BIOL 2020 Lecture Notes - Lecture 10: Phosphotransferase, Autophagosome, Mannose

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blushwoodchuck89

6 Oct 2015

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Coated vesicles; membrane coat that is made up of proteins that are associated with the cytoplasmic side of the membrane: proteins help form the vesicles, they also select the proteins that need to be moved to somewhere else, copii forward from er to ergic and golgi, copi retrograde from ergic and golgi to the er and from trans golgi to cis, clathrin coated tgn to endosomes and lysosomes; plasma membrane to cytoplasmic compartments. Gtp (cid:224) undergoes a conformational change (cid:224) inserts into er membrane (cid:224) promotes a binding of copii proteins to bind to membrane (cid:224) copii recognizes trans membrane proteins and are incorporated into the vesicle membrane: some trans membrane proteins are receptors for cargo proteins, er resident proteins are left behind as they don"t fit the receptors inserted into the vesicle, vesicle buds off and leaves the er (cid:224) copii coat has to be removed when vesicle reaches destination, gtp activates the copii coat falling off.

Related Questions

29 Most proteins destined to enter the endoplasmic reticulum _________.

(a) are transported across the membrane after their synthesis is complete.

(b) are synthesized on free ribosomes in the cytosol.

(d) are keep binding to Signal recognition particle (SRP) while they are translated.

30 Which of the following choices reflects the appropriate order of locations through which a protein destined for the plasma membrane travels?

(a) lysosome â endosome â plasma membrane

(b) ER â lysosome â plasma membrane

(d) ER â Golgi â plasma membrane

31 Which of the following statements about vesicle budding from the Golgi is false?

(a) COPII can initiate vesicle budding on Golgi membrane.

(b) Some vesicles budded from Golgi membranes move towards ER.

(d) Clathrin molecules act at the cytosolic surface of the Golgi membrane.

32 Which of the following statements is false?

(a) The signal sequences on mitochondrial proteins are first bound to translocator on outer membrane after translation.

(b) Most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria.

(c) Chaperone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes.

(d) Mitochondrial proteins cross the membrane in their unfolded state.

orangeplatypus673

1. The histones that form the core of the nucleosome get into the nucleus by which of the following?

a) Passive diffusion through nuclear pores

b) Selective and facilitated active transport through nuclear pores

c) Ribosomes located in the nucleus synthetize histones in the nucleus

d) Histones are made at the ER membrane and then diffuse to the nucleus

2. Membrane proteins that belong to the golgi, lysosome, or plasma membrane first pass through which organelle before reaching their final subcellular destination?

a) The golgi apparatus

b) The smooth ER

c) The nucleus

d) The ER membrane

e) The ER lumen

3. Where in the cell would a ribosomal protein be located if it has had its nuclear export signal inactivated (non-functional or non-existent).

a) The protein would be found in the ER lumen

b) The protein would remain in the nucleus

c) The protein would be secreted

d) The protein would remain in the cytoplasm

e) The protein would be in the ER membrane

4. Where would be the final destination of a protein if it contained a NLS anywhere in the protein sequence (and which is exposed to the cytoplasm after protein folding) but also contained an ER signal sequence at the carboxy terminus?

a) The ER lumen

b) The nucleus

c) The cytoplasm

d) The inner nuclear membrane

e) The ER membrane

5. The sequence K-D-E-L serves as a retention/retrieval signal for ER proteins.

a) True

b) False

6. The following are true for both cell membrane proteins and secretory proteins EXCEPT?

a) Precursors of the mature proteins contain signal sequence.

b) Both types of proteins contain stop-transfer sequences

c) Both types of proteins enter the ER while being synthetized

d) Both types of proteins pas through the golgi apparatus

e) Both are carried by clatherin-coated vesicles

7. If you isolate a regulated secreted protein from a secretory/storage vesicle and inject it into the cytosol, is will?

a) Be secreted through channels in the plasma membrane

b) Be taken up into secretory vesicle and secreted

c) Remain in the cytosol until it is degraded

d) Be taken up into the rough ER and follow the secretory pathway

goldmanatee250

QUESTION 30

The function of centrosome is:

	1.	Microtubule initiation and organization in animal cells
	2.	Organization of thin filaments
	3.	Depolymerization of microtubules
	4.	Organization of intermediate filaments

2.5 points

QUESTION 31

The destinations of proteins synthesized on "free" ribomsomes include:

	1.	Endoplasmic reticulum
	2.	Nucleus
	3.	Mitochondria
	4.	Lysosomes

2.5 points

QUESTION 32

Microtubules can be assembled and disassembled quickly in response to the cellular changes is because:

	1.	Cells synthesize tubulin proteins very fast.
	2.	Cells can turn other cytoskeletal filaments into microtubules
	3.	Microtubules have an instable plus end and microtubules are probably organized by weak non-covalent interactions
	4.	The motor proteins of microtubules can organize the microtubules in response to the cellular changes

2.5 points

QUESTION 33

Both signal recognition particle and a translocon in rough endoplasmic reticulum membrane can recognize and bind to the signal sequence of a secretory protein, so they play the exact same role during protein co-translational translocation.

True

False

2.5 points

QUESTION 34

Rough endoplasmic reticulum is so named is because:

	1.	It has many proteins associated with its surface.
	2.	It has ribosomes associated with its cytosolic surface.
	3.	It is associated with nuclear membrane.
	4.	It has vesicles budding off its surface.

2.5 points

QUESTION 35

The membrane vesicles that transport materials between membrane compartments have a protein coat. The protein coat has similar functions in different vesicles. These functions include:

	1.	Help the enclosed material fold correctly.
	2.	Help degrade the protein in the vesicles
	3.	Maintain the internal pH of the vesicles
	4.	Function as mechanical device to form a vesicle and select the components to be carried by a vesicle.

2.5 points

QUESTION 36

Lysosomes are important for:

	1.	Receptor-mediated endocytosis.
	2.	Breaking down foreign particles brought into the cells by endosomes
	3.	Regulating the process of organelle turnover.
	4.	Protein trafficking between membrane compartments

2.5 points

QUESTION 37

Which of the following is correct about membrane biosynthesis?

	1.	Membranes are synthesized in Golgi Complex.
	2.	Membranes arise from preexisting endoplasmic reticulum membranes.
	3.	Membranes are synthesized on ribosomes.
	4.	Membranes of all organelles have the same composition of proteins and lipids, since they all originate from endoplasmic reticulum.

2.5 points

QUESTION 38

During skeletal muscle contractions, the shortening of the muscle fibers is because of:

		The shortening of the thin and thick myofilaments.
		The shortening of the cytoskeletal filaments.
		The kinesin proteins moving over microtubules.
		The actin and myosin filaments sliding over each other.

2.5 points

QUESTION 39

The assembly and disassembly of microtubules is regulated by rate of growth and shrinkage of the plus end.

True

False

2.5 points

QUESTION 40

The functions of Golgi complex include:

	1.	O-linked oligosaccharides and most of a cellâs complex polysaccharides are assembled in Golgi complex
	2.	Cis Golgi complex sorts proteins
	3.	Trans Golgi complex segregates proteins in different types of vesicles for dilevery.
	4.	N-linked oligosaccharides are further processed in Golgi complex

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BIOL 2020 Lecture Notes - Lecture 10: Phosphotransferase, Autophagosome, Mannose

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