The molecular cell cycle Flashcards
The cell cycle – why yeast?
Easy for us to see under a microscope + loads of visible replications
How can we identify and see each stage?
Process by which single eukaryote gives rise to two identical daughter cells.Most cells have a finite capacity for division and can be senescent at anytime- scenesent -process by which the cells irreversibly stop dividing and enter a state of permenant growth arrest without undergoing cell death.Senescent cells sit within the tissue and can change the plasticity of the tissue, the longer they sit around can be promoting a cancer
What gene group is responsible?
E2F is a group of genes that encodes a family of transcription factors(TF) in higher eukaryotes
What are the events of the cell cycle?
Interphase,G1,S,G2 and Mitotic Phase.
What happens at g1?
Part of interphase – during the first gap – the cells grow physically larger, copies organelles and makes the molecular building blocks it will need in later steps, the availability of growth factors will control the animal cell cycle at a point in late g1 phase, called the restriction point; if growth factors are not available during g1, the cells enter a quiescent stage of the cell cycle called g0.
What happens at S?
also part of interphase, the cell synthesises complete copy of DNA in its nucleus- also duplicates a microtubule structure calles the centromere- the centromere help sepearte dna during the M phase.
What happens at G2
During the second gap phase, the cell grows more – makes proteins and organelles and begins to reorganise its content in preparation for mitosis . G2 ends as mitosis begins.
What happens at the mitotic phase?
The cell divides its copied DNA nd cytoplasm to make 2 new cells.Mphase involves 2 distinct division- related processes.
Mitosis and cytokinesis
In the prophase of mitosis, chromosomal Material condenses to form compact mitotic chromosomes.The cytoskeleton is disassembles and mitotic spindle is assembled.
In the prometaphase, the chromosmomal microtububles attach to kinetochores of chromosomes and are moved to spindle equator.
In metaphase- chromosomes are aligned along the metaphase plate and are attached to both poles by microtubules
In anaphase- the centromeres split and chromatids separate moving the chromosomes to opposite single poles.
In telophase, the chromosomes cluster at opposite poles.The nuclear membrane assembles around the cluster which daughter cells formed by cytokinesis.
What are the 4 nucleotides?
Adenine Guanine, Thymine, cytosine
What Is non mutagenic replication?
Non muatnigenic replication of every
nucleotide is essential once per cycle, only one copy should be made and no
muations!
Which nucleotides are pyrimidines?
Thymine and cytosine
Which nucleotides are purines?
Adenine and guanine
Why do we incorporate radiolabelled nucleotides?
3h-thymidine) are in cooperated
into cells at DNA replication. Using X ray or antibody staining, cells in S- phase may be identified. Flow cytometric detection of cells stained with DNA dyes allows the discrimination of cells with variable DNA content. Cells in G1 phase – peak 1 contain half the DNA of cells after DNA replication in G2 and M(peak 2), cells in the process of replication (S- Phase) contain an intermediate quantity.
What is the role of Cyclins and what do CDKs stand for?
In order to drive the cell cycle forward. Cyclin dependant kinases. A cycline must activate or inactivate target proteins inside the cell.- cyclins drive the event of a cell cycle by partnering with a family of enzymes called cdks. A lone cdk is inactive but when a cyclin is involved it becomes activated -making it a functional enzyme and allowing it to modify target proteins.
What is the cdk required for a cell cycle to take place and what is the name of an important example of one of them?
Cdk 1 is required to drive through the cell stages.Cyclin B1 and A2 are essential for a normal cell cycle