is rough, Yes ribosomes, where translation and
synthesis of proteins occur
Where does protein synthesis start
Ans: Protein synthesis begins in the cytosol in free ribosomes
How does a protein get directed to the ER
Ans: The signal sequence binds to the Signal-Recognition
Particle(SRP) which is possible due to the crystal structure of
the SRP protein( accommodates many shapes, sizes and
All rights reserved © 2025/ 2026 |
