Amino Acids and Proteins Flashcards
What is the central dogma?
DNA to RNA to Protein
What are the three groups that make up an amino acid structure?
Amino group, carboxyl group and an R-group (side chain)
How are peptide bonds formed?
Carboxyl group reacting with the amino acid group from another amino acid.
Standard amino acids are encoded by ______
DNA
Nonstandard amino acids are synthesized by chemical modifications of ___________
Standard amino acids
21st proteinogenic amino acid - coded by a stop codon
Selenocysteine
What polar amino acids are positively charged? (Basic amino acids)
Histidine
Arginine
Lysine
What polar amino acids are negatively charged?
Aspartic Acid
Glutamic Acid
What non-polar amino acid contains a thio (-SH) group, important for disulfide bond formation?
Cysteine
What Secondary non-polar amino acid forms a rigid 5 ring aromatic structure- important in collagen formation in the body?
Proline
What non-polar amino acid has no side chain (only has an H)?
Glycine
What type of side chain has a net zero charge at physiological pH?
Polar
What type of side chain does not gain or lose protons or participate in H/Ionic bonding?
Non Polar
What two non-polar AA’s can lose a proton at alkaline pH?
Cysteine and Tyrosine
What polar amino acid has a side chain that can be either + or neutral charged and acts as a buffer?
Histidine
What 3 polar amino acids have a polar hydroxyl group?
Serine
Threonine
Tyrosine
What polar amino acids have a carbonyl group and an amine group? They also participate in H bonding.
Asparagine and Glutamine
At physiological pH, aspartic acid and glutamic acid have what charge?
Negative- fully ionized
At physiological pH, Histidine has what charge?
Positive- fully ionized
How do non-polar amino acids cluster in a soluble protein?
They cluster in the interior of the soluble protein