Question for those of you who remember their biology.

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 3:03 pm

Help me out if you can. I never had biology classes in college, and I'm working off what I learned in 10th grade.

You muscles burn a simple sugar called glucose.

On this glucose molecule there are 8 or 10 ATP? molecules that when broken apart they release a bunch of energy.

I've heard that when you run sprints or do anaerobic exercise, the glucose molecules sent to the muscle fiber don't get totally burned up. Anaerobic oxidation just splits the glucose molecule in half, and a couple of ATPs burn out for energy. The remaining halves of the glucose molecule float around as lactic acid in your muscle tissue.

If what I'm remembering is true:

Question:

Those lactic acid molecules are still full of ATPs that have energy potential. In a following bout of aerobic exercise such as walking, is the lactic acid burned for energy by the muscle?

Or, does the lactic acid just get flushed out of the system as waste?

When it comes to squishy stuff I'm quite ignorant. Any enlightenment would be much appreciated.

Bubba Grizz · Post by **Bubba Grizz** » September 16, 2002, 3:06 pm

damn, you learned that in 10th grade? School has come a long way since I was in. You ever hear of Long Division? Yeah, that's right. Tough one huh.

Fallanthas · Post by **Fallanthas** » September 16, 2002, 3:09 pm

Lactic acid eventually flushes as a waste by product.

Before it does, it's the source of that wonderful ache we all get when working muscle tissue harder than usual.

Gotta love the morning after a serious workout.

noel · Post by **noel** » September 16, 2002, 3:13 pm

The lactic acid gets flushed out of the system as waste. Depending upon your lactate threshhold (LT) (which is a specific heart rate for a given individual), you can generally do areobic excercise below your LT and keep your blood oxygynated enough to keep the lactic acid flushed out of your system. Once you exceed your LT, your muscles will begin accumulate the lactic acid that is unable to be flushed out by newly oxygynated blood, and they will burn until either you stop moving, or lower your exertion and recover.

Good article can be found here.

Or just search google.com on "Lactate Threshold".

The book titled, 'The Cyclists Training Bible' covers all of this extensively.

noel · Post by **noel** » September 16, 2002, 3:14 pm

Fallanthas wrote:Lactic acid eventually flushes as a waste by product.

Before it does, it's the source of that wonderful ache we all get when working muscle tissue harder than usual.

Gotta love the morning after a serious workout.

Lactic acid is NOT a factor the morning after a serious workout. Lactic acid does not contribute to the pain in muscles the following day. Lactic acid will only be a factor during excercise.

Sore muscles != lactic acid.

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 3:16 pm

What a shame.

That's a lot of potential energy to be throwing out.

Voronwë · Post by **Voronwë** » September 16, 2002, 3:17 pm

been awhile, so forgive any errors, but giving you best guess answer to what i think is your question.

i assume you are getting at whether more vigorous excersize is in fact the most efficient, or something to that effect.

well, during vigorous excersize your muscles aren't necessarily going anaerobic. that depends on your cardio-pulmonary health really. if you are cramping up during vigorous excersize, then yes those muscles are going anaerobic (lactic acid buildup causes the cramp).

but yes the yield of Aerobic respiration is LOTS more than anaerobic, which is why Eukaryotic organisms dominate.

Anaerobic Respiration nets 2 ATP (used to fuel various processes)
Aerobic Respiration nets 38 ATP once you kick in all the NADH and FADH2 yielded from Kreb's cycle.

but if you are in good shape, your muscles will continue to operate under aerobic conditions even during vigorous activity.

noel · Post by **noel** » September 16, 2002, 3:18 pm

Adex, I'm a pretty active cyclist, so if you have a specific question, let me know and I'll try to help.

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 3:26 pm

Well, The question that prompted me asking was.

If you are sore, and the day after you begin to jog or such. Are you burning that leftover lactic acid, or are you just flushing it away.

CAN the body process lactic acid for energy?

Body processes tend to be well designed. My gut was telling me that the body had a way to burn lactic acid.

I just wanted to know the truth of the matter.

ALSO, can anyone find a pic of a glucose molecule and speak a bit about what the ATP parts look like?

thanks again

Voronwë · Post by **Voronwë** » September 16, 2002, 3:31 pm

ATP is not attached to glucose at all.

you can think of glucose as kind of like a ring of 6 carbon molecules. these bonds are broken one by one and energy is released. that energy is converted by the biochemical machinery of the cell into what is called a high energy phosphate bond.

