How do beta-blockers work? What exactly do antibiotics do to the bacteria they target? What effects does an anti-depressant have on blood flow?

Dssion and assignment on advanced pharmacology

Beta-blockers work by blocking the effects of epinephrine, a hormone that increases heart rate and blood pressure. They specifically block β-adrenergic receptors in the body, which are found in the brain, lungs, heart and other organs. By blocking these receptors, beta blockers reduce symptoms associated with high levels of epinephrine such as chest pain, tremors and anxiety.
Antibiotics work by targeting bacteria to stop them from replicating or producing essential cell components needed for growth. Certain antibiotics can target bacteria’s cell walls or proteins to prevent growth while others interfere with nucleic acid synthesis or cell metabolism.
Anti-depressants act on neurotransmitters such as serotonin to increase their production and balance moods. Studies have also shown that anti-depressants can affect blood flow in certain areas of the brain where serotonin is produced; this increased activity appears to be linked to improved cognitive functioning and emotional well being.