Chromosome & Organelle movement Flashcards
What molecular motors move along microtubules?
Dyneins & kinesins
How do molecular motors move along tracts
hydrolyse ATP
What governs directionality of movement
polarity of microtubule
Where is the plus end of microtubules located
cytoplasm
Describe Dynein
minus end directed motor
Dyneins undergo what type of transport
retrograde
What is retrograde transport
walk towards the centre of the cell
Describe Kinesin
plus end directed motor
Kinesins undergo what type of transport
anterograde
What is anterograde transport
walk out towards plus end
What type/s of transport do mitochondria undergo
anterograde and retrograde
Where are kinesins located
ONLY in cytoplasm
Where does the motor activity of kinesin reside
head domain at amino terminus
What is the function of multimeric kinesins
hold and pull microtubules together
Which kinesin is monomeric
kinesin 3
Describe kinesin 5
motor domains at both ends
What is the function of kinesin 5
binds and pulls microtubules
Which type of molecular motor is more diverse
Kinesins
What do dyneins require to interact with cargo?
adaptor proteins
Name some types of dyneins
cytoplasmic, cilliary
How do dyneins bind to their cargo
indirectly via proteins called the dynactin complex
What is the function of intermediate filaments in the cell cycle
control nuclear membrane architecture
What is the function of microtubules in the cell cycle
chromosome separation
What is the function of actin in the cell cycle
cytokinesis
When is the nuclear lamina disassembled
pro metaphase
What is the nuclear lamina made of
intermediate filament cage
What does phosphorylation of the nuclear lamina cause
disassembly & association with ER vesicles
What do kinetochore microtubules bind to
chromosome directly
What generates spindle poles
division of the centrosome
What is the function of astral microtubules
anchor spindle poles to opposite ends of cell
What is the function of polar microtubules
cross from one side of the spindle to another
What is the function of kinetochore microtubules
pull chromosomes to poles
How do kinetochore microtubules pull chromosomes
exert force on chromosome
What do kinetochore microtubules aid
chromosome alignment on metaphase plate
Describe the kinetochore microtubule movement in anaphase A
shorten
Describe the microtubules movement in anaphase B
lengthen and sliding of POLAR microtubules
Describe cytokinesis
separation of daughter cells
How are cells separated in cytokinesis
actin/myosin interaction causes pinch off in middle of cell
