Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Transcript of Bioenergetic Processes
The rate of ATP replenishment can be easily met by aerobic energy production in cells that only have gradual increases in energy
But in muscles, the energy requirement can increase 100x almost instantly
This is a problem, because there's only about 4 mmol ATP stored in muscle (~3 sec worth)
So you must replenish ATP quickly.
ATP-PC (Phosphagen) System
In a nutshell:
ADP + PCr + H
ATP + Cr
note that the reaction goes both ways - law of mass action
About 18-20 mmol of PCr stored in muscle
highest enzyme activity in the entire skeletal muscle
located on the contractile proteins, sarcolemma, SR membrane, in the mitochondria, and free in the cytosol
Wherever ATP is needed, CK is there.
Due to extremely high activity of CK, ATP can be replenished during bursts of intense exercise -
at the expense of PCr
recovery of PCr - half-time ~ 30 sec
- full recovery ~ 6 min
accomplished by aerobic ATP production
Adenylate Kinase (Myokinase)
ADP + ADP
ATP + AMP
Increase in Pi, ADP, AMP, pH
Metabolic pathway beginning with glucose or glycogen
Net production of 2 ATP from glucose and 3 ATP from glycogen
(based on end product)
Aerobic glycolysis -
Anaerobic glycolysis -
pyruvate + NADH + H
lactate + NAD
Most active enzyme in metabolic pathway
5 different isoforms:
H MH M H M H M
*can be altered with training
Different fiber types have different isoforms, based on needs of the muscle cells...
Why convert pyruvate to lactate?
Glycolysis can produce pyruvate faster than it can be used for aerobic energy production
excess precursor for ATP production
Build-up of NADH in cytosol inhibits glycolysis
Converting pyruvate to lactate regenerates NAD, then leaves the cell so it can be used as fuel elsewhere
*rate-limiting enzyme of glycolysis
F-6-P + ATP
F-1,6-BP + ADP
... aka TCA cycle
... aka Citric acid cycle
Fatty acids cleaved from glycerol to form free fatty acid (FFA)
FFA enter mitochondria and begin beta-oxidation spiral
Stored in adipose tissue, liver, and muscle
*rate limiting enzyme of Krebs cycle
isocitrate + NAD
a-ketoglutarate + NADH + CO
5 NADH from glycolysis and Krebs cycle
1 FADH from Krebs cycle
Electron Transport Chain
occurs across/along the inner membrane of the mitochondria
electrons from NADH and FADH are transferred along a series of pumps that move H ions into the intermembrane space
when H ions move back into the mito matrix, ATP is generated
*rate limiting step of ETC
oxygen not required
all the chemical reactions in the body
breakdown and synthesis of molecules
when food is broken down into usable energy
1 g of carbs = 4 kcal of energy
2 conjoined monosaccharides
3 or more conjoined monosaccharides
used for anaerobic & aerobic energy production
1 g of fat = 9 kcal of energy
*not soluble in water, so must have a transporter in blood, etc.
primary type used for energy production
storage form of fatty acids
long carbon chain with carboxyl end group
3 fatty acids attached to a glycerol molecule
primary component of cell membranes and nerve insulation
not metabolized for energy production
Aid in synthesis of hormones and give structure to cellular components
not used for energy production
1 g of protein = 4 kcal of energy
must be broken down into amino acids to contribute to energy production
* NOT A PRIMARY SOURCE OF ENERGY
energy released in the breakdown of one molecule is often used to synthesize another molecule
"exergonic" or "exothermic"
"endergonic" or "endothermic"
regulate speed of reactions
do not cause reactions
work by lowering the activation energy
factors affecting enzyme activity:
Efficiency of system
32 moles ATP/mole glucose x 7.3 kcal/mole ATP
686 kcal/mole glucose
66% lost as heat
metabolic pathway beginning with triglycerides (fats)
1 NADH + 1 FADH per spin
maybe around 2% of total energy production
up to 10% at the end of a long-duration, high-intensity exercise bout
anaerobic out here!
aerobic in here!
- breakdown of adipose
- from adipose to muscle
- into muscle from blood
- prep for catabolism
additional steps get rid of the AMP
turned into pyruvate, acetyl-CoA, Krebs cycle intermediates, or glucose
in extreme heat
this is why we breathe