1Substance A is synthesized in the liver travels through the

1.Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.

2.Protein kinases ____.

3. Ras proteins are of interest to researchers because of their role in ____.

4. Neurotransmitters are molecules released by ____.

5. Loosely packed regions of DNA associated with histones are called ____.

Solution

QUes-1:

paracrine signaling

Reason:

Proteins (for example, Ras proteins) are synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. A cell responds only to signaling molecules that are targeted to that specific cell. However, sometimes signaling molecules can cross the cell membrane (paracrine signaling, neuronal signaling) without acting on receptor & finally can trigger cellular response. The signaling molecules are going to target specific cells to exert their amplifying signal by transmitting to the interior proteins finally trigger downstream events in multicellular organisms.

Ques-2: add phosphate groups to proteins

Reason:

Protein kinases are proteins that promote phosphorylation in which, these enzymes are going to add phosphate groups to proteins. Phosphorylation cascades \"directly\" cannot result in stimulation of gene expression because \"protein kinases\" & \"protein phosphatases\" during phosphorylation/dephosphorylation trigger secondary messenger proteins activities to act on the gene expression. Therefore, these cascades do not directly stimulate gene expression.

Ques-5:

euchromatin

4. Neurotransmitters are molecules released by

Neurons