2. Biochemistry How’d you do?

3. Element Any of the more than 100 known types of atoms An element is designated based on its atomic number (number of Protons) Common elements of organic compounds are H, C, N, O, P, and S

4. Compound A substance formed by the chemical union of two or more elements Compounds can only be broken apart by a chemical reaction Mixtures, in comparison, can be separated without breaking any bonds

5. Covalent Bond A chemical bond that involves sharing a pair of electrons between atoms in a molecule Covalent bonds are the strongest natural bonds Organic compounds are held together by covalent bonds

6. Ionic Bond A chemical bond in which one atom loses an electron and the other atom gains an electron Ionic bonds are weaker than covalent bonds Once the electron is passed from one atom to the other, the two separate easily and are now electrically charged

7. Hydrogen Bond A bond created by the weak attraction of a slightly positive hydrogen atom to a slightly negative portion of another molecule Hydrogen bonds aren’t really bonds at all; just magnetic attractions They hold the two sides of DNA together, but can be separated fairly easily

8. Carbohydrates A compound made up of carbon, hydrogen, and oxygen atoms and includes all sugars and starches Carbohydrates are the most efficient source of energy Sugars supply immediate energy, whereas starches must first be broken down to sugars

9. Lipids Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen Saturated fats are solid at room temperature (butter); Unsaturated are liquid (oils) Lipids store much more energy than carbohydrates because they are larger and have more bonds

10. Proteins A compound that contains carbon, hydrogen, oxygen, and nitrogen needed by tissues for repair and growth Proteins are made of unique combinations of 20 amino acids Proteins make up all Enzymes, which are essential in speeding up chemical reactions

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