DNA Replication, Transcription, and Translation

Comprehensive vocabulary flashcards covering DNA structure, the Hershey-Chase experiment, replication, protein synthesis, and genetic mutations based on lecture slides.

Phage

A virus that infects bacterial cells, used in experiments to prove that DNA is the genetic material.

Centrifuge

A machine used to spin a mixture so that heavier components, like bacteria, form a pellet at the bottom of the test tube.

Pellet

The solid material collected at the bottom of a test tube after centrifugation, which contained radioactivity in the DNA-labeled batch of the phage experiment.

Sugar-phosphate backbone

The structural framework of DNA and RNA polynucleotides, consisting of repeating sugar and phosphate groups.

DNA Nucleotide

The building block of DNA, consisting of a phosphate group, a deoxyribose sugar, and a nitrogenous base ($A$, $G$, $C$, or $T$).

Pyrimidines

A class of nitrogenous bases that includes Thymine ($T$) and Cytosine ($C$).

Purines

A class of nitrogenous bases that includes Adenine ($A$) and Guanine ($G$).

Uracil ($U$)

The nitrogenous base found in RNA nucleotides that replaces Thymine ($T$).

Double Helix

The native form of DNA, characterized by two polynucleotide strands wound into a spiral shape, described by Watson, Crick, and Franklin.

Semiconservative DNA Replication

The process where a parental DNA molecule separates and both strands serve as templates, resulting in two identical daughter molecules.

Origin of replication

Specific sites on a DNA molecule where the process of replication begins, forming replication "bubbles."

Transcription

The flow of genetic information from a DNA strand to an RNA strand.

Translation

The process by which the genetic information in RNA is used to synthesize a polypeptide made of amino acids.

Codon

A three-nucleotide sequence in mRNA that specifies a particular amino acid or a termination signal.

Start Codon

The specific codon ($AUG$) that signals the beginning of translation and codes for the amino acid Methionine ($\text{Met}$).

Stop Codon

A codon that signals the end of polypeptide synthesis, such as $UAA$, $UAG$, or $UGA$.

Silent mutation

A mutation in the DNA template that results in no change to the amino acid sequence of the polypeptide.

Missense mutation

A base substitution that results in a slightly different amino acid sequence, such as the change from Glutamic acid ($\text{Glu}$) to Valine ($\text{Val}$) in sickle-cell hemoglobin.

Nonsense mutation

A mutation that causes polypeptide synthesis to cease prematurely by creating a stop codon.

Frameshift mutation

A mutation caused by an insertion or deletion of a nucleotide, which leads to a major difference in the resulting amino acid sequence.