Flashcards in Organic Chemistry- Nitrogen- and Phosphorus-Containing Compounds Deck (74)
What 3 elements make up 93% of the human body by weight?
What comprises 3.2% of body weight?
What comprises 1% of human body weight?
What are amino acids?
Dipolar molecules that come together through a condensation reaction, forming peptides.
What are considered proteins?
Larger, folded peptide chains
What is a better description of amino acids?
Containing an amino group and a carboxyl group attached to a single carbon atom (the alpha-carbon). The other two substituents of the alpha-carbon are a hydrogen atom and a side chain referred to as the R group.
The alpha-carbon is what in Amino acids?
A Chiral center
What is the simplist amino acid?
Why is glycine an exception to the amino acids?
Because its R group is a hydrogen atom.
All naturally occuring amino acids in Eukaryotes (except glycine) are what?
Optically active, and all are L-isomers.
How is the Fischer projection of an amion accid drawn?
With the amino group on the left. L-amino acids have (S) configurations.
What amino acid is an exception to the (S) configuration? Why?
Cysteine which is (R) because of the change in priority caused by the sulfur in its R group
Amino acids are what type of molecules? Why?
Because of their acidic carboxyl group and basic amino group
What are amphoteric molecules?
They can act as both acids and bases.
How can amino acids act as both acids and bases?
They can take on a positive charge by being protonated, and carboxyl groups can take on a negative charge by being deprotonated.
When amino acid is put in solution, what does it do?
It will take on both of these charges, forming a dipolar ion or zwitterion.
How an amino acids act s depend on what? Example?
The pH of the environment.
In basic solutions, the amino acid can become fully deprotonated
In acidic solutions, it can become fully protonated.
Each amino acid has properties defined by what?
Its R group
The 20 Eukaryotic proteogenic amino acids can be grouped into what 5 categories?
Negatively charged (acidic)
Positively charged (basic)
Nonpolar nonaromatic amino acids tend to have side chains that are what?
Cyclic with a secondary amine
What amino acids are nonpolar nonacromatic?
Aromatic amino acids include what?
Nonpolar amino acids-- both nonaromatic and aromatic-- are what?
Also hydrophobic and tend to be sequestered in the interior of proteins
Polar amino acids tend to have what?
Terminal groups containing oxygen, nitrogen, or sulfur
What are polar amino acid examples?
What amino acids are included in negatively charged amino acids?
Aspartic acid and glutamic acid
What do negatively charged amino acids have?
Terminal carboxylate anions in their R groups
What amino acids are positively charged amino acids?
What do positively charged amino acids have?
A protonated amino group in their R groups