Ch.10 Vocab

Molecular biology

studies macromolecules and the macromolecular mechanisms found in living things

Nucleotide

are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate

Polynucleotide

a polymer composed of several nucleotides linked together

Sugar-phosphate backbone

composed of alternating sugar and phosphate groups, and defines directionality of the molecule

DNA

Thymine

one of the bases pairs with Adenine

Cytosine

one of the bases pairs with Guanine

Adenine

one of the bases pairs with Thymine

Guanine

one of the bases pairs with Cytosine

Uracil

one of the four nucleotide bases in RNA in DNA is called Thymine

Double helix

a term used to describe the physical structure of DNA

Semiconservative model

after one round of replication, every new DNA double helix would be a hybrid that consisted of one strand of old DNA bound to one strand of newly synthesized DNA

DNA polymerase

a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates

DNA ligase

a type of enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond

purine

a type of nitrogen bases for adenine and guanine

pyrimidine

One of two families of nitrogenous bases found in nucleotides

Helicase

“unzips” the DNA strand in replication

Origin of replication

where the “bubble” is formed

Okazaki fragment

small sections of DNA that are formed during discontinuous synthesis of the lagging strand during DNA replication

Leading strand

the strand of nascent DNA which is synthesized in the same direction as the growing replication fork. The synthesis of leading strand is continuous.

Lagging strand

strand that requires a slight delay before undergoing replication

3’ end

that end of the molecule which terminates in a 3' phosphate group

5’ end

A DNA strand with the fifth carbon within the sugar ring at its end