| Questions | Answers |
| Q: What is the general structure of an amino acid? | A: An amino group, an alpha-carbon, a carboxyl group, a hydrogen, and an R group. |
| Q: What determines the properties of an amino acid? | A: The side group AKA R group. |
| Q: On an amino acid, what is the charge of the carboxyl group at physiologic pH? | A: Negative. |
| Q: On an amino acid, what is the charge of the amino group at physiologic pH? | A: Positive. |
| Q: At physiological pH the _______ group will be unprotonated and the _______ group will be protonated. | A: The carboxyl group will be unprotonated and the amino group will be protonated. |
| Q: Define zwitterion. | A: A compound with a negative charge and a positive charge on the same molecule. |
| Q: Define amphoteric. | A: A molecule that can act as an acid or a base. |
| Q: The net charge of an amino acid, peptide or protein, will depend upon what? | A: The pH of the surrounding aqueous environment. |
| Q: The negtive log of Ka is known as what? | A: The pKa. |
| Q: True or false? Ka is the association constant. | A: True! |
| Q: What is the isoelectric point (pI)? | A: The isoelectric point (pI) is the pH at which a molecule carries no net electrical charge. |
| Q: A tetrahedral carbon atom with 4 distinct constituents is said to be _______. | A: Chiral. |
| Q: There is one amino acid that is not chiral, which one? | A: Glycine. |
| Q: All of the amino acids in proteins exhibit the same absolute steric configuration as _______. | A: L-glyceraldehyde. |
| Q: Proteins are chains of amino acids linked together by what type of bonds? | A: Peptide bonds. |
| Q: A peptide bond is a covalent bond between the _______ group and _______ group of an adjacent amino acid. | A: Between a carboxyl group and amino group. |
| Q: Name the branched chain amino acids. | A: Isoleucine, Valine, and Leucine. |
| Q: What is the most rigid amino acid? | A: Proline. |
| Q: What is the most flexible amino acid? | A: Glycine. |
| Q: What is the "first" amino acid found in a protein. | A: Methionine. |
| Q: Which amino acids contain ring structures? | A: Phenylalanine, Tryptophan, and Tyrosine. |
| Q: Which amino acid(s) are not optically active? | A: Glycine. It's side group is hydrogen. |
| Q: Are any amino acids neither non-polar nor polar? | A: Yes! Glycine. |
| Q: Which amino acids contain sulfur? | A: Methionine and Cysteine. |
| Q: Which amino acid(s) can form a disulfide bond? | A: A disulfide bond can be formed between two cysteine molecules. |
| Q: Name the polar uncharged amino acids. | A: Serine, Threonine, Cysteine, Asparagine, and Glutamine. |
| Q: Name the polar amino acids with a negative charge. Are these amino acids considered basic or acidic? | A: Aspartate and Glutamate. These are both considered acidic amino acids present in basic form. |
| Q: Name the polar amino acids with a positive charge. Are these amino acids considered basic or acidic? | A: Arginine, Lysine, and Histidine. These are considered basic amino acids present in acidic form. |
| Q: There is one amino acid that is non-polar but has an -OH group capable of forming a hydrogen bond. Which amino acid is it? | A: Tyrosine. Its ring structure makes it non-polar but its -OH allows the hydrogen bond. |
| Q: Phenylalanine contains a benzine ring, what type of ring does tryptophan have? | A: An indole ring. |
| Q: What is glycosylation? | A: Glycosylation is the addition of sugar molecules to certain amino acids in the protein. |
| Q: What is required for glycosylation to take place? | A: You must have a -OH group. |
| Q: Does lipid addition increase or decrease solubility? | A: Decrease! It increases affinity for membranes. |
| Q: What is phosphorylation? | A: The addition of a phosphate group. |
| Q: What do kinases do? | A: They add phosphate. |
| Q: What do phosphatases do? | A: They remove phosphate. |
| Q: True or false? You must have a hydroxyl group for phosphorylation to take place. | A: True! |
| Q: Which amino acids can be phosphorylated? | A: Threonine, Serine, and Tyrosine. |
| Q: True or false? Phosphorylation is reversible. | A: True! |
| Q: In our notes it mentions a "21st" amino acid. Name it. | A: Selenocysteine. |
| Q: This amino acid "puts kinks in things". | A: Proline. |
| Q: She skipped most of the last two pages this section (pgs 2-9 & 2-10). | A: Make sure you read them just in case. Notice the adult (HbA) and fetal (HbF) hemoglobin isoforms. HbA contains alpha & beta, HbF contains alpha & gamma. |
