Amino Acids and Oligopeptides

The video tutorial by Nikolaj covers two main topics: the IUPAC naming of oligopeptides and the structure of lysine at different pH levels. It begins with an introduction to oligopeptides, explaining how to name them using IUPAC rules, including suffix changes for amino acids. The tutorial then provides three-letter and one-letter abbreviations for amino acids like alanine, serine, and lysine. The second part of the video focuses on drawing the structure of lysine at low pH, highlighting how it becomes protonated. The tutorial concludes with a discussion on how lysine's charge varies in different pH environments, from strong acids to strong bases.

What is the term used for a polypeptide chain with fewer than 10 amino acids?

• Tripeptide

• Dipeptide

• Oligopeptide

• Polypeptide

How many amino acids are present in the oligopeptide discussed in the lesson?

• Five

• Four

• Three

• Two

What suffix is used for alanine when naming an oligopeptide?

• Alanyl

• Alaninyl

• Alanil

• Alanin

What is the three-letter abbreviation for lysine?

• LYE

• LYN

• LYS

• LYC

Which one-letter abbreviation corresponds to serine?

• E

• T

• R

• S

What happens to lysine at low pH?

• It becomes negatively charged

• It loses protons

• It gains protons

• It remains neutral

What is the charge of lysine in a strong acidic solution?

• 0

• +2

• -1

• +1

In a weak acidic solution, what is the charge of lysine?

• +1

• 0

• +2

• -1

What is the charge of lysine in a neutral solution?

• +2

• 0

• +1

• -1

In a strong basic solution, what is the charge of lysine?

• -1

• +1

• 0

• +2