A. A. A stress test can be used to test for heart disease. Stress tests are tests performed by a doctor and/or trained technician to determine the amount of stress that your heart can manage before developing either an abnormal rhythm or evidence of ischemia (not enough blood flow to the heart muscle).
The four types of organic compounds are carbohydrates, lipids, proteins and nucleic acids. Organic molecules contain the elements carbon and hydrogen, and they are found and made in living things. Keep Learning.
The last class of organic molecules are the nucleic acids. There are two varieties: ribonucleic acid, or RNA, and deoxyribonucleic acid, or DNA. These polymers are long chains of components called bases, of which there are only five types. RNA is a single-strand molecule; DNA is a spiral of two cross-connected strands. DNA carries information. Part of the DNA in a cell is genes, which code for protein molecules. Each type of receptor, or enzyme, or neurotransmitter, has a stretch of DNA in which its sequence of amino acids is coded. The code-to-primary-structure ratio is three-to-one: three bases (called a codon) per amino acid.