Friday, June 13, 2008

The Idiot's Guide to DNA & GENOMICS
Structure of DNA

The Structure of DNA

1. The Double Helix
  • 2 polynucleotide chains (or DNA strands) twisted around each other to form a double helix
  • The 2 strands are antiparallel (run in opposite directions: 5' to 3' and the other, 3' to 5' end)
  • Held together by hydrogen bonds between nitrogenous bases of opposite strands (complementary base pairing)

2. Complementary base pairing

  • The pairing of a purine and pyrimidine by formation of hydrogen bonds
  • A forms 2 bonds with T, C forms 3 bonds with G
  • Ratio of A:T=1:1, C:G=1:1 (for obvious reasons) So why does RNA have screwed up ratios? Beause it exists as a single strand, thus complementary base pairing cannot occur.

3. Measurements just know point 1

  • Each complete turn has 10 base pairs
  • Each complete turn spans 3.4nm
  • Width of a base: 1nm (constant width throughout the sugar-phosphate backbones is 2nm then.)

4. Differences between DNA and RNA

  • Read page 10 of your notes! Lol. In fact read everything from page 10 onwards.

I hope all that was useful for your foundation for DNA.

Thursday, June 12, 2008

Your Bio Rep posts godly notes.
LOL.
Joking.
All my bio notes will come under the label: Bio Notes.

The Idiot's Guide to DNA & GENOMICS
The fundamental facts

Actually I wanted to just do DNA replication and not the fundamental facts (which will have to do if you're doing DNA replication).
From my senior's experience, the chunk before DNA replication on your DNA notes won't be tested, but I feel you've to know them or else you'll get lost.

Here we go.

FUNDAMENTAL FACTS
Get this memorised and done with. It works wonders.

1. Nucleic acids
  • 4th type of biological molecule (carbohydrates, proteins, lipids, nucleic acid)
  • 2 types: Deoxyribonucleic acid and ribonucleic acid
  • Stores and transmits genetic information
2. Nucleotide
  • A nucleotide is the basic unit of a DNA/RNA. Many many nucleotides joined together becomes a DNA/RNA strand.
  • For DNA it is called deoxyribonucleotide. For RNA, it is called ribonucleotide.
  • Consists of a pentose sugar, a phostate group and a nitrogenous base.

-Pentose sugar:

  • Pentose meaning there are 5 carbon atoms. 4C and 1O are linked in pentose formation, while carbon atom 5 protrudes out by a bond to carbon atom 4.
  • In deoxyribonucleotides, carbon atom 2 is bonded to 2 hydrogen atoms.
  • In ribonucleotides, carbon atom 2 is bonded to 1 H atom, 1 hydroxyl group (-OH). Which makes sense since they named them DEOXYribonucleotide and ribonucleotide.

-Phosphate group:

  • Gives the nucleic acid its acidic properties.
  • Drawing a phosphate group: P atom having 3 single bonds to O atoms (which means the O atoms are charge -1), 1 double bond to O atom.
  • Realise that it is actually phosphoric acid, but the phosphate group is what we want to lock into our minds.

-Nitrogenous bases (2 types)

  • Purines: Adenine and guanine
  • Pyrimidines: Thymine, uracil and cytosine
  • In short: DNA - ATCG, RNA - AUCG (T in DNA always replaced by U in RNA)

3. Formation of nucleotides

  • Pentose sugar, phosphate groups and nitrogenous bases go through condensation reactions.
  • Nitrogenous base (A,T/U,C,G) attached to carbon atom 1 of pentose sugar (OH from carbon atom 1 and H from nitrogen atom of base is removed as 1 water molecule)
  • Phosphate group is attached to carbon atom 5 (OH from carbon atom 5 and H from one of the single bonded O atom is removed as 1 water molecule) now you know why you drew it as O-.

4. Formation of polynucleotides

  • Via condensation reactions, carbon atom 3 of each nucleotide is attached to an O- of the phosphate group of another nucleotide.
  • Thus there will be a sugar-phosphate backbone on one side, and nitrogenous bases on the other side.
  • 5' end of the polynucleotide ends with a phosphate group attached to carbon atom 5 while the 3' end of the polynucleotide ends with hydroxyl group of carbon atom 3 sticking out alone (because no phosphate group condensed with it).

AWESOME.

With awesomeness,

Bio Rep.

