Amino acid

Essential amino acids are:

• • amino acids the body can't make, so they must be obtained from the diet.

• • any amino acids your body needs in order to function.

• • amino acids that are found in all organisms.

• • amino acids that are essential to make other amino acids.

Which of the following amino acids is polar?

• • glycine

• • glutamine

• • valine

• • alanine

The three-letter abbreviation for the amino acid asparagine is:

• • arg

• • asp

• • asn

• • agn

How many common amino acids are there that are derived from proteins?

• 5

• 10

• 20

• 30

Amino acids are the building blocks of:

• • lipids and fats

• • proteins and polypeptides

• • carbohydrates

• • nucleic acids

The compound shown on the right is the phenylthiohydantoin derivative of which amino acid?

• A) Alanine

• B) Phenylalanine

• Cysteine

• D) Proline

Which one of the following hydrogen bonds (shown as dotted bonds) best represents the type of hydrogen bond that keep the -helix and the -sheet from falling apart?

• A) O-H·····O=C

• B) O-H·····NH=C

• C) N-H·····NH=C

• D) N-H·····O=C

A pentapeptide was found to have the composition Ala Arg Gly Pro Trp. Reaction of the pentapeptide with Sanger’s reagent, followed by hydrolysis, gave the DNP derivative of proline. Treatment of the pentapeptide with carboxypeptidase initially produced alanine. Treatment of the pentapeptide with trypsin gave a tetrapeptide which, when treated with chymotrypsin, produced a tripeptide. Which one of the following is the sequence of the pentapeptide? (note: trypsin cleaves after basic amino acids)

• A) Pro Gly Arg Trp Ala

• B) Pro Arg Gly Trp Ala

• C) Pro Trp Arg Gly Ala

• D) Pro Gly Trp Arg Ala

What is the structure of the product formed from the reaction between glycine and Sanger's Reagent?

• 
• 
• 
• 

Name the compound below