Amino Acids Practice Quiz

Amino acids are a big deal on the MCAT. You can’t simply ‘get’ the concept. You must be able to quickly recall information and apply them to questions.

The quiz below will help you figure out if you’ve mastered this topic. The questions are simple but thorough. You either know it, or you don’t!

Be sure to review the Amino Acids Tutorial Series and follow along with the Amino Acids Cheat Sheet.

PDF Solutions linked at the end of the quiz

Part 1 – See how quickly you can…

a) Draw the following amino acids

  • Leucine
  • Methionine
  • Phenylalanine
  • Arginine

b) Name the following amino acids

Amino Acid Practice Quiz e Amino Acid Practice Quiz d Amino Acid Practice Quiz c Amino Acid Practice Quiz b Amino Acid Practice Quiz a

c) Classify the amino acids side chains below as one or more of the following:

  • Aliphatic
  • Aromatic
  • Hydrophobic
  • Hydrophilic
  • Acidic
  • Basic
  • Neutral (at physiological pH)

M Q A T W E R K

d) Convert the following amino acids to the correct Fischer Projection

  • Glu to a D Fischer Projection
  • His to an L Fischer Projection
  • R-Tyrosine to Fischer Projection
  • S-Methionine to Fischer Projection
  • R-Serine to Fischer Projection

Part 2 – Amino Acid Characteristics

Which of the amino acids…?
(if more than 1 try to list as many as you can)

  • Rapidly protonates/deprotonates at physiological pH
  • Found on the inside of an alpha helix
  • NOT found inside an alpha helix nor beta sheet
  • Can be used in gluconeogenesis after quick modification
  • Form strong interactions for tertiary/quaternary peptide interactions
  • Found in the middle of a transmembrane protein

Part 3 – Amino Acid Charge

Find the charge of the following amino acids at the given pH

Use the table below for pKa values. Bonus: See if you can answer these questions WITHOUT referring to the table.

His at pH = 6 and 10
Cys at pH = 4 and 8
Gln at pH = 2 and 5

The following polypeptide at pH = 11 AND find its pI – isoelectric point
Tyr-Phe-Met-Arg-Val-Thr-Asp

pka amino acids table

Given amino acid Asp: Rank it’s charge from most positive to most negative when located in the following:
  • small intestine
  • 0.1M NaOH solution
  • stomach
  • dissolved in circulating blood

How do you think you did?

Do you feel you got the questions right? Did you UNDERSTAND how to tackle each questions? See how you did using the link below
Click for Quiz PDF Solutions

Comments

  1. Michelle says:

    Hi Leah, could provide an answer key? Perhaps via email? Thank you! 🙂

  2. Gloria Abbey says:

    Wondering how I can memorize the structures easily

  3. Rafe Mizrahi says:

    Amazing amazing amazing job, I’m itching for the answers now!

    • Leah4sci says:

      Glad you found it helpful Rafe. It was VERY difficult for me to refrain from creating ‘tricky’ questions. Goal here: you know it, or you don’t!

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