Biology I Test 4

DNA

deoxyribonucleic acid

Nucleotide of DNA

basic structure of DNA; made up of deoxyribose sugar, nitrogenous base, and phosphate

Adeline, Cytosine, Guanine, Thymine

The four nitrogenous bases that make up the building blocks of DNA

RNA

ribonucleic acid

Nucleotide of RNA

ribose sugar, nitrogenous base, phosphate

Uracil

substitutes for thymine in RNA

Helicase

unwinds DNA

Ligase

fills in the gaps in the lagging strand during DNA replication

Topoisomerase

corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

Primase

An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.

hydrogen bonds

weak attraction between a hydrogen atom and another atom

Antiparallel DNA strands

one strand goes 3' to 5' the other goes 5' to 3

leading strand

synthesized continuously

lagging strand

The strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up.

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication

5' and 3' carbons

Indicate directionality of DNA strands.

mammary cells

milk-secreting cuboidal cells

Agarose gel

A polysaccharide obtained from seaweed that is used as the supporting medium in gel electrophoresis.

DNA fragments

Pieces of DNA strand cut by restriction enzymes

Forensics

scientific study of crime scene evidence

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

gene

A segment of DNA on a chromosome that codes for a specific trait

RFLP (restriction fragment length polymorphism)

a variation in the length of restriction fragments produced by a given restriction enzyme in a sample of DNA. Such variation is used in forensic investigations and to map hereditary disease.

introns

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

exons

expressed sequence of DNA; codes for a protein

why do white blood cells have a nucleus but red don't?

Red blood cells already made all the proteins that the will ever need

PCR (polymerase chain reaction)

is used to copy and amplify minute quantities of DNA