Chapter 4 Flashcards
What are five amino acid derivatives, and what does each example do?
Glycine, GABA, and dopamine- neurotransmitters.
Histamines- mediator of allergic reactions.
Thyroxine- thyroid hormone that regulates metabolism.
What amino acid was GABA synthesized from?
Glutamate/Glutamic acid
What amino acid are histamines synthesized from?
Histidine
What amino acid is thyroxine and dopamine synthesized from?
Tyrosine
What is the isoelectric point (pI)?
The pH at which the net electric charge of an amino acid is zero.
What is a peptide?
Two or more amino acids are covalently linked by peptide bonds.
How are peptide bonds made?
Through a condensation reaction (removal of a water molecule).
What is an oligopeptide?
A peptide whose molecules contain a relatively small number of amino acid residues.
What is a polypeptide?
A linear organic polymer with a large number of amino acid residues bonded together in a chain, forming part of (or all of) a protein molecule.
What are the amino-terminal and the carboxyl terminal of a protein?
What does the amino acid sequence equal?
The protein function.
What is a prosthetic group?
Non-amino acid chemical component of proteins usually plays an important role in protein’s functionality.
What are lipoproteins?
Proteins that contain lipids.
What are glycoproteins?
Proteins that contain sugars.
What are metalloproteins?
Proteins that contain metal ions.
What is green fluorescent protein?
Comes from bioluminescent jellyfish and is used in biotechnology (GFP tagging).
What is glutathione?
Involved in tissue building and repair, making chemicals and proteins needed in the body, and in immune system function.
What is a zwitterion?
When an amino acid lacking an ionizable “R” group is dissolved in water at neutral pH, it exists in a solution as the dipolar ion.
How are disulfide bonds formed in amino acids?
The oxidation of two cysteines. Disulfide bonds stabilize the structures of many proteins.
Which is the only amino acid that is not optically active?
Glycine.
What do Fischer projections do?
Allow stereoisomers to be visualized.
What configuration are all amino acids that are incorporated into proteins?
L-configuration (goes with S configuration).
Which amino acid does not have a chiral center?
Glycine.
What are the building blocks of nature and can be arranged in enumerable ways?
Proteins.
