1
complementary base pairs
A and T, G and C
what is mitosis?
division of the nucleus in somatic cells
hydrogen bonds
ATP + H2O ---> creates what?
ADP + Pi + energy
23
What happens in binary fission?
DNA (circular chromosome) replicates
What is deoxyribonucleic acid?
RNA full name
Ribonucleic acid
What is it necessary to have cell cycle checkpoints?
to check for mutations
What does a kinase do?
Phosphorylates another molecule
double-stranded DNA molecules in the form of chromosomes
nucleotide structure
Phosphate, pentose sugar (ribose or deoxyribose), Nitrogenous base (A,G,C,T,U)
are somatic cells diploids or haploids?
diploids
What is cytokinesis?
• Physical separation of the cytoplasm into two daughter cells.
• Begins during anaphase or telophase
What do tumor suppressor genes do?
• Confirm accuracy of DNA replication
• Stop mitosis in damaged cells
• Trigger “apoptosis” of damaged cells
What are tumor suppressor genes?
Segments of DNA that code for negative regulator proteins
approximately 2 million of DNA
What are oncogenes?
genes that cause a cell to become cancerous
What do CDKS do?
What happens in prophase and prometaphase?
Chromosomes condense
• Nuclear membrane breaks down
• Nucleolus disappears
• Centrosomes migrate to poles
• Spindle microtubules form
what happens in telophase?
• Chromosomes decondense
• Nuclear envelopes reform
• Mitotic spindles degrade
What are cyclin and cyclin-dependent kinase(CDK)?
• Positive regulators
• Cdk only active when bound to cyclins
• Also requires phosphorylation at activating sites
what happens in metaphase?
• Chromosomes line up along metaphase plate
• Sister chromatids attach to microtubules from opposite poles
what happens in anaphase?
• Cohesin proteins degenerate and chromatids separate
• Sister chromatids move toward the centrosomes at opposite poles
• The cell elongates