Molecular Biology: Melanin Synthesis and Gene Regulation

These flashcards cover key vocabulary related to melanin synthesis, the genetic mechanisms involved in pigmentation, various types of mutations, and gene regulation processes.

Melanin

A pigment responsible for the dark color of skin, hair, and eyes in mammals.

Melanocytes

Specialized skin cells that produce melanin.

Keratinocytes

Skin cells that receive melanin from melanocytes.

TYR

A key enzyme involved in melanin synthesis, derived from the amino acid tyrosine.

a-Melanocyte Stimulating Hormone (a-MSH)

A peptide hormone that activates MITF, leading to increased melanin synthesis.

MITF

A transcription factor that regulates the expression of the TYR, TRP2, and TRP1 genes.

p53 protein

A protein that responds to DNA damage and regulates the production of a-MSH.

POMC gene

A gene that encodes for pro-opiomelanocortin, which is cleaved to produce a-MSH.

Operon

A cluster of genes under the control of a single promoter, often functioning together.

Transcription Factor

A protein that binds to DNA and regulates the transcription of specific genes.

Alternative Splicing

A post-transcriptional process that allows a single gene to code for multiple proteins by varying the way exons are joined.

Eukaryotic mRNA Processing

Includes the removal of introns, addition of a 5' cap and a poly-A tail, before translation.

Cystic Fibrosis

A genetic disorder caused by mutations in the CFTR gene, leading to malfunction of the CFTR protein.

DNA Replication

The process of copying a DNA molecule to produce two identical DNA strands.

Frameshift Mutation

A genetic mutation caused by insertions or deletions that shift the reading frame of the DNA sequence.

Hydrogen Bonds

Weak bonds that hold the base pairs of DNA together, allowing strands to separate during replication.

Topoisomerase

An enzyme that relieves the tension in DNA strands ahead of the replication fork.

MicroRNA (miRNA)

Small RNA molecules that can bind to mRNA to inhibit translation.

UV Radiation

A form of energy that can cause DNA damage and increase melanin production in response.

Regulatory Gene

A gene that codes for a protein (like the repressor) that regulates the expression of other genes.