Essay about Daphnia Lab

1165 Words Apr 16th, 2013 5 Pages
Daphnia and Additives Lab
Purpose
The purpose of this lab is to test what effect of Nicotine, Acetylcholine, Epinephrine, Caffeine, and Ethanol on an organism’s heart rate.
Materials
* Microscope * Eye dropper * Pipet * Cotton balls * Depression slide * Beakers * Daphnia * Water * Five additives: Nicotine, Acetylcholine, Epinephrine, Caffeine, Ethanol
Procedure
1. Put on safety goggles. 2. Catch a living Daphnia. 3. Transfer to a depression slide and add water. 4. Add cotton ball fibers to restrict movement of the Daphnia. 5. Establish the resting heart rate of the Daphnia. Count the amount of beats for ten seconds then multiply that number by six to convert it to beats/min.
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This means that there will be more blood flow to skeletal muscle so the skeletal muscle cells are supplied with more oxygen and respiratory substrates used to generate energy in respiration where it is needed. A drug that increases heart rate is called a positive chronotrope.
One of the ways adrenaline increases heart rate is through the action of what is known as a 'second messenger' or 'transduction component', in this case it is a chemical made in the cell known as cyclic adenosine monophosphate (cAMP). Transduction is the process that follows the action of a drug, hormone or neurotransmitter at a receptor. Thus, when adrenaline activates the beta-1 adrenoceptor in the sinoatrial node, this leads to an increase in cAMP in the sinoatrial node and the result is an increase in heart rate.
Caffeine: Caffeine mimics some of the effects of adrenaline in the heart. Caffeine increases the amount of cAMP in the sinoatrial node. Then cAMP levels increase and this increases the electrical activity of the sinoatrial node, making it depolarize and 'beat' faster. It can affect the main pumping chambers (ventricles), leading to an increase in the rate of contraction and relaxation of each heartbeat. This means that, as well as beating faster, the heart's individual beats are associated with an increased volume of blood ejected into the circulation per unit time (cardiac output). It increases heart rate.
Ethanol: Ethanol slows heart rate. Ethanol

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