DNA Structure and Gene Function

DNA

A molecule of nucleic acid made of nucleotide monomers that stores the information a cell needs to produce proteins.

Nucleotide

The monomer subunit of DNA consisting of one phosphate group, one $5$-carbon sugar (deoxyribose), and one nitrogenous base.

Griffith’s Experiment

An experiment showing that an unidentified substance could transform a harmless strain of bacteria into a lethal one.

Hershey and Chase Experiment

A study that confirmed DNA, not protein, is the material that contains genetic information using viruses.

Deoxyribose

The $5$-carbon sugar found in the nucleotides of DNA.

Nitrogenous Bases in DNA

Chemical components of nucleotides including Adenine, Guanine, Cytosine, and Thymine.

Double Helix

The three-dimensional helical shape of a DNA molecule formed by two winding strands of nucleotides.

Complementary Base Pairing

The specific matching of nitrogenous bases where Adenine bonds with Thymine and Guanine bonds with Cytosine.

Antiparallel

The orientation of the two DNA strands in opposite directions, relative to their $5'$ and $3'$ ends.

$5'$ (Five-Prime) End

The end of a DNA strand where the phosphate group is attached to the deoxyribose sugar.

$3'$ (Three-Prime) End

The end of a DNA strand where the $-OH$ group is attached to the deoxyribose sugar.

Gene

A small region of a chromosome with a DNA sequence that encodes a specific protein.

RNA (Ribonucleic Acid)

A nucleic acid that is generally single-stranded, contains the sugar ribose, and uses the base Uracil instead of Thymine.

Transcription

The first stage of protein production where RNA is synthesized using DNA as a template.

Translation

The second stage of protein production where a ribosome uses the information in RNA to synthesize a protein.

Messenger RNA (mRNA)

The type of RNA that carries the genetic information from DNA to the ribosome.

Ribosomal RNA (rRNA)

The type of RNA that, along with proteins, makes up the structure of a ribosome.

Transfer RNA (tRNA)

The type of RNA that acts as an adapter, bringing specific amino acids to the ribosome.

RNA Polymerase

The enzyme that unwinds DNA and builds a complementary RNA strand during transcription.

Promoter

A specific DNA sequence at the beginning of a gene where RNA polymerase binds to initiate transcription.

Terminator

A region of DNA at the end of a gene that signals RNA polymerase to stop transcription.

Introns

Sequences within a gene that are removed from the mRNA and are not used to produce a protein.

Exons

The sequences of mRNA that remain after processing and specify the amino acids for the protein.