A-mean-O Acids
Provide the Structure @ pH=7, Name, and 3 Letter Code for... W
Trp, Tryptophan
a Hydratase is what class of enzyme?
Lyase NOT Hydrolase!
I have: 5 NADH, 11 FADH2, 3 GTP, 7 NAD+, 4 FAD++.
How many ATP equivalents is this?
32 ATP
Is the following polypeptide isoelectric at pH = 7?
CHEMISTRY
Yes
No if you put a charge on histidine (which is fine)
What is something other than studying you can do to help yourself be prepared for the test.
Examples:
exercise
eat a good breakfast
get a lot of sleep the night before
stay hydrated
Provide the 1 letter codes, the names, and the structure of the following @ pH=7:
Ala-Lys-Tyr
AKY
Alanine-Lysine-Tyrosine
What class of enzyme would be responsible for turning an alcohol to an aldehyde and back again?
oxidoreductase
cAMP is a messenger molecule which is crucial to controlling cell replication. What cofactor is often couple to other reactions with cAMP if most enzyme involving cAMP are kinases?
GTP
Is the isoelectric point of the following polypeptide above or below or about 7: VILLAIN
its at about 7
Which is typically the easier type of test question:
Recognition - ie multiple choice
Recall - ie draw the following
Which one should you study more to be more prepared?
Study to recall more! If you can produce information from memory then you already have recognition covered too!
Examples of recall studying are:
- drawing/
- teaching someone else
- writing out an explanation
- creating your own problems
Examples of recognition studying are:
- flashcards that show you the picture first
- reading and copying
- sequencing
Provide the names, 3 letter codes, and draw the structure of the following at pH=12:
FAIL
Phenylalanine-alanine-isoleucine-leucine
Phe-Ala-Iso-Leu
What is the substrate of bisphosphoglycerate-mutase.
Bonus 100 pts if you can tell me what it does to the substrate or the class of enzyme.
Substrate is bisphosphoglycerate.
Mutases are isomerases, so this enzyme isomerizes bisphosphoglycerate.
Consider Linoleic acid. Imagine that instead of using Pt/Pd/Ni, I used an enzyme to saturate it. What cofactor would likely need to be present and how many of it would be needed to fully saturate it?
2 FADH2
I want to make the following peptide isoelectric: DADDY.
pKa of aspartate = 4
pKa of glutamate = 4.5
pKa of lysine = 11
pKa of arginine = 12
pKa of histidine = 6
pKa of cysteine = 8
pKa of proline = 10
pKa of asparagine = 8.75
I currently have in distilled water. What chemical should I add to make it isoelectric? H2SO4 or NaOH
H2SO4.
@ pH 7 (distilled water) this polypeptide has a net charge of -3. So I need to add + which means add H which means lower pH so I need to add an acid.
What type of the problems should you try to tackle early on a test if you're worried you won't finish the whole test in time?
The ones that are worth the most points
Provide the names, 3 letter codes, and draw the structure of the following at pH=1:
SHREK
Serine-Histidine-Arginine-Glutamate-Lysine
Ser-His-Arg-Glu-Lys
Which of the following doesn't belong:
synthetase
kinase
hydratase
Hydratase (doesn't involve ATP)
Methotrexate is a cancer drug which prevents the regeneration of dihydrofolate from folic acid.
I have beaker with a solution of the enzyme dihydrofolate reductase and methotrexate and folic acid. I measure the amount of dihydrofolate as I add more folic acid. In the beginning there is no dihydrofolate but as I add folic acid I find more and more dihydrofolate.
Who is the substrate, who is the inhibitor and what kind of inhibitor is it?
Methotrexate is the competitive inhibitor and folic acid is the substrate.
Draw the following polypeptide at its isolelectric point and give a pH where this might occur: FREE
pKa of aspartate = 4
pKa of glutamate = 4.5
pKa of lysine = 11
pKa of arginine = 12
pKa of histidine = 6
pKa of cysteine = 8
pKa of proline = 10
pH 3 could be isoelectic for this polypeptide
You are faced with a test question and it is SOOOOO long! You are getting overwhelmed. You skip it but you come back and it's still freaking you out. What is a strategy to help you handle it?
Some examples:
- take some deep slow breaths
- find the actual question or direction (ie draw this, name this, what is the...) and circle it.
- circle all the single words you do recognize and think about what kinds of problems have used those words in the past
Draw the structure of the following at pH=3: (draw each as a separate (poly)peptide)
pKa of aspartate = 4
pKa of glutamate = 4.5
pKa of lysine = 11
pKa of arginine = 12
pKa of histidine = 6
pKa of cysteine = 8
pKa of proline = 10
LIVING IN A PRAYER
Check with Erika
The following multistep reaction occurs, what sequence of enzymes would catalyze the process. (Hint there are 4)
I start with a secondary alcohol, which then becomes a ketone. That ketone is then moved to the end of the molecule becoming an aldehyde. That aldehyde becomes a carboxylic acid, which then has an ethyl group added to it to create an ester without the use of ATP.
sec.alcohol to ketone: oxidoreductase
ketone to aldehyde: isomerase
aldehyde to carboxylic acid: oxidoreductase (again)
carboxylic acid to ester: transferase
Nitric oxide binds cytochrome-C-oxidase which is the last enzyme in the electron transport chain. The body produces nitric oxide to control blood pressure through a multistep cascade by limiting metabolism and forcing blood vessels to relax. Cyanide, a famous poison, also interacts with cytochrome C oxidase resulting in death. In a few sentences explain why these two chemicals have such drastically different results even though they impact the same enzyme.
Nitric oxide is a reversible inhibitor which allows the body to resume metabolism as needed. Cyanide is reversible, metabolism ends permanently which results in death.
What is the isoelectric point of the following polypeptide: SKIP
pKa of aspartate = 4
pKa of glutamate = 4.5
pKa of lysine = 11
pKa of arginine = 12
pKa of histidine = 6
pKa of cysteine = 8
pKa of proline = 10
10 (average 11 and 9)
You are feeling an absurd amount of stress leading up to your test. Name 3 things you can do to handle the stress besides study or go to OH etc. Something not chem related.
Examples:
- call a loved one
- eat/drink something you enjoy
- meditate (ie with the headspace app)
- exercise/workout
- listen to some music
- take regular study breaks
- verbally correct negative self talk (ie I'm never gonna get this gets rewritten as I don't understand this right now but that doesn't mean I won't understand it later)