Somatic cell cycle Flashcards
RNA Primase
Enzyme that makes Rna primers
DNA polymerase
enzyme that makes new DNA strands
Leading Strand
new DNA strand, made in 1 piece
Lagging Strand
new DNA strand, made in fragments
chromosome
entire double helix DNA
Karyotype
number of chromosomes in a cell
Chromatid
identical copy of a chromosome
What is the cell cycle
G1, S, G2, M, C
G1 Phase
DNA Packaging
Synthesis phase
replication of DNA
G2
replication of organelles
Mitosis
separation of chromatids
Cytokinesis
separation of cells
how many homologous pairs are in a human
23
whats the human karyotype
46
what is a replisome
all the enzymes involved in DNA replication
leading strand synthesis
continuous synthesis
- whole strand extended by
- 1 rna primer removed and replaced by DNA
- DNA ligase seals backbone of new strand
lagging strand synthesis
discontinuous synthesis
- many okazaki fragments extended by DNA polymerase
- Manr RNA primers removed and replaced by DNA
DNA Repair
errors made during S phase
fixed by specific or nonspecific repair mechanisms
Photorepair
Damage from UV light
-photolyase absorbs rest of light and breaks thymine dimer
excision repair
- a non specific repair mechanism
- damaged region is removed
- replaced by DNA synthesis
end of S phase
kayotype is doubled
- 2 identical dna fibers
- held together by proteins at the centromere
after S phase
replicates centrioles
-condensing chromosomes
once visible- M phase
The five phases of mitosis
- prophase
- prometaphase
- metaphase
- anaphase
- telophase
prophase
chromosomes become slightly visible
- centrioles move to opposite poles forming spindle apparatus
- nuclear membrane starts to break down
prometaphase
centrioles connect to kinetochore
-chromosomes begin to move to the center of the cell
metaphase
chromosomes align along the center plate
anaphase
chromosomes split at centromere
-sister chromatids pulled to opposite poles
telophase
nuclear membrane reforms
- chromosomes begin to uncoil
- chromatids are on opposite sides
cytokinesis
cleave furrow appears
-cell begins to split in half
g1/s checkpoint
cell decides to divide
g2/m checkpoint
asses success of DNA replication
checks to see if there is enough for 2 cells
late metaphase checkpoint
checks to ensure all chromosomes are attached to their spindle
-did everything go to the right cell?
Proto-onco Genes
controls normal cell
protein that can be stuck in βonβ mode for uncontrolled cell division
tumor-supressor genes
defense against proto-onco
ensures it makes the correct amount of cells
apoptosis
programmed cell death
necrosis
accidental cell death