DNA, RNA, and Cell Division Lecture Notes

DNA

Stands for Deoxaribonucleic Acid; it carries genetic information for living things.

RNA

Stands for Ribonucleic Acid; it is mainly used as a messenger in making proteins.

Nucleotide

The monomer or building block of nucleic acids, composed of a nitrogenous base, a Phosphate group, and a pentose sugar.

Double Helix

The shape of DNA, consisting of two strands with sugar and phosphate sides and nitrogenous base rungs.

mRNA

Messenger RNA; its job is to carry genetic information.

rRNA

Ribosomal RNA; it makes up the ribosome and is responsible for making proteins.

tRNA

Transfer RNA; its job is to carry amino acids.

Adenine, Thymine, Cytosine, Guanine

The four nitrogenous bases found in DNA.

Adenine, Uracil, Cytosine, Guanine

The four nitrogenous bases found in RNA.

Helicase

An enzyme that unzips the DNA molecule by breaking the hydrogen bonds.

DNA Polymerase

An enzyme that bonds free-floating nucleotides to the growing DNA chain during replication.

Semi-conservative

A descriptor for DNA replication because each new DNA molecule consists of one old strand and one new strand.

Transcription

The process of producing mRNA from a DNA template.

Codon

A sequence of $3$ bases that codes for one specific amino acid.

Start Codon

The specific codon $AUG$ (Methionine) that every protein must begin with.

Stop Codon

One of three codons ($UAA$, $UAG$, or $UGA$) that signals the end of a protein.

Photo 51

The X-Ray Crystallography image taken by Franklin that provided evidence that DNA's structure is a double helix.

Chargaff's Rule

States that for all species, the percentage of Adenine approximately equals Thymine, and the percentage of Guanine approximately equals Cytosine.

Chromosome

A condensed form of DNA produced during cell replication to prevent damage.

Centromere

The middle region of a chromosome where two chromatids attach.

Interphase