what is the greatest thing that you know? what is the greatest thing that you have done?

Answer 1

As a Scientist, I get asked many questions as I am sure you understand. Of course I have to protect my identity. I allow the mundane world to address me as Dr. Nucleus. The nucleus being the heart of the atom, I found that title particularly (pun intended) fitting. The following is the greatest thing I know and sharing it with the world (and now you) is the greatest thing I have done.
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Dear Doctor Nucleus,

Although I want to become a great Scientist like you, I don't have the money or grades to attend some prestigious institution for years to get my degree. Help me, please! How can I get the Scientific education that I want and need?

Concernedly,
Edward Showen Teller

Dear Teddy,

A Scientist does not need a highfalutin university to confer some worthless scrap of ram's epidermis upon him. To a Scientist candidate, the whole world is an education.

If your time is limited, the most direct route to greatness would be home study. Get up late in the afternoon, mornings are for non-Scientists, and brew yourself a pot of triple strength coffee. Drink it all; Science has no half measures. Time for breakfast! Stock up on Captain Crunch, Twinkies, and more coffee. Now stare into the mirror and chant, "Science is Truth -- Truth is Science" for about an hour. This will get you close to the mind state where your brain is ready to receive great Truths.

Find a TV station showing movies about great Scientists, preferably those of Bert I. Gordon ("The Amazing Colossal Man" and "Earth Vs. the Spiders”.) Set an electric fan, turning at precisely 60 rpm, in front of the screen and watch the movie through the turning blades. This stroboscopic effect simulates "cat naps" which all great Scientists must take. Sleepy? Time for more coffee and, for health reasons, microwave popcorn.

Be a Scientist, act the part! Write down all observations in steno notebooks. Mutter to yourself. In bookstores' Science sections, fling books off shelves and scream "Lies! Lies! Damnable lies!" Soon you will get the respect you deserve.

Scientifically,
Dr. Nucleus

Answer 2

1. Kreb’s Cycle
Glycolysis:
6C glu à 3C pyruvate x2
Glu + 2NAD+ + 2 ADP + 2 Pi à 2 pyr + 2 NADH + 2 H+ + 2 ATP + 2 H2O

D Go’ = -85 kJ/mole

2 NADH à e- transport à ATP synth (16-1)

In cytosol

3C Pyruvate Product

2 C’s added to Coenzyme A (CoA)(16-3)

As acetate group

Activates CoA (thioester)

1 C as CO2

Pyruvate Dehydrogenase
Complex (PDC)

Catalyzes acetylation CoA (16-2)

Oxidative decarboxylation (LEO + cleave carboxylate)

In mitochondria

3 associated enz’s

Pyruvate dehydrogenase

Dihydrolipoyl transacetylase

Dihydrolipoyl dehydrogenase

5 cofactors

PDC E1: Pyruvate Dehydrogenase

24 copies in complex (E. coli)

Cofactor: thiamine pyrophosphate (TPP) (15-9)

PDC E1: Pyruvate Dehydrogenase

Pyr binds à ethanolic grp att’d to TPP

CO2 released

Ox’n to acetaldehyde w/ transfer to E2

PDC E2: Dihydrolipoyl
Transacetylase

"Core" of complex

24 copies (E. coli)

Cofactor: lipollysyl (16-4)

Molecular "arm"

In ox’d form – 5 membered ring w/ disulfide

Ethanolic grp att’s here, ox’d à acetaldehyde

-S-S- red’d to –SH HS- w/ ox’n to acetaldehyde

Thioester

Site of attack by CoASH

Transesterification

à AcetylCoA + dithiol lipoyl

PDC E3: Dihydrolipoyl
Dehydrogenase

12 copies att’d to E2 (E. coli)

Cofactor: FAD

REMEMBER: Flavin nucleotide cofactors bound to enz’s

Nicotinamide nucleotides cofactors freer to dissociate

Used to reoxidize lipollysyl

FAD red’d à FADH2

Lipollysyl ox’d à ring w/ disulfide

FADH2 regen’d by NAD+ entry

FADH2 ox’d à original FAD

NAD+ red’d à NADH

Leaves complex

Where might it go?

PDC Summary

3 Enz’s closely assoc’d

Acetyl grp physically transferred

Regulatory

Both allosteric + covalently modified regulation

E1 has kinase, phosphatase enz’s assoc’d

Kinase phosphorylates, inactivates

Phosphatase dephosphorylates, activates

Assoc’d kinase allosterically controlled

ATP stimulates

Act’d kinase inactivates PDC

So ­ [ATP] à ?? PDC??

Modulators (16-15)

Inhibitory: ATP, NADH, acetyl CoA, fatty acids

Why??

