chapter 15

Prokaryotes

Organisms that lack membrane-bound organelles.

Eukaryotes

Organisms, including plants and fungi, that have membrane-bound organelles.

Central Dogma of Molecular Biology

The process in which DNA is transcribed into RNA, which is then translated into protein.

Transcription

The process of synthesizing RNA from a DNA template.

Operon

A set of functionally related genes controlled by a single promoter.

Repressor

A protein that binds to an operator to prevent gene expression.

Lactose Operon

A set of genes necessary for the metabolism of the disaccharide lactose.

Lactase

An enzyme that breaks down lactose.

Glucose

A simple sugar that is preferred over lactose for energy production.

Gene expression regulation

The process by which cells control the amount and timing of the appearance of the functional product of a gene.

Chromatin structure

The organization of DNA and histones that influences gene transcription.

Activator

A protein that increases gene transcription by binding to an enhancer or promoter.

CAMP

Cyclic AMP, a signaling molecule that can activate certain genes in the presence of glucose.

RNA Polymerase

An enzyme that synthesizes RNA by transcription of DNA.

Histones

Proteins that DNA wraps around to form chromatin.