Molecular Biology Lecture Notes - DNA Replication and Gene Expression

These flashcards cover critical concepts related to DNA replication, gene expression, and molecular biology based on the lecture notes.

Bacteriophage

A virus that infects bacteria, notable from the Hershey-Chase experiment.

Hershey-Chase experiment

An experiment that demonstrated that DNA is the genetic material using bacteriophages.

Semiconservative replication

The method of DNA replication where each new DNA molecule contains one original strand and one new strand.

Mieseson-Stahl experiment

An experiment that confirmed the semiconservative model of DNA replication.

DNA polymerase III

The enzyme responsible for the bulk synthesis of DNA during replication.

DNA ligase

An enzyme that seals nicks in the DNA backbone after replication and repair processes.

Leading strand

The strand of DNA that is synthesized continuously in the same direction as the replication fork.

Lagging strand

The strand of DNA that is synthesized discontinuously in the opposite direction of the replication fork.

Polymerase Chain Reaction (PCR)

A method used to amplify a specific DNA segment, producing millions of copies.

Proofreading

The ability of DNA polymerases to check and correct errors during DNA replication.

Mismatch repair

The process by which the cell identifies and corrects mismatched bases in DNA.

Pyrimidine dimers

Covalent linkages between adjacent pyrimidines (like thymine) caused by UV radiation.

Zero derma pigmentosa

A genetic disorder that increases sensitivity to UV light due to impaired DNA repair.

Central dogma of molecular biology

The framework describing the flow of genetic information from DNA to RNA to protein.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing proteins from RNA sequences.

One gene, one enzyme hypothesis

A hypothesis stating that genes encode the enzymes that catalyze biochemical reactions.

mRNA

Messenger RNA, the type of RNA that conveys genetic information from DNA to the ribosome.

Start codon

The codon that signals the start of translation, typically AUG.

Stop codon

A codon that signals the termination of protein synthesis.

Redundancy in genetic code

The property of the genetic code in which multiple codons can encode the same amino acid.

Evolutionary advantage

A characteristic or trait that increases the likelihood of survival and reproduction.

Gene expression

The process by which the information from a gene is used to synthesize a functional gene product like a protein.

Codon

A sequence of three nucleotides in mRNA that corresponds to a specific amino acid.