During which portion of the electrocardiogram do the atria contract

Answer;

- P-R interval

Explanation;

-P-R interval is the period of time from the onset of the P wave to the beginning of the QRS complex . This period normally ranges from 0.12 to 0.20 seconds in duration.

-The P-R interval represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. A prolonged PR interval indicates delayed conduction of the sino-atrial, or SA, nodal impulse to the ventricles and is called first-degree AV block. A short PR interval can be seen when the AV node delay is bypassed.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure

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