GP Reminder #2

1 Gay
2 Fatin
3 Joel
4 Sam Ho
Submit your global warming compre papers

5. Melvin, submit your global warming essay

Submit in Mrs Khemani's pigeon hole, BY SATURDAY
For ALL:
GP Meeting: Monday 2pm, LT6 to take back scripts and any other stuff to do with the exams.
4th June Wednesday

CLASS CIP!!!!!!!!!!!

omg it was damn funfunfunfunfun hahahahaha
doing cip as a class is always damn fun agreed? xD
omg i simply love my cls to bits <33
let me try recall the events of that day..

Me jiahui mark samlam daryl ellie jocelyn huishan yiming cuixia met at bugis mrt
we were waiting for the ppl to pass us the badges
so meanwhile we did some camwhoring hahahaha
omg i think im figgin pro at taking candid shots LOL
so many ppl is after my camera now to delete their candid photos xD

me and yonglit head off to city hall to try our luck thr..
most hilarious thing was a european man donated 5buck for two badges..
smth which wiped out the 3 bades for 3bucks yonglit sold earlier on LOL
so i wiped his record in 1min smth he spent 4hrs earning LOL i pity him haha

in the end i manage to sell ard 50 badges..
quite ok la consider the luck of other boys xD
the girls combined to sold a total of 89 badges not bad xD

abt 7:45 headed back to bugis to meet up with the rest..
and after depositing our badges and money collected..
it was well a session of camwhoring all the way -.- haha
ate dinner at the food junction whr everything was EX..
then more camwhoring and then it was home sweet home
hahahahaha omg i love every single outing i have with my cls lols

samlam huishan ellie yiming
Samuel Lam, Hui Shan, Ellie, Yi Ming
Lols i wanted to post a candid shot of Hui Shan..
but being such a nice guy i shall spare her haha xD
she knows which photo i talking about xD

jiahui (centre)
Some girl i donno: Yesterday I went to Lakeside to -
Jiahui: OMG melvin shocked me. Don't ever do that again.

Photobucket
Me in action trying to sell my badges lols
I manage to sell this lady 3 badges xD

Photobucket
They bought 2 badges haha.
Oya the photographer is yonglit in the bushes trying failing to hide LOL

yonglit!!
Yong Lit: Mm.. Mmmmm.. Yum. Mummy bai for mee...

badges
Badges that we had to sell [but failed to]

Ellie!! xD
Ellie xD
I edited the photo already..
but i have no idea why its still at this angle haha

huishan ellie yiling
Samlam's arm, Hui Shan, Ellie, Yi Ming

Photobucket
The group of us who went to sell badges..

jiahui ellie
Jia hui and Ellie THIS IS CANDID

samlam LOL
Lols Samuel Lam's posed version of a candid shot haha
THIS IS POSED CANDID (as oxymoronic as fat-thin)

yonglit mark
Yong Lit and Mark..
Aww how loving they are hahaha xD

Jealously is brewing...

yiming cuixia
Yi Ming and Cui Xia xD
Btw all photos from here on are taken by Jocelyn lols

yonglit eating xD
Yong Lit eating

mark!
Mark eating

daryl eating!
Daryl eating

samlam eating
Sam Lam grieving over dead tofu.

yonglit =.=
yong Lit's version of emo =.=
Yong Lit: I've got awesome chest and abs.

daryl samlam
Sam Lam eating his erm perverted looking ice kachiang lols

girls from our class
The class' girls who went for cip shift 2

Photobucket

huishan
Random shot of Jiahui and Huishan

yiming
Candid shot of Yi Ming xD

yiming
Pretty cool shot right xD

huishan and yiming candid shot HAHA
Hui Shan: I bitchslap you ah... Hahaha.
Yi Ming: Hehehehe you think you very funny is it. Siao ding dong.

The best candid shot of the night xD
Just as Hui Shan and Yi Ming were abt to whack me up..
CLICK and i took this hilarious shot hahahaha
OH NO huishan pls don't kill me during future pw meeings XD
__________________________________________________

Lols here are more photos and videos of our previous class outing!!
For more photos of tat outing please visit Jia Hui's blog hahaha =D


Sam Lam dancing hahahahaha
Yea though this looks super reatarded..
he is actually almost scoring a perfect game lols o.o



LOL YONG LIT DANCING PARAPARA HAHAHAHAHA XD
lols the reason why the camera keeps shaking was becos i cld not stop laaughing LOL





Omg you MUST watch the whole of this video omg its friggin hilarious also
you will know why after watching this video and the next one lols


Lols after watching the previous video guess wad??
I just wasted 25 seconds of your life hahahahaha XD
Anw this was wad Sakae Sushi had to offer..
Eggs eggs eggs eggs and MORE EGGS LOL XD


MORE EGGS HAHAHA xD

Sam Lam!!
Sam Lam lols

Yonglit samlam and samho
Sam ho the driver lols with sam lam and yonglit as passengers o.o

Photobucket
Samho: She's gorgeous -
Samlam: Oh the nine hells we are gonna crash STOP TH -
Yong Lit: Sian. want to look at gorgeous woman then now gonna crash. haiz.

