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!
PDF Solutions linked at the end of the quiz
Part 1 – See how quickly you can…
a) Draw the following amino acids
b) Name the following amino acids
c) Classify the amino acids side chains below as one or more of the following:
- 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
- small intestine
- 0.1M NaOH solution
- 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