MBB 231 Lecture Notes - Lecture 13: Chronic Obstructive Pulmonary Disease, Catalase, Mannose

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burgundyferret646

9 Dec 2015

School

Simon Fraser University

Department

Molec Biol & Biochem

Course

MBB 231

Professor

Ingrid Northwood

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Document Summary

There are 2 major types of transporting materials across the plasma membrane: exocytosis, endocytosis. Proteins in a vesicle are released to the exterior of the cell as the membrane of the vesicle fuses with the plasma membrane. A combination of endocytosis and exocytosis is known as transcytosis. The process by which the cell internalizes external material. Most vesicles that are involved in lipid or protein transfer are known as coated vesicles, due to the presence of a. There are 3 major types of coated proteins: copi (coated protein i): Functions in facilitating the transport of proteins from the golgi complex to the endoplasmic. In addition, copi functions in the bidirectional transport between golgi complex cisternae. Do not require gtp hydrolysis to undergo exocytosis / endocytosis: copii (coated protein ii): Functions in facilitating the transport of proteins from the endoplasmic reticulum to the golgi. Do not require gtp hydrolysis to undergo exocytosis / endocytosis.

Related Questions

1) how does the timing and location of Arf1-GTP hydrolysis contribute the transport of COPI coated vesicles?

2) Consider cargo proteins that are destined for secretion to the extracellular space. For each of the following pairs of mutations or conditions, predict where the cargo will end up (ex. in the cytoplasm, a specific organelle, transport vesicles, multiple places, extracellular space) for: (i) & (ii) Each individual condition; & (iii) The combination of both.

A.(i) Normal Sar1 is mutated so that it hydrolyzes GTP immediately after binding GTP.

(ii)The signal recognition particle is mutated to be unable to bind to the SRP receptor.

(iii)Both

B.(i) A mitochondrial signal sequence is added to the C-terminus of the cargo protein.

(ii)v-SNAREs on COPII coated vesicles are mutated to be unable to bind t-SNAREs

(iii)Both

C. (i) COPII coat proteins are mutated so they donât bind to the ER membrane.

(ii)COPI coat proteins are mutated so they donât bind to the Golgi membrane.

(iii)Both

D.(i) Normal Sar1 is mutated so it binds tightly to GDP and cannot exchange it for GTP. (This leads to Sar1*-GDP being the only form of the protein in the cell.)

(ii) A transmembrane domain is added to the cargo protein.

(iii)Both

The vesicles that transport materials from donor membranes to acceptor membranes include:

	1.	COP-II coated vesicles
	2.	COP-III coated vesicles
	3.	COP-I coated vesicles
	4.	Clathrin coated vesicles

2.5 points

QUESTION 11

During skeletal muscle contraction, the roles of ATP include:

	1.	ATP is not required for forming the crossbridges between myosin and actin filaments.
	2.	ATP is utilized as a structural linker to mediate the interaction between myosin and actin filaments
	3.	Hydrolysis of ATP provides energy for myosin head to move along actin filaments and the binding of ATP to myosin head allows the detachment of myosin fromactin filaments.
	4.	ATP binds to actin filaments to drive the power stroke of myosin head.

2.5 points

QUESTION 12

One of the functions of smooth endoplasmic reticulum is

	1.	Synthesizing steroid hormone in the endocrine cells of the gonad and adrenal cortex
	2.	Serves as the starting point of the biosynthetic pathway
	3.	Synthesizing secretory proteins
	4.	Degrading cell debris

2.5 points

QUESTION 13

The function of COP-II coated vesicles is mainly:

	1.	Transporting materials from endosomes to Golgi complex
	2.	Moving materials from the ER to the ERGIC and Golgi complex.
	3.	Transporting materials from Golgi complex back to endoplasmic reticulum.
	4.	Involved in receptor-mediated endocytosis.

2.5 points

QUESTION 14

Which of the following processes is completed in rough endoplasmic reticulum?

	1.	Chaperones help misfolded proteins fold correctly.
	2.	Proteins that target to nucleus are synthesized in rough endoplasmic reticulum.
	3.	O-linked glycosylation occurs in rough endoplasmic reticulum.
	4.	Misfolded proteins are destructed in rough endoplamic reticulum.

2.5 points

QUESTION 15

Kinesin is the motor protein that coorporates with microtubules. It has the following functions:

	1.	It uses GTP as energy source.
	2.	It can hydrolyze ATP and use the energy to drive cargo along microtubules from minus end to plus end.
	3.	It has a globular head that can act as GTPase
	4.	The tail of kinesin is more diverse and binds to cargo

2.5 points

QUESTION 16

For correct segregation and trafficking, lysosomal proteins are tagged in the cis-Golgi with phosphorylated mannose residues, and then the tagged lysosomal enzymes are recruited to clathrin coated vesicles by mannose 6-phosphate receptors.

True

False

2.5 points

QUESTION 17

The process that specialized cells, such macrophages, engulf relatively large particles is:

	1.	Called pinocytosis
	2.	Called phagocytosis
	3.	Mediated by COP-II coated vesicles
	4.	Called autophagy

2.5 points

QUESTION 18

Proteins synthesized on rough endoplasmic reticulum and smooth endoplasmic reticulum are imported co-translationally to their destinations

True

False

2.5 points

QUESTION 19

Treatment of cells with a drug that promotes microtubule disassembly disperses Golgi complex into separate stacks of membrane compartments, suggesting that:

	1.	Golgi complex is made of microtubules.
	2.	Microtubules are important for the organization of Golgi complex.
	3.	Microtubules are transported into Golgi complex
	4.	Golgi complex is composed of tubulin proteins

2.5 points

QUESTION 20

Which of the following is correct about signal sequence of a secretory protein?

	1.	It is an âaddress codesâ for protein trafficking pathways
	2.	It is usually located at the C-terminus.
	3.	It targets the ribosome and the protein that is being synthesized to endoplasmic reticulum.
	4.	It is removed in Golgi complex.

apricotgrasshopper117

1) Which of the following statements about transport into the mitochondria is FALSE?

a) The signal sequence on proteins destined for the mitochondria is recognized by a receptor protein in the outer membrane of the mitochondria.

b) Proteins that are transported into the mitochondria are unfolded as they are being transported.

c) Transport of proteins into the mitochondria requires SRP and the SRP receptor.

d) After a protein is made in the cytosol it must move through two protein translocators to reach the inner mitochondrial matrix.

2.Which coat protein is involved in vesicle formation during endocytosis â vesicle forms from plasma membrane and fuses with endosomes?

a) COPI
b) COPII

c) v-SNARES d) Clathrin

3. Which of the following statements about vesicular membrane fusion is TRUE?

a) Membrane fusion does not always immediately follow vesicle docking.

b) The interactions of the v-SNAREs and t-SNAREs pull the vesicle membrane and the target organelle together so that their lipids can intermix.

c) NSF and SNAP disassemble the SNARE complex so the SNAREs can be recycled.

d) All of the above are true.

MBB 231 Lecture Notes - Lecture 13: Chronic Obstructive Pulmonary Disease, Catalase, Mannose

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