Sunday, December 4, 2016

General Mechanism of Photosynthesis


01. Light hits thylakoid membrane.

02. Light energy is absorbed by accessory chlorophyll pigment in light-harvesting complex LH2.

03. Excitation energy passes from pigment to pigment (resonance energy transfer).

04. Excitation energy passes to PRC in LH1's center.
      - PRC: photosynthetic reaction center, where electron transfer reaction occurs,
      similar to electron transport chain in mitochondria.

05. Light energy is absorbed by special pair of chlorophyll.

06. Electron is excited from special pair of chlorophyll A → accessory chlorophyll A
      → pheophytin A → quinone A  quinone B → ultimately out of reaction center.

07. Final electron acceptor: NADP+ → NADPH (reduced).

08. Electron movement creates electrochemical gradient across thylakoid membrane.

09. H+ is pumped from stroma into lumen.

10. H+ flows out of cell to drive ATP synthesis.

11. Cytochrome heme group is oxydized to replace electron loss in special pair of chlorophyll.

12. H20 hydrolysis provides electron to replenish cytochrome and the overall system.

Saturday, September 24, 2016

Dear My Blog's Student Visitors

I never thought my blog would be so often visited because of my MasteringBio contents. Thank you for utilizing them and for expressing your gratitude. It brought my heart so much joy when you told me that they're helpful and that you're thankful. It's the most that I could ever ask for: to aid you in studying for your bio classes. In other words, I hope you would utilize my contents as a tool for success, not a shortcut.

As I progress in my journey toward medicine, starting off as a K-12 student dreaming of caring for others to currently being a premed majored in bio, I realize more and more the importance of knowing the materials by heart instead of trying to get an A and not really knowing the materials.

I would like to share with you an image that I found a long time ago but still, to this day, find it motivational. It's an image that I look at when I feel lost in my seemingly forever journey toward medicine. It's an image that I look at when I doubt myself and my abilities in pursuing medicine. It's also an image that I look at when I ask myself why I'm driven.


And my answer has always been: for the people.

I'm telling you all these because I have my hope for you. You have ups and downs, but I hope you don't always frown. Because you're potential and incredible. Yes, you! You're the one that can make a difference in many. However...

I hope you're pursuing medicine because you would put the people first  instead of fame, money, status, or yourself. I hope you're pursuing medicine because you would like to make the people feel better  instead of making yourself look better. Last but not least, I hope you're pursuing medicine because it's your dream – instead of others' dream for you.

I wish you the best in your journey, not just toward medicine but toward anything that you dream to pursue. Go big or go bigger, then go home knowing that out there you just made a difference!

Sunday, January 17, 2016

Learn to Earn It

I happened to come across an article on Yahoo News just a moment ago and it was talking about 2 criteria that people use to judge us when we first meet them. These criteria, proposed by a Harvard psychologist named Amy Cuddy, are trustworthiness and competence.

The article could be found here:
http://news.yahoo.com/harvard-psychologist-says-people-judge-153500132.html?bcmt=1453051695646-58b17286-2a56-405c-941b-9cfdc7f87445.

But that's not what I wanna talk about, because the article didn't leave me as strong of a relatedness as the one written by a person named Erik. In the comment section, Erik wrote, and I would like to put in bold the phrases that speak to me the most:

__

Everyone has good and bad qualities in them. Nobody is perfect. Our lives and our minds change moment to moment. Even though you think that this person you encountered has good qualities and you become connected with them for years, they can easily become your enemy or someone they didn't seem to be. It goes to say that, once you meet someone, always have an open mind and be accepting to even the not-so-perfect people, because they might be the inspiration and friends that you were looking for.

When I meet someone, I look into their soul and always consider that everyone has the potential for greatness and goodness. But don't get me wrong; sometimes in the back of my mind, I feel like slapping someone silly for his/her arrogance. But that's something I understand and agree with and don't result in taking such actions. Be kind to one another, regardless of race, religion, and gender. Scientifically, we all have the same organs, flesh, skin, and - in a sense - equal to one another. People may have better situations than others', but they choose and create that life for themselves. Nothing is really handed down to you, because you have to work to get what you want - mentally and physically.


__

It's been quite a while for me to find such a long comment like this that I could agree with everything being said. I feel grateful for Erik's comment because it helps me think back deeply into my soul and mind, asking myself whether I had been kind enough and accepting enough to imperfect people, imperfect moments, and even imperfect sides of myself. I love how he said that we should be accepting to imperfection, yet also remember to work hard to get what we want. In other words, it reminds me to continuously work on imperfect sides of myself to earn a better life, because it's not given free to anyone - and by free I mean in terms of more than just currency.

On a side notes, I'm also grateful to learn a new phrase of expression, and that is to "slap someone silly." I thought that he had made a typo, because he had in some parts of his comment - which I already corrected in the one that I wrote down above. But something told me that I should look up the phrase, and so I did, and so I realized that it wasn't a typo but rather a real phrase of saying to slap someone when he/she least expects it and till he/she gets dizzy.

So yea, I have learnt a new phrase of expression today ^__^

Tuesday, December 24, 2013

Video Tutor Session Quiz: DNA Structure

video

Part A
Correct
In this model, the deoxyribose sugar is the blue five-sided structure at the center.
Part B
Correct
A polynucleotide contains a sugar/phosphate backbone, where the sugar of one nucleotide binds to the phosphate of the next, and so on.
Part C
Correct
Remember the base pairing rules: A goes with T, and G goes with C. So the sequence GCAC matches with the sequence CGTG.
Part D
Correct
There are four kinds of DNA nucleotides, abbreviated A, T, C, and G.
Part E
Correct
The sugar and phosphate groups are the same for all DNA nucleotides. The base is the one part that changes.

DNA Packing

Part A
Correct
This is a decondensed DNA double helix.
Part B
Correct
RNA polymerase attaches to DNA.
Part C
Correct
These are histone proteins.
Part D
Correct
This is an image of supercoils.
Part E
Correct
This is an image of loops.

DNA Replication: A Closer Look

Part A
Correct
This is referred to as specific base pairing.
Part B
Correct
DNA replication is semiconservative.
Part C
Correct
The first step of DNA replication is unwinding the DNA double helix.
Part D
Correct
A replication fork is the transition region between paired and unpaired DNA strands.
Part E
Correct
Since DNA polymerase can assemble DNA only in the 5' to 3' direction, the new strand complementary to the 3' to 5' strand must be assembled in short 5' to 3' segments, which are later joined together by ligase.
Part F
Correct
The synthesis of a DNA strand begins with the formation of an RNA primer.
Part G
Correct
An old DNA strand is used as a template for the synthesis of a complementary new strand.

DNA Replication: A Review

Part A

Correct
Ligase joins DNA segments into a continuous strand.
Part B

Correct
DNA replication is semiconservative.
Part C

Correct
The first step of DNA replication is unwinding the DNA double helix.
Part D

Correct
A replication fork is the transition region between paired and unpaired DNA strands.
Part E

Correct
Since DNA polymerase can assemble DNA only in the 5' to 3' direction, the new strand complementary to the 3' to 5' strand must be assembled in short 5' to 3' segments, which are later joined together by ligase.
Part F

Correct
The synthesis of a DNA strand begins with the formation of an RNA primer.
Part G

Question #23

Correct
Primase catalyzes the formation of an RNA primer.
Part H

Correct
An old DNA strand is used as a template for the synthesis of a complementary new strand.