Bio Unit 3: DNA

DNA

DNA

genetic material that organisms inherit from their parents

histone

protein that helps condense DNA

nucleotide

subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogen base

phosphate

chemical compound that contains phosphorus; makes up the DNA backbone

nitrogen bases

adenine, thymine, guanine, cytosine, or uracil

adenine

nitrogen base that pairs with thymine in DNA and uracil in RNA

thymine

nitrogen base that pairs with adenine (found in DNA)

guanine (G)

nitrogen base that pairs with cytosine

cytosine (C)

nitrogen base that pairs with guanine

double helix

the appearance/physical structure of double-stranded DNA

hydrogen bonds

the bond that connects two complementary nitrogen bases

anti-parallel

the two strands of DNA run in opposite directions of 3’ to 5’ or 5’ to 3’

replication bubble

an open region of DNA where DNA replication occurs; created by the separation of two strands from the helicase enzyme

leading strand

DNA strand created by the DNA polymerase that has a continuous path

lagging strand

DNA strand created by the DNA polymerase that is interrupted and built in small sections (Okazaki Fragments)

helicase

DNA replication enzyme that unwinds the DNA by breaking hydrogen bonds; creates a replication bubble and fork

primase

DNA replication enzyme that adds small sequences of primer so the DNA polymerase knows where to go

ligase

DNA replication enzyme that glues Okazaki Fragments together and reconnects the hydrogen bonds between nitrogen bases

DNA polymerase

DNA replication enzyme that creates complementary bases to the original DNA strand; forms the leading and lagging strands

RNA

single stranded nucleic acid that contains the sugar ribose

mRNA (messenger RNA)

type of RNA that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cells

tRNA (transfer RNA)

type of RNA that carries each amino acid to a ribosome during protein synthesis

RNA polymerase

enzyme that links together the growing chains of RNA nucleotides during transcription using a DNA strand as a template

transcription

synthesis of an RNA molecule from a DNA molecule

intron

sequence of DNA that is not involved in coding for a protein

exon

expressed sequence of DNA; codes for a protein

protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

amino acid

compound with an amino group on one end and a carbozyl group on the other

ribosome

cell organelle of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis

translation

process by which the sequence of bases of mRNA is converted into the sequence of amino acids for a protein

codon

group of three nucleotide bases in mRNA that specify particular amino acid to be incorporated into a protein

anticodon

group of three bases on a tRNA molecule that are complementary to the three bases of a codon of mRNA

mutation

change in the genetic material of a cell

point mutation

gene mutation in which a single base pair in DNA has been changed

chromosomal mutation

frameshift mutation

mutation that shifts the “reading frame” of the genetic message by intersecting or deleting a nucleotide

gene

sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from the parent to offspring

central dogma