BIO Reading Genetic Diseases #2

Gene Regulation

Mechanisms that turn on certain genes while keeping other genes turned off in a particular cell.

Gene Expression

The flow of genetic information from DNA to RNA to protein.

X Chromosome Inactivitation

When one X chromosome in female mammals in each body cell is highly compacted and almost entirely inactive. This ensures that males and females have the same number of active X genes.

Transcription Factors

A protein that functions in initiating or regulating transcription. Bind to DNA or to proteins that bind to DNA.

- a type of gene expression control.

MicroRNAs

A type of gene expression regulation when small RNA molecules bind to mRNA molecules, preventing them from producing protein.

Signal Transduction Pathway

A series of molecules changes that converts a signal received on a target cell's surface to a specific response inside the cell.

Development

The growth of an animal from an embryo into an adult. Involved frequent cell division to increase body size.

Core Question:

How can one gene be responsible for a very large effect, such as establishing which end of the body is the head?

One homeotic gene can produce a protein that turns groups of other genes on or off.

Induction

A mechanism that occurs when one group of cells influences the development of an adjacent group of cells.

Homeotic Genes

Master control genes. Determines the identity of a body structure of a developing organism, presumably by controlling the developmental fate of groups of cells.

In a developing embryo, they produce protein signals that turn groups of other genes on and off.

Tumor

When a cell occasionally loses the ability to control its cell cycle (like from a mutation). This results in a mass of body cells that is growing out of control. If this spreads to other tissues, the person has cancer.

Cancer

The spreading of a tumor to other tissues.

Cell Cycle Control System

The process within each cell that regulates the timing of cell duplication. A cyclically operating set of proteins that triggers and coordinates events in the cell cycle.

Oncogene

A gene that leads to uncontrolled cell growth. A mutated version of a proto-oncogene.

Proto-oncogene

A gene that produces a protein that normally regulates the cell cycle.

- ex: growth factor protein

Growth Factor

A type of protein that is produced by a proto-oncogene that stimulates cell division. A mutation in this gene can result in a hyperactive protein that promotes cell division when it should not, creating a tumor.

Tumor-suppressor Genes

A gene that normally codes for proteins that inhibit cell division. A mutation here would create uncontrolled growth.

Core Question:

How could the duplication of a gene result in cancer?

If that gene produces a growth factor, duplication of the gene may result in overstimulation of growth.

Metastasis

The spread of cancer cells from their origin to sites distance in the body.

Malignant Tumor

A tumor that has genetic and cellular changes that enable it to spread to other parts of the body. This causes cancer and this spread if called metastasis.

What are some ways to prevent cancer?

1. Healthy Diet

2. Not smoking

3. Sun protection

4. Regular screenings

5. Exercise

How do you treat cancer?

1. If it is benign, surgery to remove it is sufficient.

2. If it malignant, radiation removes it locally and

3. chemotherapy destroys it throughout the whole body.

Radiation Therapy

A type of cancer treatment that exposes specific areas of the body to high-energy radiation. This disrupts cell division and slows down or kills cancer cells, but damages normal cells.

Chemotherapy

Drugs that disrupt cell division through the bloodstream This affects cells throughout the whole body which causes negative side effects like hair loss and nausea.

Core Question:

Why is metastatic cancer much harder to treat than non-metastatic cancer?

After metastasis, the tumor has spread to multiple locations, making it much harder to treat with surgery or radiation.

Benign Tumor

An abnormal mass of cells that remains at its original site in the body.