DNA Assesment Vocab

Pyrimidines

single ring bases

Purines

double ring bases

hydrogen bond

the attractive force between the 2 bases.

major groove

occurs where the backbones are far apart

minor groove

occurs where they are close together.

parental strand

original strand of DNA

Helicase

enzyme that breaks hydrogen bonds and uncoils DNA

single-stranded binding proteins (SSBP)

holds the DNA open

Replication bubble

makes replication go faster and has 2 helicases moving in opposite directions

Primase

adds an RNA primer to the template DNA strand so that the next enzyme can stick and do its job.

DNA polymerase 3

The daughter DNA strands are built by adding complementary nucleotides to the template strands

Lagging strand

is made discontinuously , in short segments. It takes longer- lags behind

Leading strand

made in 1 continuous piece

(The arrow goes in the same direction as helicase)

Okazaki Fragments

The pieces of new DNA on the lagging strand

are called:

DNA polymerase 1

exchanges the RNA bases for DNA bases

Ligase

Okazaki Fragments are bonded together to with covalent (phosphodiester) bonds by the enzyme

DNA polymerase II

proofreads & corrects mutations due to replication

The “Central Dogma”

Flow of genetic information in a cell

Post-transcriptional processing

processing RNA before it leaves nucleus

Polypeptide chain

chain of amino acids

large subunit

top half of a ribosome

Small subunit

bottom half of a ribosome

Codon

3 letters of mRNA are called a:

Splicing

process of removing the noncoding regions of mRNA is known as

exons

region that tells us how to make amino acids

expressed

introns

non coding sections -do NOT make necessary amino acids

In-between the genes

Alternative Splicing

makes it possible to get multiple different proteins produced from a single gene in our DNA

mutagens

something that causes mutations

germline mutations

mutations you are born with

somatic mutations

mutations you get during your lifetime

point mutations

When a base (pair) is replaced / swapped out with a different one.

silent mutations

point mutations that DO NOT result in a change to the amino acid sequence of a protein.

substitution mutation

point mutations where you get a different amino acid.

nonsense mutation

is a point mutation that results in a premature stop codon.

Frameshift mutation

caused by an insertion or deletion of a number of nucleotides that is not evenly divisible by 3. (not removing / adding 1 codon)