Molecular Biology: Central Dogma, Biotechnology, and Protein Analysis

Comprehensive vocabulary flashcards covering the Central Dogma, gene regulation, recombinant DNA cloning, PCR and qPCR analysis, Sanger sequencing, hemoglobin variants, and protein analytical methods.

Central Dogma

The principle describing the flow of genetic information: $\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$.

DNA

The molecule that stores genetic information and functions as a permanent instruction manual.

RNA

The working copy of a gene that carries instructions from DNA.

Protein

Molecules that perform the actual work in the cell, functioning as enzymes, receptors, and structural molecules.

Replication

The process that copies the entire genome before cell division using DNA polymerase to produce DNA.

Transcription

The process of making RNA from a single gene using RNA polymerase, copying only selected genes.

Enhancers

Regulatory DNA sequences that act like volume knobs to control how strongly a gene is expressed; more enhancer activity leads to more gene expression.

Alternative Splicing

The process where RNA is cut and assembled in different ways, allowing a single gene to produce multiple proteins.

Restriction Enzymes

Proteins described as "DNA scissors" that cut DNA at specific sequences (such as EcoRI cutting at EcoRI sites).

Sticky Ends

Overhanging ends produced after restriction enzyme cutting that easily pair together like puzzle pieces to help insert DNA into plasmids.

Plasmid

A small circular DNA molecule used as a vector to carry genes.

Origin of Replication (ORI)

A mandatory plasmid element that allows the copying and replication of the plasmid.

Antibiotic Resistance Gene

A plasmid feature that helps identify bacteria that have successfully taken up the plasmid.

Cloning Site

The specific region in a plasmid where a gene of interest is inserted.

DNA Ligase

The enzyme responsible for sealing the inserted DNA into the plasmid during the cloning process.

Polymerase Chain Reaction (PCR)

A technique used to make millions of copies of DNA, doubling the DNA with each cycle according to $\text{Copies} = 2^n$, where $n$ is the number of cycles.

Reverse Transcriptase

An enzyme that converts RNA into DNA ($\text{RNA} \rightarrow \text{DNA}$).

RT-PCR

A technique that uses reverse transcription followed by PCR to answer: "Is this gene being expressed?"

qPCR

Quantitative PCR that measures amplification in real time to answer: "How much is this gene expressed?"

$Ct$ Value

The cycle threshold in qPCR; a lower $Ct$ indicates more initial starting material and higher gene expression.

$\Delta\Delta Ct$ Fold Change

A comparative quantitative formula in qPCR calculated as $\text{Fold Change} = 2^{-\Delta\Delta Ct}$.

Dideoxynucleotides (ddNTPs)

"Stop nucleotides" used in DNA sequencing that immediately halt DNA synthesis upon addition because there is no place for another nucleotide to attach.

$\alpha$-globin

A protein subunit component of hemoglobin.

$\beta$-globin

The main component of adult hemoglobin; individuals with sickle cell disease harbor a mutation in this globin.

$\gamma$-globin

A fetal hemoglobin component found at high levels in newborns and low levels in adults that is protective against sickle-cell pain crises.

Sickle Cell Disease

A genetic disorder caused by a mutation in $\beta$-globin; patients with elevated $\gamma$-globin experience fewer pain crises.

SDS-PAGE

A method that answers "How big is the protein?" by separating proteins according to size, where small proteins move farther and large proteins move less.

Coomassie Stain

A blue dye that binds to proteins to show what proteins are present across an entire gel.

Immunoblot (Western Blot)

A detection method that uses antibodies like "search dogs" to answer: "Is this specific protein present?"

Isoelectric Focusing

A technique that answers "Do proteins have different charges?" by separating proteins according to their $pI$.

Isoelectric Point ($pI$)

The specific pH at which a protein carries no net charge.

2D Gel Electrophoresis

A high-resolution protein separation method that separates proteins sequentially by two distinct properties: charge ($pI$) and size ($MW$).