8 - DNA Structure and Function

Histones

Type of protein that DNA molecules wrap around

Nucleosome

DNA-wrapped-around-histone spool

Sister chromatid

Two identical halves of a duplicated eukaryotic chromosome

The two legs of the iconic chromosome look

Centromere

The middle belt that holds

Chromosome number

total number of chromosomes in a cell of a given species

Diploid

Having two of each type of chromosome characteristic of the species (2n)

karyotype

image of an individual cell’s DNA, for Down Syndome, Turner Syndrome etc

Autosome

All 22 of 23 in human chromosomes that are not sex chromosomes

Initiator proteins

Allows other enzymes to bind to the DNA, starts the replication process

Topoisomerase

Untwists the double helix

Helicase

Unzips your jeans

aka breaks hydrogen bonds between bases

Primer

Made my the enzyme primase, attachment point for replication

Hybridization

Spontaneous establishment of base pairing between two nucleic acid strands, causes primer to hydrogen bond with DNA

DNA polymerase

Enzyme that carries out DNA replication and works off the primer

DNA ligase

Enzyme that seals any gaps in the sugar-phophate backbone of the new strands of DNA

Semiconservative replication

Two strands of DNA are formed from one parent strand, each keeping one side of the parent strand, so it’s called this