Eunice and Jenni
Lols Eunice and Jenni xD
A shark suddenly attacked them and they screamed like donno wad..
LOL XD

Empty plates of sushi xD
We occupied two tables in sakae sushi...
this amount of plates were just from one table LOL
Imagine how much we ate lols omg hahaha

Photobucket
Sam lam in another of his poses XD

Photobucket
Jia hui and Sam ho playing some zombie game..
Jia hui was screaming agian XD hahaha

I will be posting 2 more videos tmr.
They are taking a hell long time to upload zz..
1 video of jiahui and samlam playing at a arcade
1 video of some funny incident in the mrt
stay tuned XD

Wednesday, June 11, 2008

HI 1SC6 IM BACK BLOGGIN hahahaha
after my stupid com blew up while chatting with kristy and fatin online abt PW =.=

Updates for this Friday Environment CIP!!!
Those who signed up pls confirm with me you are going thanks!!

Be in school by 9:30AM
Go to Viewing Gallery!!
Thr will b a coach to sent us thr.
Wear collegiates with school bottoms.
Brink dark shorts.
3 NTUC type plastic bags for collecting rubbish
A glass/plastic bottle, with label peeled off for Terrarium workshop
Stationaries
$5
Water bottle
Change ofclothes
Bring camera if u wish.
Cip will end around 6pm.
We will have dinner tgt after that!!!!
I donno the person-in-charge name lols but his number is 81839823

yupyup see you peeps this friday!!
My Mother's Turtlenecks. By Wallace Kirkman. Age: sixteen.

My mother loved my father and hated her neck. She thought it was too... fleshy or something. If I hated my neck, I'd have it removed! But, she never trusted doctors. And so she wore turtlenecks... all the time. In every picture we have of her, she's wearing a turtleneck. She had turtlenecks in every colour of the rainbow. She had blacks, she had whites, she had grays, and plaids, and polka-dots, and hounds tooth checks, and stripes, and mickey mouse! And even sort of a... mesh turtleneck.

I can't imagine her without a turtleneck on. Although ACCORDING TO FREUD, I try to... Every moment... of everyday...

We have a picture of me when I was a baby wearing one of my mother's turtlenecks. Hmf, swimming in one of my mother's turtlenecks is more like it. Just a bald head... and a big shirt... It's very erotic... in an... Oedipal... shirtwear sort of way.

It's a rare photograph. Because I'm smiling. I never smiled all that much during my childhood... I'm taking lessons now, trying to learn again. But it takes time.

I stopped smiling when my mother stopped wearing turtlenecks. I came home... from a typical day in the second grade, to find her, taking a bath... in her own, blood. On the kitchen floor. Her turtleneck was on the kitchen table, so it wouldn't come between her neck... and her knife.

I then understood why she wore turtlenecks all along. To stop the blood from flowing. To cover the wound that had been there all along. They tried to cover the wound when they buried her with one of her favourite turtlenecks on. But it didn't matter then. It was an empty hole by then. My mother wasn't hiding inside.

She wrote a note before she died, asking to be cremated. And I asked my father why she wasn't. He said my mother was two women, and the one he loved, would have been scared... of the flames.

I look at that photograph of little me inside my mother's womb. It's the closest I can get to security. There are no pictures of me inside my mother's womb... But her turtleneck... Her turtleneck... is close enough.

The monologue 'My Mother's Turtlenecks' from 'Women and Wallace'.

Thank you everyone who came and wanted to come for Theasthai, and for the everyone else who has supported me (by laughing at all my drama in class). I am proud and happy for my results.

I WILL POST BIO NOTES SOON AFTER THIS.

Tuesday, June 3, 2008

GP Reminder

Fatin
Jenni
Gayathri
Eunice
Joel
Sam Ho
Melvin
Mark

Global warming compre scripts better be in Mrs Khemani's pigeon hole in the STI before Thursday, when she goes and pick it up.