ATP = Adenosine Triphosphate
ADP = Adenosine Diphosphate

ADP + Energy + PO4 (phosphate) = ATP

ATP + a protein that is doing work = ADP + Phosphate + completed work

ATP is just what is used by the little protein engines in cells to get shit done. basically like gasoline for them.

your muscles are sore the day after workouts because there was damage done to them and they are being repaired. as aranuil said, the pain from lactic acid is only during the excersize itself.

noel · Post by **noel** » September 16, 2002, 3:32 pm

Adex_Xeda wrote:Well, The question that prompted me asking was.

If you are sore, and the day after you begin to jog or such. Are you burning that leftover lactic acid, or are you just flushing it away.

CAN the body process lactic acid for energy?

Lactic acid is a waste product only. If you are sore the day following vigorous excercise, the soreness you are feeling is not from lactic acid, but from torn muscle fibers that are repairing themselves. The pain caused by lactic acid will only be felt during excercise, either aerobic or anaerobic.

Fallanthas · Post by **Fallanthas** » September 16, 2002, 3:32 pm

Hrmm, I had always understood that the low grade ache from a workout was a result of lactic acid buildup.

Are you saying this isn't correct, Aranuil?

Note I am not referring to 'overworked' muscle groups, just that general achey feeling you get after slacking for a while and getting started again.

Next you will tell me potassium doesn't help combat the problem!!

noel · Post by **noel** » September 16, 2002, 3:37 pm

I am 99% sure that lactic acid plays no part in post excercise soreness. If you can find evidence to the contrary, I'd love to see it. I'd rather learn the correct information than just think I'm right.

Potassium prevents muscle cramping and also helps with hydration.

Protein/Branch Chain Amino Acid intake with copious amounts of water is the best way to help recovering muscle recover faster.

Incidentally, for anyone who is doing serious endurance excercise, I highly recommend the Endurox R4 drink for post excercise recovery. Yes it tastes like ass (though the flavor has grown on me), but it works extremely well as a post excercise recovery drink. I always drink this within 15 minutes of getting off the bike. It would work for runners, swimmers etc. though.

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 3:46 pm

Ok I found a ATP molecule diagram.

A couple questions:

Which bonds on this molecule contain all that high power energy when broken?

Voronwe, there's 38 of these on a glucose molecule? Where?

Voronwë · Post by **Voronwë** » September 16, 2002, 3:55 pm

the high energy bond is the left most phosphate.

the 38 ATPs dont come directly from glucose bonds breaking.

Glucose is broken into 2 pyruvate molecules. Pyruvate undergoes all sorts of modifications during the Kreb's Cycle.

it is the production of the NADH and FADH2 that result in the big yields of ATP later on.

They are run through the Electron Transport chain, and a massive bioelectric potential gradient is buillt up inside the Mitochondria, and that is used to drive ATP synthesis.

here are some cartoons.

http://www.sp.uconn.edu/~terry/images/anim/ETS.html

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 4:02 pm

Ah cool!

Thanks V,

Voronwë · Post by **Voronwë** » September 16, 2002, 4:04 pm

no problem, helps me justify the remaining $27k i have on my BS and MS in biology to pay off

Adex_Xeda · Post by **Adex_Xeda** » September 16, 2002, 4:10 pm

You know, the most amazing thing about all of this is, that a little bit of sunlight radiated on a leaf, can be trapped, converted, packed away in a energy-dense form, unpacked, stripped down and released in my cells.

We are like the ultimate solar powered vechicles.

I mean, even the stuff that lives off thermal vents at the bottom of the seabeds get their energy from energy deposits from the sun during the time when the earth was forming.

It all traces back.

A single causation. Once source for all of this.

It gives you a newfound appreciation that ole orange disk in the sky.

Truant · Post by **Truant** » September 16, 2002, 4:54 pm

I remember the Kreb's cycle!
I actually enjoyed learning about that.

kyoukan · Post by **kyoukan** » September 16, 2002, 4:56 pm

aranuil shaves his legs

noel · Post by **noel** » September 16, 2002, 4:56 pm

Innkubbus · Post by **Innkubbus** » September 16, 2002, 11:12 pm

Don't know if anyone said this yet but the energy is in the bonds of the ATP molecules. When those bonds are broken (made into lactic acid) the energy is gone.

Drasta · Post by **Drasta** » September 17, 2002, 12:37 am

damn ....next time i have a project for school i know where i am going ...