Biology 2382B Lecture Notes - Lecture 4: Calnexin, Asparagine, Oligosaccharyltransferase

36 views7 pages

sangriapanda814

23 Aug 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Section 4 objectives protein synthesis and transport protein targeting typical mammalian cell: 10,000 proteins, must be localized correctly newly made proteins must be directed to the correct destination. Targeting: direct proteins to the right destinations (organelles, during or after synthesis. Sorting: direct proteins to the secretory pathway (er, golgi, lysosomes) General principles of protein synthesis, targeting and sorting. Basic mechanisms of protein targeting to the membranes of organelles are common: signal sequence receptor for the signal sequence translocation channel: translocation = transport from one thing to another source of energy. Er: structure and function uninterrupted membranous tubules and vesicles separated from the cytoplasm. Rer has ribosomes on the tubules (cisterna: cisterna are stacked. *the lumen of the er is a part of the secretory pathway. Stringing concepts together identify cellular features by microscopy, isolate and homogenize them to free organelles sucrose density-gradient centrifugation of homogenate allows for isolation of microsomes and ribosomes. Sds-page is used to identify newly translated proteins.

Related Questions

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

ochrecoyote721

Biology 2382B Lecture Notes - Lecture 4: Calnexin, Asparagine, Oligosaccharyltransferase

Document Summary

Get access

Related Documents

Biology 2382B Lecture Notes - Lecture 4: Sucrose, Peptide, Dolichol

Biology 2382B Lecture Notes - Lecture 4: Secretion, Membrane Transport Protein, Golgi Apparatus

Biology 2382B Lecture Notes - Lecture 13: Secretion, Secretory Protein, N-Terminus

Related Questions