BIOL 190 - DNA and RNA Structure, Replication, and Biotechnology

Vocabulary practice flashcards covering DNA/RNA structure, enzymes of replication, types of mutations, epigenetics, and biotechnology based on the Week 9 lecture notes.

Nucleotides

The nucleic acid monomers or units containing a nitrogen-containing base, a sugar group (Deoxyribose or Ribose), and a phosphate group.

Pyrimidines

Single-ring molecules with carbon, nitrogen, oxygen, and hydrogen; includes Cytosine ($c$), Thymine ($t$), and Uracil ($u$).

Purines

Molecules consisting of two rings with carbon, nitrogen, oxygen, and hydrogen; includes Adenine ($a$) and Guanine ($g$).

Genes

Certain nucleotide base sequences in DNA that code for making proteins; they make up only $2\%$ of human DNA.

Non-coding DNA

The $98\%$ of the human genome (approximately 3 billion base pairs) that does not make protein.

Antiparallel

A characteristic of DNA strands where one strand goes "up" and the other goes "down" relative to each other.

5 prime (5')

The end of a DNA strand characterized by a phosphate molecule ($p$).

3 prime (3')

The end of a DNA strand characterized by a hydroxyl group or oxygen-hydrogen ($-OH$) molecule.

Helicase

The enzyme responsible for unzipping the DNA double helix during replication.

Single-strand binding proteins

Proteins that keep the DNA unzipped and stable while it is being replicated.

DNA polymerase III

The enzyme that reads the DNA template and adds DNA nucleotides to the RNA primer.

DNA polymerase II

The enzyme that "proofreads" the DNA template to reduce mistakes and repairs DNA.

DNA polymerase I

The enzyme that replaces the RNA primer with DNA nucleotides at the end of the replication process.

RNA primase

The enzyme that adds RNA primers to the new strands to initiate replication.

Ligase

The enzyme that stitches DNA segments together on the new strands.

Leading Strand

The new DNA strand that is synthesized continuously in the $5' \rightarrow 3'$ direction.

Lagging Strand

The new DNA strand synthesized in the $3' \rightarrow 5'$ direction, which the DNA polymerase cannot move down easily, resulting in discontinuous addition.

Okazaki fragment

Short, separated blocks of nucleotide bases (composed of an RNA primer and a short DNA section) added to the lagging strand.

Silent mutation

A point mutation where the nucleotide change does not have an impact on the protein produced.

Missense mutation

A point mutation where the DNA change results in a different amino acid sequence in the protein; for example, Sickle Cell Anemia.

Nonsense mutation

A point mutation where a substitution results in an early stop in the protein chain production, such as in Cystic Fibrosis.

Frameshift mutation

A mutation caused by the insertion or deletion of a nucleotide base, shifting the entire pattern of the protein sequence.

Mutagen

A chemical or high-energy source that manipulates DNA chemistry and increases the risk of cancer (carcinogen).

Epigenetics

The study of how environment and behaviors in a lifetime can change how genes function without changing the actual DNA sequence.

DNA methylation

An essential tool to turn off genes by adding a methyl ($-\text{CH}_3$) group onto a nucleotide.

Histone proteins

Proteins around which DNA is normally tightly coiled; modifications to these can release or overtighten DNA to change gene expression.

Transgenic

Any organism that has a foreign gene from another species inserted into its genome, such as Bt Corn.

Bioremediation

The use of genetically modified organisms, such as oil-degrading bacteria, to clean up the environment.

CRISPR-Cas9

A cheap, easy, and extremely accurate gene-editing technology based on bacterial natural defense systems against viruses.

dCas9

A modified Cas9 protein used to target and influence the epigenome (activating or repressing genes) without changing the DNA sequence itself.