Fuel for exercise Flashcards
substrates
something that enters a pathway
-carbohydrate, fat protein, glucose, fatty acids, amino acids
products
something that is made from the pathway
-use fuels to make energy - ATP
metabolism
chemical reactions in the body usually performed by enzymes
bioenergetics
process of converting substrates into energy
-converting fuels into stored energy (ATP)
fuel is a ____ and ATP is a ____
substrate; product
energy is ___ in the ___
stored in the phosphate bonds
ATP is ____energy
stored
when phosphate is dropped then we get energy
ATP–ADP–AMP
ATP =
ADP+ enegy+ Pi+ heat
1 calorie =
heat energy required to raise 1g of water from 14.5 c to 15.5 c
1 kcal (Calorie) =
heat energy required to raise 1 kg of water 1 C
substrates we convert to energy (ATP) using ___
bioenergetics
substrates we convert to energy (ATP) using bioenergetics
carbohydrates, starches, fatty acids, protein, amino acids
NOT fiber
Myosin
breaks bond (cross-bridges) between myosin head and actin-binding spots
-ATPase
Na+-K+ pump (within cell membranes like sarcolemma)
enabling RMP to return from repolarization
-ATPase
Ca2+ pumps (within sarcoplasmic reticulum (SR) membrane)
SR “vacuums” up all sarcoplasm Ca2+
-otherwise, you wouldn’t be able to relax (lengthen) your sarcomeres (muscle)
-troponin and Ca presence
-ATPase
using fuel to make more ATP to continue muscle contraction
substrates
where are the bioenergetics pathways to make more ATP to continue muscle contraction
sarcoplasm -creatine, glycolysis
mitochondria - beta oxidative, krebs cycle
ATP is not energy, but it
stores energy
energy is stored in high-energy
phosphate bonds
Energy currency
ATP— ATPase–ADP (because of de-phosphorylation)–then phosphorylation to make it ATP again
breaking a high energy phosphate bond to release stored energy
de-phosphorylation of ATP
ATP+H20 =
ADP + pi + energy
hydrolysis is a
chemical reaction
ATPase releases energy from high energy
phosphate bonds
most common hydrolysis reaction
H20+ ATP + energy +pi +heat
absence of O2 =
substrate phosphorylation of ADP
-creatine
-glycolysis - PFK and PK enzymes
-Krebs cycle - SCS enzyme
presence of O2 =
oxidative phosphorylation
Electron transfer chain only uses
ATP synthase enzyme
three ATP synthesis pathways
-ATP-PCR system
-glycolytic system
-oxidative system
oxidative system (only ETC uses O2)
- beta-oxidation
- krebs cycle
- ETC
creatine is not consumed but
recycled to carry phosphates
phosphocreatine is used to re-make ATP from
ADP
carbohydrates have ___kcals per gram
4
glycogen stored in cyostol but in the muscle it is stored in
sarcoplasm
primary fuel for the nervous system
brain and nerves
fuel for RBC is
glycolysis
glycose is only substrate for
glycolysis
glucose comes from
blood, diet, liver glycogen
-locally from glycogen
fat kcal
9
because oxidative pathways are slower
ATP demand has to be lower for slow supply to match
lipolysis
breaking down lipids
made in the mitochondria
beta oxidation, krebs, ETC
beta oxidation
takes fatty acids and breaks it down to Acety-CoA
Krebs cycle
converts ADP to ATP
-acetyl Coa — OAA
ETC
oxidative phosphorylation
low glycogen =
increase use of fat as fuel
Protein kcal
4
amounts of protein used
2-5% at rest – up to 8% during exercise
all amino acids have to be ______ before bioenergetics
de-aminated
amino acids in bioenergetics are
glucose, pyruvate, Acetyl-CoA
pyruvate and lactate are
carbohydrates
pyruvate in first converted back in the ___ then ___
tissues and then mitochandria
