Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
what are the 3 reasons that cells grow and divide?
|
to generate tissues eg during development
to make those tissues grow to make up for "wear and tear" on those tissues |
|
|
what are the 2 stages of cell growth and divsion?
|
1. hyperplasia - cell division
2. cell growth |
|
|
What are the 3 stages of hyperplasia?
|
1. exact duplication of the cellular DNA by semi-conservative replication
2. segregation of the replicated DNA into 2 identical daughter cells 3. equal division of cytoplasm and organelles between the 2 daughter cells |
|
|
what are the concurrent cycles that are inter-dependent in the cell cycle?
|
1. chromosome cycle - DNA replication and segregation - mitosis
2. cytoplasmic cycle - organelle replication and physical separation of the daughter cells (cytokinesis) 3. centrosome cycle - replication of the mitotic spindle |
|
|
what is the resting phase of the cell cycle called? What 3 stages does it consist of?
|
interphase.
S phase G1 G2 |
|
|
what activates the kinase activity of CDKs?
|
the binding of cyclins
|
|
|
what is mitosis triggered by?
|
formation of M-CDK and activation of this CDK through phosphorylation by CDK-activating kinase
|
|
|
what is DNA synthesis triggered by?
|
formation of S-CDK and activation of this CDK
|
|
|
how do the cell cycle checkpoint proteins work?
|
through negative intracellular signals.
|
|
|
what are the 2 external influences on cell growth and division?
|
1. mitogens
2. growth factors |
|
|
what do mitogens do?
|
trigger cell division. They overcome the intracellular mechanisms that block the cycle. They interact with cell-surface receptors and trigger a signalling cascade resulting in increased transcription of genes for G1-CDK and G1/S CDK
|
|
|
what do growth factors do?
|
trigger cell division AND cell differentiation. Extracellular molecules that bind to cell surface receptors. Activate pathways inaddition to those determined by CDK/cyclin
|
|
|
what does M-CDK do?
|
leads to phosphorylation of nuclear lamins and disintegration of nuclear membrane - essential for mitosis to proceed
|
|
|
what is the mitotic spindle made of?
|
tubulin-containing microtubules and kinesin and cytoplasmic dynein motors
|
|
|
what is the contractile ring made of?
|
actin-containing microfilaments and associated motors of the myosin family
|
