cyclins. The cyclins are going to complex cyclin dependent kinase (CDK). Kinases phosphoralyte things. So CDK gets turned on by the presence of cyclin so that the target proteins get phosphorylated and change the DNA expression based on this route to cause mitosis to occur. The cyclins degrade and target solutions get turned off when they are no longer needed to regulate cell cycle. Whenever the cell speeds up its cell cycle so it can go from G1 to s to G2 we see a peak in the abundance of cyclins inside the cell. We can see cyclin concentrations over time as we progress through the cell cycle. G1 S cyclin has the job of pushing us from G1 and prepare the cell for DNA synthesis
S cyclin has the job to push the cell from G1 all the way through G2, and then M cyclin takes over and pushes into mitosisCheckpoints along the way so that the cell cycle doesn’t perceive when there is damage. oThe first checkpoint is the DNA damage checkpoint. Even if there is G1S cyclin present there is a protein inside the nucleus called P53 and it is always present, however if there is a lot of damage like broken DNA, the DNA triggors a different kinase to phosphorylate P53 and turn it on. When it comes on it will block the cell from entering S phase. Even if the CDK is activated, P53 will block that transition step and will trigger the repair of DNA to occur in G1. If you have a mutation to P53 that stopped it from working, it would not be able to block the progression of the cell into s phase and it allows DNA to be replicated and any mutations that occur to be passed on to subsequent cells. If you have a P53 mutation its not the end of the world because there are subsequent checkpoints at the end of the s phase and in G1Also for the cell to replicate uncontrollably In order for a cell to become cancerous you need multiple mutations accumulated in the control systems like P53 and in the cyclins in order for cancer cells to be able to spread or form.Viruses are capable of transmitting oncogenes (a gene that can lead to cancer)Protoncogene are human cells that have a high likely hood of becoming oncogene mutation There are many genes that act as tumor suppressors 11/2/16DNA Replication chapter 12When we reproduce we want more diversity which is part of crossing over and shuffeling all of the alleles, after reproducing the expression of the genes in the offspringWe want DNA replication to be a sound process with no errors and correctly transmits the DNA to our offspring because DNA, alleles are our units of heredity information that gets passed on to our offspring. So it needs to be a high fidelity system. DNA structure is a double helix made of base pairs ATGC, deoxyribonucleic acid G binds to c, A binds to T. ALL GOLD IS PUREThe sequences of nucleudes code for genes, proteins The molecule of DNA is a double helix that unwinds, then each single stranded path of the double stranded molecule acts as the template for the synthesis of a new strand Called semi conservative replication.