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 cellรขยยs 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
