DNA, RNA, and Gene Expression

A set of flashcards covering key concepts related to DNA, RNA structures, gene expression, transcription, translation, and mutations.

Watson and Crick

Developed the first 3D model of DNA, combining findings from Rosalind Franklin and Edward Chargaff.

Chargaff's Rule

The amount of adenine equals the amount of thymine (A=T) and the amount of cytosine equals the amount of guanine (C=G).

Purines

Nitrogenous bases with a double-ring structure; includes adenine (A) and guanine (G).

Pyrimidines

Nitrogenous bases with a single-ring structure; includes cytosine (C), thymine (T), and uracil (U).

Nucleotide Pairing

Adenine pairs with thymine (2 hydrogen bonds) and cytosine pairs with guanine (3 hydrogen bonds).

DNA Replication

The process by which DNA makes a copy of itself, occurring during the S phase of the cell cycle.

Semi-Conservative Replication

Each strand of the original DNA serves as a template for a new strand, resulting in two DNA molecules, each with one old and one new strand.

Plasmids

Small, circular DNA molecules found in prokaryotes that replicate independently of chromosomal DNA.

Transcription

The process of synthesizing RNA from a DNA template, resulting in mRNA.

RNA Polymerase

The enzyme that synthesizes RNA by transcribing DNA into RNA.

Translation

The synthesis of polypeptides (proteins) based on the sequence of nucleotides in mRNA.

Codon

A sequence of three nucleotides in mRNA that codes for a specific amino acid.

Start Codon

The codon AUG that signals the start of translation and codes for methionine.

Stop Codons

Codons in mRNA that signal the termination of translation; do not code for amino acids.

Gene Expression

The process by which the information encoded in a gene is used to direct the synthesis of a protein.

Alternative Splicing

A process that allows a single gene to code for multiple proteins by including or excluding certain sequences in mRNA.

Epigenetic Inheritance

Changes in gene expression that do not involve alterations to the DNA sequence and can be passed down during cell division.