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.
Science Vocab 147928
