Log in
HomeStudy Guides420,000CA160,000

Biology 2382B Study Guide - Midterm Guide: Stress Fiber, Kinesin, Post-Translational Modification

143 views30 pages
emeraldhorse370
24 Apr 2018
School
Western University
Department
Biology
Course
Biology 2382B
Professor
Robert Cumming

For unlimited access to Study Guides, a Grade+ subscription is required.

Document Summary

The cytoskeleton is an intricate network of protein filaments that extend throughout the cytoplasm. Three types of cytoskeletal proteins: microfilaments (smallest = actin) , microtubules (largest), intermediate filaments (intermediate in size): memorize numbers. Sub cytoskeletal components can form a network of proteins with certain functions, other components can act as a rod that poke things. Some are used as ropes which can pull things (networks, vs ropes vs rods). Cytoskeleton roles: organelle/protein trafficking, mitosis/cytokinesis, muscle contraction. Important to remember that biological molecules are 3-d and take up space. Important to know that cell is not empty. Everything is full there is no empty space in a cell. Polymer of and b tubulin: monomers 55kda each, (cid:271) di(cid:373)er is (cid:271)asi(cid:272) (cid:862)su(cid:271)u(cid:374)it(cid:863, have polarity. 25 nm diameter, up to 100s of m long. Different isoforms of tubulin main forms of microtubules are alpha and beta. Alpha beta dimer is the basic building block (not monomer).

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers

Related Documents

Biology 2382B Lecture 9: Damjanovski Section 1 - Cytoskeleton
magentacrocodile542
Biology 2382B Lecture Notes - Lecture 1: Spindle Apparatus, Biological Membrane, Cell Migration
lavenderbear991
Biology 2382B Lecture Notes - Lecture 9: Cell Membrane, Chemotherapy, Exocytosis
sapphirebear815

Related Questions

Hello everyone, i'm working on thesepractices multiple choices for my finals. If you know any of theseanswer, please help. i appreciate your time and your help. Thankyou!!!

1. ___ Which of thefollowing statements about the cytoskeleton is false?

(a) The cytoskeletonis made up of three types of protein filament.

(b) The bacterialcytoskeleton is important for cell division and DNAsegregation.

(c) Protein monomersthat are held together with covalent bonds form cytoskeletalfilaments.

(d) The cytoskeleton of acell can change in response to the environment.

2. ___ Which of thestatements below about intermediate filaments is false?

(a) They can stayintact in cells treated with concentrated salt solutions.

(b) They can befound in the cytoplasm and the nucleus.

(c) They can beanchored to the plasma membrane at cell-cell junction.

(d) Each filament is about10 ?m in diameter.

3. ___ Keratins,neurofilaments, and vimentins are all categories of intermediatefilaments. Which of the following properties below is nottrue of these types of intermediate filaments?

(a) They strengthencells against mechanical stress.

(b) Dimers associateby noncovalent bonding to form a tetramer.

(c) They are foundin the cytoplasm.

(d) Phosphorylation causesdisassembly during every mitotic cycle.

4. ___ Which of thefollowing statements about microtubules is true?

(a) Motor proteinsmove in a directional fashion along microtubules by using theinherent structural polarity of a protofilament.

(b) The centromerenucleates the microtubules of the mitotic spindle.

(c) Becausemicrotubules are subject to dynamic instability, they are used onlyfor transient structures in a cell.

(d) ATP hydrolysis by atubulin heterodimer is important for controlling the growth of amicrotubule.

5. ___ Thehydrolysis of GTP to GDP carried out by tubulin molecules________________.

(a) provides theenergy needed for tubulin to polymerize

(b) occurs becausethe pool of free GDP has run out

(c) tips the balancein favor of microtubule assembly

(d) allows the behavior ofmicrotubules called dynamic instability

6. ___ The microtubulesin a cell form a structural framework that can have all thefollowing functions except which of the following?

(a) holding internalorganelles such as the Golgi apparatus in particular positions inthe cell

(b) creating longthin cytoplasmic extensions that protrude from one side of thecell

(c) strengtheningthe plasma membrane

(d) moving materials fromone place to another inside a cell

7. ___ Which of thefollowing statements about organellar movement in the cell isfalse?

(a) Organellesundergo saltatory movement in the cell.

(b) Only themicrotubule cytoskeleton is involved in organellar movement.

(c) Motor proteinsinvolved in organellar movement use ATP hydrolysis for energy.

(d) Organelles areattached to the tail domain of motor proteins.

8. ___ Which of thefollowing statements is correct?

Kinesins and dyneins____________________.

(a) have tails thatbind to the filaments

(b) move along bothmicrotubules and actin filaments

(c) often move inopposite directions to each other

(d) derive their energyfrom GTP hydrolysis

9. ___ Cell movementinvolves the coordination of many events in the cell. Which of thefollowing phenomena are not required for cell motility?

(a) Myosin-mediatedcontraction at the rear of the moving cell.

(b) Integrinassociation with the extracellular environment.

(c) Nucleation ofnew actin filaments.