Stimulatory: ADP/AMP, NAD+, pyruvate, CoA

Why??

Kreb’s Cycle

= Citric Acid Cycle = Tricarboxylic Acid Cycle = TCA Cycle (16-11,16-7)

2 C’s from pyr (as acetyl on acetylCoA)

2 C’s leave as CO2 (not same 2 C’s that entered)

4 redox rxn’s

3 NAD+ à 3 NADH; 1 FAD à FADH2

Where will these go?

1 high energy phosphate bond formed

1 GDP à 1 GTP (some cells 1 ADP à 1 ATP)

REMEMBER the name of this phosph’n?

Oxaloacetate regen’d

REMEMBER: 2 turns for each glu

Up to 38 ATP/glu (>1160 kJ/mole avail)

1 step uses complex sim to PDC

Acetyl CoA + Oxaloacetate
à Citrate + CoASH

Citrate Synthetase

Condensation rxn

CoASH regen’d

Through CH3 of acetyl

Transient intermediate: citroyl CoA (p.573)

Energy rel’d from cleavage acetylCoA

Why? What grps impt to exergonic rxn?

Oxaloacetate binds first (16-8)

à Conform’l change

Now site for acetylCoA

Modulators (16-15)

Availability of substrates

Inhib’n w/ ­ [citrate]

What type of inhib’n?

­ [citrate] also inhibits PFK-1

Where is PFK-1?

What type of inhib’n would this be?

Inhib’n w/ ­ [ATP]

Relieved w/ ­ [ADP]

Why?

Inhib’n w/ ­ [succinyl CoA]

Feedback inhib’n

Citrate à Isocitrate

Aconitase

Isomerization

Cis-aconitate intermediate

Iron-sulfur center (16-9)

Isocitrate à a Ketoglutarate
+ CO2

Isocitrate Dehydrogenase

Ox’n rxn

NAD+ or NADP+ depending on isozyme

Regulation (16-15)

Inhib’n w/ ­ [ATP]

Inhib’n w/ ­ ratio [NADH]/[NAD+]

Why?

a Ketoglutarate à
SuccinylCoA + CO2

a Ketoglutarate
Dehydrogenase Complex

Identical rxn to PDC

Similar E1, E2, E3 enzymes

Same cofactors

NAD+

Regulation (16-15)

Inhib’n w/ ­ [succinyl CoA]

Inhib’n w/ ­ ratio [NADH]/[NAD+]

SuccinylCoA à
Succinate + CoASH

SuccinylCoA Synthetase (16-10)

+ Pi à high energy acyl phosphate intermediate in enz active site + CoASH released

Phosphate transferred to enz active site His

GDP enters active site; phosph’d à GTP

Substrate level phosph’n results

Book: GTP formed transfers PO4 to ADP later

Succinate à Fumarate

Succinate Dehydrogenase

Membr-bound

Euk’s – inner mitoch membr

Prok’s – plasma membr

Impt also in e- transport

FAD may be cov’ly bound

Fumarate à L-Malate

Fumarase

Hydration trans across db

Enz stereospecific

L-Malate à Oxaloacetate

L-Malate Dehydrogenase

Substrate limited rxn

Large + D G

Why does the rxn go?

Cycle

Complete w/ regen’n oxaloacetate

Amphibolic

Impt to both catabolism (breakdown) and anabolism (build-up) of cell’s molecules

Catabolism of carbohydrates, FA’s, aa’s through pyruvate, acetylCoA(17-8; 18-14) à Kreb’s à ATP

Anabolism by cycle intermediates à aa’s, fa’s, lipids, purines/pyrimidines (16-13)

Balance of amphibolic pathways through anapleurotic rxns (16-13)

Replenish cycle intermediates so TCA remains constant

4 impt rxns (Table 16-2)

Synth oxaloacetate or malate from pyruvate or phosphoenolpyruvate

Where did you see these reactants?

If ­ ­ ­ glycolysis (so ­ ­ ­ PEP/pyr products), but not enough oxaloacetate to fuel cycle

Cell can use excess PEP/pyr to make more oxaloacetate

Now have sufficient to react w/ excess acetylCoA (from excess pyr, from excess PEP)




2. Love someone with all my heart and passion

Answer 3

i know the greatest that we will respect our mother father and teacher and our nation .the greatest thing i done that i consider my god is father and mother

Answer 4

Nothing is the greatest thing..and i did nothing that is the best part!!!!!!!! lol

Answer 5

1)newtons 3rd law-every action has a equal and opposite reaction.
and about DNA .......it controls everything
2)i love and trust my parents and my friends.coz trust is important in any relationship.....

Answer 6

That Jesus Christ died for me!!!

Accepted Jesus as my Savior!!!!