Concept 35: DNA responds to signals from outside the cell.

Signal transduction is cell communication that involves a series of molecular transformations.

Growth and development require that cells communicate with each other and react to signals that come from other parts of the body. Notably, hormones released by various glands travel throughout the body to stimulate the growth of certain cell types. Cells capable of being stimulated by a particular hormone possess a specific receptor anchored in the cell membrane. The binding of a hormone to its receptor initiates a series of molecular transformations, called signal transduction, that relay the growth signal through the cell. First, the receptor transduces the signal through the cell membrane to the internal membrane surface, where it activates protein "messengers." These messengers are part of and initiate a cascade of chemical reactions, often involving the addition of phosphate groups. This is the signal that passes through the cytoplasm and into the nucleus. In the final step of signal transduction, DNA binding proteins attach to regulatory sequences and start DNA replication or transcription.

dna binding proteins, dna replication, phosphate groups, regulatory sequences, internal membrane, cell communication, membrane surface, cell membrane, cytoplasm, chemical reactions, messengers, growth and development, glands, hormones, transcription, signals, cells, protein

  • ID: 16724
  • Source: DNALC.DNAFTB

Related Content

1018. Pathways, At the cell surface

In this section learn that a signaling pathway begins with the arrival of a chemical signal – such as a hormone or growth factor – at the cell surface.

  • ID: 1018
  • Source: IC

959. Causes, Smoking: K-ras

This section explains how the protein produced by the K-ras gene is a tumor “activator.”

  • ID: 959
  • Source: IC

16877. Cell Signals

Journey inside a cell as you follow proteins and learn about cellular interactions. This 3-D animation brings to life the inner workings of a fibroblast cell as it responds to external signals. Created by Cold Spring Harbor Laboratory and Interactive Know

  • ID: 16877
  • Source: DNALC

1019. Pathways, Beneath the membrane

In this section learn that the binding of growth factors outside the cell causes receptors ends to intertwine and activate each other, and once active, the modified receptor ends interact with messenger proteins.

  • ID: 1019
  • Source: IC

1022. Pathways, Inside the nucleus

In this section learn that an activated protein is transported into the nucleus through a pore in the nuclear membrane.

  • ID: 1022
  • Source: IC

16725. Animation 35: DNA responds to signals from outside the cell.

James Darnell explains how chemical signals turn eukaryotic genes on and off.

  • ID: 16725
  • Source: DNALC.DNAFTB

1024. Pathways, Releasing the protein

In this section learn that newly made proteins leave the endoplasmic reticulum wrapped in a layer of membrane called a vesicle.

  • ID: 1024
  • Source: IC

1020. Pathways, A bevy of interactions

In this section learn that receptors activate each other before binding an adaptor molecule and an exchange factor.

  • ID: 1020
  • Source: IC

1277. Molecules for Memory

Communication in brain cells is guided by interactions between genes and biochemicals at the synapse. These interactions can lead to the formation of new synapses.

  • ID: 1277
  • Source: G2C

1023. Pathways, Making the protein

In this section learn that in the cytoplasm, the messenger RNA is released from its carrier proteins and binds to a protein assembly complex called a ribosome.

  • ID: 1023
  • Source: IC