Biology: DNA Structure, Replication, and Protein Synthesis

DNA

Stores genetic information

Double helix

Shape of DNA

Nucleotide

Building block of DNA and RNA

Deoxyribose

Sugar found in DNA

Ribose

Sugar found in RNA

Adenine

DNA/RNA base that pairs with thymine or uracil

Thymine

DNA base that pairs with adenine

Uracil

RNA base that replaces thymine

Cytosine

DNA/RNA base that pairs with guanine

Guanine

DNA/RNA base that pairs with cytosine

DNA replication

Process of copying DNA

DNA polymerase

Enzyme that builds new DNA strands

Semi-conservative replication

Each new DNA contains one old strand and one new strand

Central dogma

DNA → RNA → Protein

Transcription

Making mRNA from DNA

RNA polymerase

Enzyme used during transcription

Translation

Process of building proteins from mRNA

mRNA

Carries genetic instructions from DNA to ribosome

tRNA

Brings amino acids to ribosome

Ribosome

Site of protein synthesis

Codon

Three-base mRNA sequence coding for an amino acid

AUG

Start codon

Protein

Molecule made of amino acids

Amino acid

Building block of proteins

Enzyme

Protein that speeds up chemical reactions

Gene splicing

Removal of introns and joining of exons

Introns

Noncoding RNA sections removed before translation

Exons

Coding RNA sections kept after splicing

Mutation

Change in DNA sequence

Virus

Nonliving infectious particle

Protein coat

Protective outer layer of a virus

Retrovirus

RNA virus that uses reverse transcription

HIV

Example of a retrovirus

Vaccine

Substance that trains immune system to recognize pathogens

mRNA vaccine

Vaccine using mRNA instructions to make viral proteins

Gene regulation

Control of gene expression

DNA packing

DNA wrapping around proteins to fit in nucleus

Promoter

DNA sequence where transcription begins

Enhancer

DNA region increasing transcription

Cell signaling

Communication between cells using chemical signals