amino acid, peptides, and proteins Flashcards
What are alpha amino acids? What two function groups do they have?
Molecules that build proteins and enzymes. Carboxylic acid and amino group
How many common amino acids are there are how many are essential?
20 common, 10 essential
What type of amines are amino acids?
Primary, except for one
What is the Zwitterion?
How amino acids are found in nature, O of carboxylic acid has negative charge and amine has positive charge
Do all L amino acids have a stereocenter?
Yes, except for one
What is the stereochemistry of all amino acids?
S
How do we determine if amino acids are D or L?
Location of the amine group in the fisher projection. On the left is L, right is D
What happens when you put an amino acid under acidic or basic conditions?
Acidic- protonates O of carboxylic acid. Charge on amine remained
Basic- deprotonates N of amine. Charge on carboxylic acid O remains charged
Why can you not put carboxylic acid and amine together to form an amine?
Because carboxylic acid is acidic and amine is basic so it forms acid base reactions charging both functional groups
What is the pH of an all protonated amino acid?
1-3, acidic
What is the pH of an all deprotonated amino acid?
8-12, basic
What is the pH of the Zwitterion? What is this point called?
5-7, neutral, isoelectric point
What is the more acidic group of the all protonated amino acid? Why?
OH, it gives off the H first
What are peptides and proteins? What is the difference?
Amino acid polymers. Few= peptide, Many=protein
What are peptides and proteins composed of?
Amino acid units (residues) that are linked by peptide bonds
