Hydrophobic Signal and Control of transcription

Question 1

Define transcription factors

Answer 1

Transcription factors are proteins that when bound to DNA can either stimulate or inhibit initiation of transcription.

Question 1

How do hydrophobic signalling molecules diffuse through the membrane.

Answer 1

Hydrophobic signalling molecules can diffuse directly through the phospholipid bilayers of membranes, and so bind to intracellular receptors. (receptors are in the cytosol or within the nucleus).

Question 2

Examples of Hydrophobic signalling molecules

Answer 2

The steroid hormones oestrogen and
testosterone are examples of hydrophobic signalling molecules

Question 3

The receptors for the hydrophobic signalling molecules are _____________ ________.

Answer 3

The receptors for hydrophobic signalling
molecules are transcription factors