AngelT
Forum Senior
Topics: 33
Posts: 111
|
A person eats cookies made with coconut oil. The predominant fatty acid in the TG contained in the coconut oil is lauric acid, which is a saturated 12 carbon fatty acid. Starting with free lauric acid, what is the net energy in high energy-phosphate bonds from each molecule of lauric acid?
a) 83
b) 85
c) 95
d) 97
e) 110
If someone understood this question, please explain me if possible. Thanks!
|
| tompat
Forum Elite
Topics: 39
Posts: 345
|
ok this a weak attempt.
12 carbon atoms will give 6 acetyl coA.
for fatty acid activation we require 2 high energy bonds.
now to make acetyl coA from activated fatty acetyl coA we will get 1 fadh2 and 1 NADH2.this repeats until we split the whole molecule in acetyl coA.
from each acetyl coA we get 3 NADH2, AND 1 FADH2,1 GTP.
so in total we have (5 FADH2+5NADH2)+(6FADH2+18NADH2+6GTP)-2HIGH ENERGY BONDS.
1 fadh2= 2ATPs
1nadh2=3ATPs
after calculations it comes around 95.
so the ans wud be c.
let me know if i m wrong.
|
| drhouse
Forum Elite
Topics: 23
Posts: 209
|
i think u r right tom....
good calculation
___________________
everybody can do it.... its just matter of time
|
| AngelT
Forum Senior
Topics: 33
Posts: 111
|
Yes! The answer is C..!
But from where did you get 5NADH2 and 5FADH2 in the beggining of the calculation?
|
| P4a99
Forum Fanatic
Topics: 44
Posts: 2,426
|
12 carbon atoms ---> 6 Acetyl CoA
5 times through B-oxidation (each cycle gives us 5 ATPs)
6 times through Kreb's cycle (each cycle gives us 12 ATPs)
- 2 ATP for the activation in the beginning
= total 95 ATPs
___________________
2008 Step 1 Study Plan Discussion ..... I am a moderator not a source for download links. Please do not ask me for any.
|
| AngelT
Forum Senior
Topics: 33
Posts: 111
|
Now I got it! Thanks a lot! ; )
|
| dr ruman
Forum Elite
Topics: 32
Posts: 369
|
I STILL CUD NOT UNDERSTAND IT
___________________
Living each day as a preparation for the next is an exciting way to live. Looking forward to something is much more fun than looking back at something—so lets do it together
|
| sfk
Forum Elite
Topics: 47
Posts: 300
|
tompat has made it quite clear, let me make it simpler for you. first of all, going from fatty acid to ATP requires u to know both b-oxid and TCA cycle.
in b- oxid, 1 NADH n 1FADH-2 are fomed at the end of each cycle n acetyl coA is released.
for a 12C fatty acid, 5 such cycles take place, the last cycle will release 2 acetyl coA, making a total of 6 acetyl coA
so 5 b-oxid cycles= 5 NADH n 5FADH2
the 6 acetyl coA by TCA cycle= 18 NADH + 6 FADH + 6GTP
Add all this, n sutract the 2 atp reqd for activation.
hope i didnt confuse u more 
|
| Jlcalisto
Forum Newbie
Topics: 6
Posts: 23
|
Dear friends, i use this formula
FORMULA FOR ATPs DERIVED FROM OXIDATION OF FATTY ACIDS n=number of carbons , N=n/2
ATP=(12xN) + (5x(N-1)) -2
E.g. Lauric 12
N=6
(6*12) + (5x(6-1))-2 = 95
it saves time...
Take care
Good luck
JL
___________________
JL
|
| D_N
Forum Senior
Topics: 33
Posts: 103
|
Thanks JL..
actually works 
|
| SmokyWaters
Forum Elite
Topics: 6
Posts: 447
|
RITO...tompat
|
| sureshrx
Forum Newbie
Topics: 5
Posts: 33
|
good one JL.owe u one
|
|
| |
| | | | | | | | | | | | |
