1.5 protein control of cell division Flashcards
what is the cytoskeleton?
a network of proteins extending throughout the cytoplasm, anchored to proteins in the PM
what is the function of the cytoskeleton?
- provide mechanical support so that the cell maintains its shape
- provide anchorage for many organelles
what is the cytoskeleton made of?
several types of protein, including microtubules
what are microtubules?
hollow cylinders made of a protein called tubulin
where are microtubules formed and radiated from?
a centrosome or MTOC (microtubule organising centre)
what is the role of microtubules?
- govern the location and movement of the membrane-bound organelles and other cell components
- form the spindle fibres that are active during cell division
how are spindle fibres formed then broken down?
by polymerisation and then depolymerisation of tubulin
what does cell division allow?
organisms to grow and develop, by regulating the growth and replacement of genetically identical cells
name the two parts into which the cell cycle can be divided
interphase
the mitotic phase
describe interphase
an active period of growth
name the three sub-phases that interphase can be divided into
G1, G2, S
describe G1
a growth period where proteins and organelles are synthesised
what happens during S phase
the cell continues to grow and DNA replication takes place
describe G2
another growth period
what happens after G2
the cell enters the mitotic phase
what happens during the mitotic phase?
mitosis and cytokinesis
what is mitosis?
when the nucleus and contents divide
what is cytokinesis?
the separation of the cytoplasm into daughter cells
what could an uncontrolled reduction in the rate of the cell cycle result in?
degenerative diseases
what could an uncontrolled increase in the rate of the cell cycle result in?
tumour formation