1.5 - Protein control of cell division

studied byStudied by 5 people
5.0(2)
get a hint
hint

Cytoskeleton

1 / 31

Tags and Description

Biology

32 Terms

1

Cytoskeleton

Network of different types of proteins that extends throughout the cytoplasm. The cytoskeleton gives mechanical support and shape to cells.​

New cards
2

Microtubules

Make up the cytoskeleton. They are composed of hollow straight rods made of globular proteins called tubulins.

New cards
3

Role of microtubules

Govern the location and movement of membrane-bound organelles and other cell components​.

New cards
4

Centrosome (microtubule organising centre/MTOC).​

Where microtubules radiate from

New cards
5

Role of microtubules in cell division

Microtubules form spindle fibres which are active during cell division. Cell division requires the remodelling of a cell's cytoskeleton

New cards
6

Polymerisation and depolymerisation

Formation and breakdown of microtubules involves the build up and break down of tubulin

New cards
7

Two main phases of the cell cycle

interphase and mitotic phase (M phase)

New cards
8

The phase in which a cell spends the majority of its time

Interphase

New cards
9

Three parts of interphase

G1, S, G2

New cards
10

The two processes that occur during the M phase

Mitosis and Cytokinesis

New cards
11

The stages of mitosis

Prophase, metaphase, anaphase and telophase

New cards
12

Cytokinesis

The division of the cytoplasm

New cards
13

Prophase

Replicated chromosomes condense (become shorter and fatter) and appear as pairs of identical sister chromatids. ​ Centrosomes move apart and microtubules radiate out from them to form spindle fibres.​ Nuclear membrane is broken down.

New cards
14

Metaphase

Multiple spindle fibres become attached to each sister chromatid. ​ Replicated chromosomes are aligned at the equator of the spindle fibres that are attached to them. This position is called the metaphase plate.

New cards
15

Anaphase

Proteins holding the sister chromatids together are degraded.​ Sister chromatids separate.​ Spindle fibres attached to each of the daughter chromosomes shorten to pull them to opposite poles of the cell.

New cards
16

Telophase

Chromosomes arrive at each pole of the cell and decondense (unravel). ​ A new nuclear membrane forms around each group of chromosomes, forming daughter nuclei.

New cards
17

Checkpoints

Critical control points where stop and go ahead signals regulate the cycle.​

New cards
18

Cyclin

Proteins that accumulate as the cell size increases during G1.​

New cards
19

Cyclin-dependent kinases (Cdks)

Regulatory proteins that are activated by cyclin. Active Cdks cause the phosphorylation of proteins that stimulate the cell cycle.

New cards
20

G1 Checkpoint

Progression occurs at this checkpoint if a sufficient threshold of phosphorylation is reached.​ If an insufficient threshold is reached then the cell is held at the checkpoint.

New cards
21

Retinoblastoma

A transcription factor phosphorylated by the G1 Cdks. This allows DNA replication in the S phase.

New cards
22

G2 checkpoint

At this checkpoint, the success of DNA replication and any damage to DNA is assessed​.

New cards
23

DNA damage

This triggers the activation of several proteins, include p53​ This can

  • Stimulate DNA repair​

  • Arrest the cell cycle​

  • Cause cell death

New cards
24

M phase Checkpoint

A checkpoint that controls progression from metaphase to anaphase. Spindle fibre assembly is checked for.

New cards
25

The role of the cell cycle

Regulates the growth and replacement of genetically identical cells throughout the life of the organism. ​

New cards
26

Uncontrolled reduction in the rate of the cell cycle

This leads to degenerative diseases such as Alzheimer's or Parkinson's.

New cards
27

Uncontrolled increase in the rate of the cell cycle

This leads to tumour formation

New cards
28

Proto-oncogene

A normal gene, usually involved in the control of cell growth or division, which can mutate to form a tumour-promoting oncogene

New cards
29

Apoptosis

This is triggered by cell death signals that activate inactive forms of DNAase and caspases (type of proteinase).​​ These enzymes then destroy the cell.

New cards
30

Cell death signals outwith the cell

Cell death signal binds to a surface receptor protein to activate a protein cascade, resulting in active caspases.​

New cards
31

Cell death signals within the cell

DNA damage results in the presence of p53 which can activate a caspase cascade​

New cards
32

Importance of apoptosis

​ It is essential during development of an organism to remove cells no longer required as development progresses or during metamorphosis​.

New cards

Explore top notes

note Note
studied byStudied by 2 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 32 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 10 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 2 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 19 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 5 people
Updated ... ago
5.0 Stars(2)
note Note
studied byStudied by 53 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 248 people
Updated ... ago
5.0 Stars(1)

Explore top flashcards

flashcards Flashcard33 terms
studied byStudied by 3 people
Updated ... ago
5.0 Stars(3)
flashcards Flashcard58 terms
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard95 terms
studied byStudied by 9 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard92 terms
studied byStudied by 13 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard43 terms
studied byStudied by 1 person
Updated ... ago
5.0 Stars(1)
flashcards Flashcard49 terms
studied byStudied by 30 people
Updated ... ago
5.0 Stars(3)
flashcards Flashcard23 terms
studied byStudied by 50 people
Updated ... ago
5.0 Stars(4)
flashcards Flashcard89 terms
studied byStudied by 15 people
Updated ... ago
5.0 Stars(2)