(d) Release ofCa2+ from the sarcoplasmic reticulum.

10. ___Which of the followingstructures shorten during muscle contraction?

(a) myosinfilaments

(b) flagella

(c) sarcomeres

(d) actin filaments

7. ___ Referring to Figure Q16-29,which of the following statements below is false?

(a) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to adecrease in the amount of unphosphorylated phosphorylasekinase.

(b) A constitutivelyactive mutant form of PKA in skeletal muscle cells would notincrease the affinity of adrenaline for the adrenergicreceptor.

(c) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to anexcess in the amount of glucose available.

(d) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to anexcess in the amount of glycogen available.

8. ___ Match the targetof the G protein with the appropriate signaling outcome.

adenylyl cyclase________ A. cleavageof inositol phospholipids

ion channels_________ B.increase in cAMP levels

phospholipase C_________ C. changes in membranepotential


Hello everyone, i'm working on thesepractices multiple choices for my finals. If you know any of theseanswer, please help. i appreciate your time and your help. Thankyou!!!

1. ___ Which of thefollowing statements about the cytoskeleton is false?

(a) The cytoskeletonis made up of three types of protein filament.

(b) The bacterialcytoskeleton is important for cell division and DNAsegregation.

(c) Protein monomersthat are held together with covalent bonds form cytoskeletalfilaments.

(d) The cytoskeleton of acell can change in response to the environment.

2. ___ Which of thestatements below about intermediate filaments is false?

(a) They can stayintact in cells treated with concentrated salt solutions.

(b) They can befound in the cytoplasm and the nucleus.

(c) They can beanchored to the plasma membrane at cell-cell junction.

(d) Each filament is about10 ?m in diameter.

3. ___ Keratins,neurofilaments, and vimentins are all categories of intermediatefilaments. Which of the following properties below is nottrue of these types of intermediate filaments?

(a) They strengthencells against mechanical stress.

(b) Dimers associateby noncovalent bonding to form a tetramer.

(c) They are foundin the cytoplasm.

(d) Phosphorylation causesdisassembly during every mitotic cycle.

4. ___ Which of thefollowing statements about microtubules is true?

(a) Motor proteinsmove in a directional fashion along microtubules by using theinherent structural polarity of a protofilament.

(b) The centromerenucleates the microtubules of the mitotic spindle.

(c) Becausemicrotubules are subject to dynamic instability, they are used onlyfor transient structures in a cell.

(d) ATP hydrolysis by atubulin heterodimer is important for controlling the growth of amicrotubule.

5. ___ Thehydrolysis of GTP to GDP carried out by tubulin molecules________________.

(a) provides theenergy needed for tubulin to polymerize

(b) occurs becausethe pool of free GDP has run out

(c) tips the balancein favor of microtubule assembly

(d) allows the behavior ofmicrotubules called dynamic instability

6. ___ The microtubulesin a cell form a structural framework that can have all thefollowing functions except which of the following?

(a) holding internalorganelles such as the Golgi apparatus in particular positions inthe cell

(b) creating longthin cytoplasmic extensions that protrude from one side of thecell

(c) strengtheningthe plasma membrane

(d) moving materials fromone place to another inside a cell

7. ___ Which of thefollowing statements about organellar movement in the cell isfalse?

(a) Organellesundergo saltatory movement in the cell.

(b) Only themicrotubule cytoskeleton is involved in organellar movement.

(c) Motor proteinsinvolved in organellar movement use ATP hydrolysis for energy.

(d) Organelles areattached to the tail domain of motor proteins.

8. ___ Which of thefollowing statements is correct?

Kinesins and dyneins____________________.

(a) have tails thatbind to the filaments

(b) move along bothmicrotubules and actin filaments

(c) often move inopposite directions to each other

(d) derive their energyfrom GTP hydrolysis

9. ___ Cell movementinvolves the coordination of many events in the cell. Which of thefollowing phenomena are not required for cell motility?

(a) Myosin-mediatedcontraction at the rear of the moving cell.

(b) Integrinassociation with the extracellular environment.

(c) Nucleation ofnew actin filaments.

(d) Release ofCa2+ from the sarcoplasmic reticulum.

10. ___Which of the following structures shortenduring muscle contraction?

(a) myosinfilaments

(b) flagella

(c) sarcomeres


(d) actin filaments

7. ___ Referring to Figure Q16-29,which of the following statements below is false?

(a) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to adecrease in the amount of unphosphorylated phosphorylasekinase.

(b) A constitutivelyactive mutant form of PKA in skeletal muscle cells would notincrease the affinity of adrenaline for the adrenergicreceptor.

(c) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to anexcess in the amount of glucose available.

(d) A constitutivelyactive mutant form of PKA in skeletal muscle cells would lead to anexcess in the amount of glycogen available.

8. ___ Match the targetof the G protein with the appropriate signaling outcome.

adenylyl cyclase________ A. cleavageof inositol phospholipids

ion channels_________ B.increase in cAMP levels


phospholipase C_________ C. changes in membranepotential


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 cell’s 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