pyruvate can be converted back to glucose in ___
glucogenesis
mass action effect
substrate availability affects enzyme activity
-more available substrate = higher pathway activity
real limiting enzymes
pathways can only produce as much product as the slowest enzyme
glycolytic RLE
hexokinase -HK
phosphofructokinase - PFK
Pyruvate Kinase - PK
-these dictate how much ATP is made
if RLE’s are stimulated
more atp is made
if RLE’s are inhibited
less ATP is made
controlling bioenergetics through
negative feedback loops
substrate level phosphorylation
krebs cycle and beta-oxidation
where do you make ATP PCr system
sarcoplasm with substrate PCr
glycolytic pathway
sarcoplasm with substrate glucose
oxidative pathway
mitochondria with substrate Acetyl CoA and RE
-includes beta-oxidation, krebs cycle, ETC
PCr energy can be used to
reassemble ATP
PCr energy can be used to
reassemble ATP
phosphocreatine (PCr)
Atp recycling
Ck activity dictates the
rate of ATP production
when ATP levels are down
ADP LEVELS ARE UP AND CK IS UP
when ATP levels are up
CK activity is down
low intensity: ATP levels dont drop much, so CK activity
is low
high intensity: ATP level drop quite a bit, so CK activity
is high
fast pathway: glycolysis
reliant on glucose availability
-found in the sarcoplasm
-no O2
how much ATP produced for 1 glucose
2-3 ATP
glycolysis catabolizes glucose to
pyruvate
-1 glucose = 2 pyrvuate
ATP yield for glycolysis
2 ATP/ 1 mol glucose in blood
3 ATP glucose from glycogen
-lasts for as long as glucose is available
glucose carbon number
6
1st step of glycolysis
phosphorylate glucose
-requires phosphorylate from the hydrolysis of ATP and ADP
-blood glucose to glucose 6-phosphate = hexokinase
+burn 1 ATP for this step
1st step of glycolysis continued
glycogen glucose turns into glucose 6 phosphate
3rd step of glycolysis
phosphorylate glucose again (requires phosphate from the hydrolysis of ATP and ADP)
3rd step of glycolysis continued
fructose 6 phosphate into fructose 1, 6 diphosphates (added phosphate to fructose carbon1)
-1 phosphate to the position of glucose
= phosphofructokinase (PFK)
-burn 1 ATP for this step
4th step of glycolysis
6 molecule broken up into 2, 3-carbon molecules
-Aldolase
pyruvate and lactate are
3 carbon molecule
step 6 of glycolysis
requires NAD+
add phosphate to the 1 position of phosphoglyceraldhyde = 1, dis phosphoglycerate
glyceraldehyde 3 phosphate
dehydrogenase
-results in NADH or FADH2
NADH is produced and it goes to the
ETC in mitochondria
7th step of glycolysis
is to de-phosphorylate 1,3 Diphosphoglycerate
-requires ADP
-phosphate from 1 position is transferred to ADP
-phosphoglycerate Kinase (PK)
step 10 of glycolysis
is to dephosphorylate PEP
-phosphate from PEP is transferred to ADP
-second ATP produced
substrates of glycolysis
- glucose or glucose 1 phosphate
- ATP
- ADP
- NAD+
products of glycolysis
- ATP
- ADP
- NADH
- pyruvate (lactate)
controlling glycolysis - rate-limiting enzymes
-PFK
-HK
-PK
controlling glycolysis - negative feedback
inhibited by ATP citrate (slow glycolysis down)
activated by ADP and insulin - speed glycolysis up
ATP producing enzymes end in
kinase
incomplete oxidation of glucose
end product =pryuvate and lactate
complete oxidation of glucose
end product = pyruvate to the mitochondria
then to Acetyl-CoA and into krebs cycle
redction reaction
gaining electrons (signified to us by gaining H+)
oxidation reaction
losing electrons. (signified by losing H+)
oil rig
o= ox
i= is
l= losing H
r-red
i=is
g=gaining H
