Term
| What is the function of cytoskeleton? |
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Definition
| Provides mechanical support and shape to cells |
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Term
| What does the cytoskeleton consist of ? |
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Definition
| protein structures including microtubules |
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Term
|
Definition
| hollow cylinders made of the protein tubulin |
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Term
| What does MTOC stand for? |
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Definition
| Microtubule organising centre |
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Term
| What is another name for the MTOC? |
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Definition
|
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Term
| Give two functions of microtubules. |
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Definition
| Guide the movement of organelles within the cell and the movement of chromosomes in cell division. |
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Term
| What does the formation and breakdown of microtubules involve? |
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Definition
| polymerisation and depolymerisation of tubulin |
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Term
| What are the two main phases of the cell cycle? |
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Definition
| interphase and mitotic phase |
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Term
| Which 2 events happen in Interphase? |
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Definition
|
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Term
| What are the three steps of Interphase? |
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Definition
|
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Term
| What are the two parts of the mitotic phase? |
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Definition
|
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Term
| State the four stages of mitosis in the correct order. |
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Definition
| Prophase/ Metaphase/ Anaphase/ Telophase |
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Term
| What happens in cytokinesis? |
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Definition
| Cytoplasm is separated into two daughter cells |
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Term
| What happens in prophase? |
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Definition
| DNA condenses into chromosomes each consisting of two sister chromatids. Nuclear membrane breaks down; spindle microtubules extend from the MTOC by polymerisation and attach to chromosomes via their kinetochores in the centromere region. |
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Term
| What happens in metaphase? |
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Definition
| chromosomes are aligned at the metaphase plate (equator of the spindle) |
|
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Term
| What happnes in anaphase? |
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Definition
| as spindle microtubules shorten by depolymerisation, sister chromatids are separated, and the chromosomes are pulled to opposite poles. |
|
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Term
| What happens in telophase? |
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Definition
| the chromosomes decondense and nuclear membranes are formed around them |
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Term
|
Definition
| Area of a chromosome to which spindle fibres attach during mitosis |
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Term
| What are the mechanisms in a cell that halt progression to next phase until certain requirements are met? |
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Definition
|
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Term
| Name the proteins that accumulate during cell growth and are involved in regulating cell cycle. |
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Definition
|
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Term
|
Definition
|
|
Term
| What do CDKs do when activated by cylcins? |
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Definition
| They phosphorylate proteins that regulate progression through the cell cycle. If sufficient phosphorylation is reached, progression occurs. |
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Term
| What is the purpose of G1 checkpoint in Mitosis? |
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Definition
| Check cell size is sufficiently large before mitosis continues. |
|
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Term
| What is the function of retinoblastoma protein (Rb)? |
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Definition
| Rb is a tumour suppressor, inhibiting the transcription of genes that code for proteins needed to replicate DNA |
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Term
| What effect does phosphorylation by G1 CDKs have on retinoblastoma? |
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Definition
| the retinoblastoma is inhibited and so transcription of genes for proteins needed for DNA replication can proceed. |
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Term
| What happens at the G2 checkpoint? |
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Definition
| success of DNA replication / DNA damage is assessed |
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Term
| What happens if DNA damage is detected at the G2 checkpoint? |
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Definition
|
|
Term
| What effects can p53 have on the cell? |
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Definition
| DNA repair, arrest the cell cycle or cause cell death |
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|
Term
| What is the purpose of the metaphase checkpoint? |
|
Definition
| to check chromosomes are aligned correctly on the metaphase plate and attached to the spindle microtubules. |
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Term
| What can an uncontrolled reduction in cell cycle rate result in? |
|
Definition
|
|
Term
| What can an uncontrolled increase in cell cycle rate result in? |
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Definition
|
|
Term
| Name two types of degenerative disease. |
|
Definition
| Alzheimer's and Parkinson's Diseases |
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|
Term
| What is a proto-oncogene? |
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Definition
| A normal gene involved in cell growth or division capable of mutating into a cancer-causing gene. |
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Term
|
Definition
|
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Term
|
Definition
| Cell death signals (internal eg p53 ) or external (binding of signal molecules from lymphocytes to surface receptors in the plasma membrane.) |
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Term
| Why is apoptosis useful in metamorphosis? |
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Definition
| Removes cells no longer required in development and allows the transformation of the organism. |
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Term
|
Definition
| Protease enzyme, that cause the destruction of the cell |
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