Learning from National Exams! The Work of a Clinical Laboratory Technician - Let's Classify Amino Acids! -
It has been a while.
This is Akimaru, a clinical laboratory technician.
I have been quite busy with various things, but the 'Learning from National Exams!' series is back!
And I have also refreshed the thumbnail image! I changed it from the simple style I used before to something a bit more exciting. What do you think?
Now, for this time's question,
it is question 37 from the 69th National Examination for Clinical Laboratory Technicians!
Since it has been a while since my last post, this will be a light topic.
So, let's go!
Question
Which of the following are basic amino acids? Select two.
1. Proline
2. Arginine
3. Histidine
4. Methionine
5. Tryptophan
Brief Explanation
This is a question that asks you to remember the structure of amino acids. However, there are over 20 amino acids. Since it is difficult to memorize them all, let's remember a general classification. Mnemonics are also effective.
A mnemonic for basic amino acids is:
The board meeting will be postponed one day.
So, how was it?
Answer
The correct answers are
2. Arginine
3. Histidine
.
Additional Explanation
Amino acids have a carbon atom at the center, with four molecules (atoms) bonded to it. In common schematic diagrams, it is:
Left: Amino group (-NH2)
Right: Carboxyl group (-COOH)
Bottom: Hydrogen atom (H)
. Above, various forms of molecules are bonded as a side chain (R).
The side chains of such amino acids are classified into various types based on the molecules or atoms they contain. I will introduce mnemonics and ways to remember them!
Mnemonic for basic amino acids
Basic amino acids have an amino group in their side chain.
The mnemonic is as follows:
Riji-kai (Board of Directors)...Lysine
aru...Arginine
hi...Histidine
enki...Basic amino acid
Doesn't that seem easy to remember?
Mnemonic (way to remember) for acidic amino acids
The opposite of basic, acidic amino acids have a carboxyl group in their side chain.
Aspartic acidandGlutamic acid
That's it. Only the ones with "acid" in their name! Simple and good! (lol)
Besides acidic and basic, there are classifications such as essential amino acids, branched-chain amino acids, and sulfur-containing amino acids.
Mnemonic for essential amino acids
These are amino acids that are not synthesized in the body.
Tororii-basu fumehi
Tryptophan
Leucine
Lysine
Isoleucine
Valine
Threonine
Phenylalanine
Methionine
Histidine
Just like in classical Japanese, read the "hi" as "i" (lol)
Branched-chain amino acids
Side chains are basically a straight line, but some branch into a Y-shape. These are branched-chain amino acids.
Valine, Leucine, Isoleucine!
Let's remember them by their sound!
Doesn't it feel good because it rhymes? If you pronounce it forcefully, it sounds like German (lol)
Sulfur-containing amino acids
Sulfur-containing means it contains sulfur (S).
The super-sadist tightens it up
S: Sulfide
Cysteine
Methionine
It's kind of exciting, isn't it?
There are also aromatic amino acids, polar amino acids, and non-polar amino acids. That's all for now.
Aside
Amino acid side chains determine protein structure
Three major nutrients - you know them, right?
Nowadays, they are also called energy-producing nutrients.
They consist of carbohydrates, proteins, and fats.
Proteins are broken down into amino acids by digestive enzymes. Conversely, proteins are chains of amino acids.
Amino acids link together by having adjacent amino groups and carboxyl groups hold hands. This connection is called a peptide bond.
You might think proteins just repeat peptide bonds and stay in a straight line... but the side chains also hold hands. Some types of these include:
Hydrogen bonds: between polar groups
Ionic bonds: between acidic and basic groups
Disulfide bonds: between sulfur and sulfur
are some examples.
Imagine gathering about 500 people in a zero-gravity space, having them line up in a row and hold hands. As they float around, people who get along might move closer, or two people might feel attracted to each other, tangling up to create a three-dimensional structure.
This is how proteins with various points in 3D space are born.
By the way, in high school chemistry, I remember learning about the helical structure called alpha-helix and the sheet structure called beta-sheet. At the time, I just thought, 'meh' (lol).
It's a bit complicated, but it's interesting once you study it!
Trolleybus
The trolleybus that appeared in the mnemonic for essential amino acids actually exists. Or rather, it did.
A trolleybus is a mode of transport that is half streetcar and half route bus. It operated at the Kurobe Dam on the Tateyama Kurobe Alpine Route in Toyama and Nagano until the end of 2024.
I wanted to ride the trolleybus to Kurobe Dam, but that dream has become half-unfulfilled...
Strike while the iron is hot.
Let's cherish the present moment and live life to the fullest!
By the way, there is less than a month left until this year's national exam. Good luck to everyone taking it!
So, that's all for this time.
Thank you for watching until the end!
See you in the next article!
This was Akimaru, the clinical laboratory technician. Bye!