DNA Replication Flashcards
DNA replication:
the biological process of producing two identical replicas of DNA from one original DNA molecule
DNA replication occurs ____
in the nucleus of the cell
Helicases:
enzymes that bind and remodel nucleic acid, or nucleic acid protein complexes
How do helicases work?
by unwinding the double helix, and separating the two strands by breaking the hydrogen bonds between the complementary base pairs
DNA polymerase:
link nucleotides together to form a new strand using the pre-existing strand as a template (polymerisation is a condensation reaction)
Process of DNA helicase unwinding DNA strands (out of 4):
- unwinds DNA helix
- separates the two polynucleotide strands
- ATP needed by helicase to move along DNA molecule and break H-bonds
- Two separated strands become parent/template strands for the replication process
Process of DNA polymerase creating complementary strands (out of 3):
- DNA polymerase always moves in a 5’ to 3’ direction
- DNA polymerase catalyses the covalent bonds between sugar and phosphate groups
- DNA polymerase ‘proof reads’ the complementary base pairing
DNA replications moves in a 5’ to __ direction
3’
Gene expression:
genes are heritable factors that serve to influence specific characteristics. a gene occupies a specific position on one type of chromosome (the locus of the gene)
Alleles:
the various specific forms of a gene
Genome:
all the DNA in an organism, including its genes, which forms the entire base sequence of each of its DNA molecules
Genes code to make:
polypeptides
DNA is stored in the ____ but the polypeptides are produced in the ____ by ____
nucleus, cytoplasm, ribosomes
mRNA:
messenger RNA - the instructions sent from the nucleus to the ribosomes on how to construct the polypeptide - this genetic code is the sequence of bases on the mRNA