As receipt of reading this, pls sms/email me.
Thanks, Alex

Monday, June 2, 2008

hey ho! kristy here. gg to confirm some stuff regarding class cip here. i know it's quite a pity that all of us can't do a shift altogether. but i'm sure all of us will still have fun doing our shifts right, we can still bond a bit!:D so here are the groupings, please double check if you need to.

WEDNESDAY 4TH JUNE 2008
Shift 1: 12pm-4pm
please kindly meet at harbourfront control station at 11.10am(:
Alex
Peihoon
Jim
Sam Ho
Fatin
Gay
Kristyn
Kristy (in-charge)
Yonglit

Shift 2: 4pm-8pm
please kindly meet at harbourfront control station at 3.10pm(:
Ellie (in-charge)
Jenni

Jocelyn
Cuixia
Jiahui
Huishan

Yiming
Sam Lam

Melvin
Zi Jian
Daryl
Mark

what to wear: anything decent. don't need to wear school based shirts.

hmm 4 hours may seem long but we should bear in mind that we're doing this street sales to help the Student Advisory Centre. since we're given this CIP opportunity, we should do what we can and at the same time, have great fun doing this meaningful activity together too! when you are selling the badges, shirts and notebooks, do realise that you're contributing to the society and that's a good deed!

inevitably, there will be people who will treat us like transparent glass and ignore us. but please don't be disheartened alright? at least we're doing our part to help the society. moreover, we can continue finding MORE people on the streets. yup so never give up! every effort counts, really(: just keep smiling and be polite!

some tips:
  1. always smile!
  2. be brave and ask politely
  3. have confidence in your products? hahaha
  4. please call aunties "xiao jie" *******important********

okay i truly believe that every one of us is important in this fundraising activity. so come on, let's give our best to help our beneficiaries k! see you all on wednesday then we'll have fun:D

Sunday, June 1, 2008

Candid moments(:

Candid shots (from handphone)

Tuesday, May 27, 2008

TERM NUGGEST part 1

Mondae 23/6
GP H1 0900-1030
GSC H1 1300-1540
Chinese H1 1300-1600
Tuesdae 24/6
Math H2 0900-1030
Chem H2 1300-1430
Wednesdae 25/6
Econs H1 0815-0915
Geog H1 1300-1400
Thursdae 26/6
Bio H2 0815-0945
Lit H1 1300-1530
Fridae 27/6
TSD H2 0815-1015
Phy H1 0815-0945
Mondae 30/6
Hist H1 0900-1030
CSE H1 1230-1330

hi people


hi people.
seeing how absolutely around the corner terms are.
ur dearest and sweetest acl has decided to help u in ur revision!!
weeeee!
hahahaha
(but actually thats cos im freaking bored)

so this is an incentive for those who visits class blog dutifully & frequently & v weak in chem
ok here are basically some stuff that she might not have gone through in class

1. COVALENT BONDING WITH 2ND ROW ELEMENTS
- elements with 1 to 4 electrons in their valence shells form the same no. of covalent bonds as
the no. of valence shell electrons
- elements of 2nd period with more than 4 electrons in their outer shells form (8-n), whereby
n=no. of valence shell electrons

this is because elements of the 2nd row of periodic table have 4 orbiatls in their valence shell (2S, 2Px, 2Py, 2Pz) <--- note: only 8 electrons in valence shell, hence cannot accomodate more than 4 pairs of electrons

2. COVALENT BONDING WITH 3RD ROW ELEMENTS
- 3rd & subsequent rows can utilise their d orbitals in bonding as well as s and p orbitals (3s, 3p,3d) <--- note can have 18 electrons in valence shell (2n^2), hence can form more than 4 covalent bonds to other atoms

3. lone pair is an area of -ve charge & thurs forms the delta -ve end of a dipole

4. Isoelectronic molecules & ions
-Definition: has same no. of electrons, same no. of bonded & non-bonded electron pairs in their
valence shells
- Isoelectronic molecules/ons all have same basic shape & identical bond angles

5. Double bond: 4 electrons in this bond count as one group of electrons (used in VESPR)


the above information is reliable to a certain extent
cos it comes from our chem txt book.
i.e. Chemistry for advanced level by peter cann & peter hughes

so yes. i hope that this helps u guys alot!
all the best for terms!
and may u guys score especially well for chem!! :DDDD

~XOXO jia :D