Metabolism Flashcards
what are three types of macronutrients
- carbohydrates
- lipids
- proteins
what are the sub-units of proteins
amino acids
when do proteins become a fuel source
when CHO and lipids are low
at rest, what is the main source of fuel?
- lipids- 60%
- chos 35%
- AA 5%
during exercise where does fuel mostly come from?
- CHOs 10-90%
-Lipids 10-90%
-AAs 5-10%
depends on type of exercise
how does CAP increase muscle force output?
- H-reflex induces overflow that excites target motor neurons
- remote voluntary contractions in other muscles may induce motor overflow that excites target neurons
what energy system would a wrestler rely on the most during a 3 min round of sustained high intensity?
glycolytic
which macro nutrient fuel source would using the glycolytic system rely on for energy production?
glucose (carbodydrates)
When a muscle produces maximal force at a fixed velocity, it is an _______
isokinetic contraction
which factors can act to limit or impede the immediate energy system function?
the total amount of creatine phosphate stored within a muscle
- crP combines with ADP to make ATP quickly
- it is the preferred way to get ATP in the immediate system
which compounds can be used to transport H+ and e- for use in aerobic metabolic pathways?
NADH + H+
FAD
which triggers from heavy use of the immediate energy system can stimulate enhanced glycolytic activity?
- skeletal muscle contraction
- increased AMP concentrations within the muscle
which enzymes serve to regulate glycolysis
- hexokinase
- phophofructokinase
during glycolysis, fructose-6phosphate gets directly converted to
gructose- 1,6 phostate
what is the order of glycolysis
- glucose (hexokinase)
- glucose 6 phosphate
- fructose 6 phosphate (phosphofructokinase)
- fuctose 1,6 phosphate
- dihydroxyacetone phosphate
- glyceraldegyde 3 phosphate
- 1,3 bisphophoglycerate
- 3 phosphoglycerate
- 2 phosphoglycerate
- phosphophenoly pyruvate
- PYRUVATE
describe the effect that creatine supplementation has on immediate energy system function
creatine supplementation can increase the duration of the immediate energy system by 2-3 seconds. The muscle sarcoplasm stores create that combines with ADP to make ATP. If creatine supplementation increases the amount of Cr available, more ATP can be made. It can increase intensity or duration of exercise.
which energy system is most dominant for a runner during a marathon?
mitochondrial respiration (infinite duration)
If a well trained runner walked an entire marathon at a light intensity, what could source would he/she rely on for energy production?
Lipids/Fats. until RER .9
what is the NET ATP production from a 22-carbon free fatty acid that is fully metabolized via mitochonrial respiration
-180 ATP
- -2 ATP to start (22/2 -1=10)
-B oxidation- 10 NADH+H+ (30ATP) 10 FADH2 (20ATP) 11 acetyl COA
-krebs- 11 acetyl COA (11ATP)–> 11 FADH2 (22ATP) 33 NADH+H+ (99ATP)
TOTAL- 180!!!!!
Which anatomical features of Type 1 skeletal muscle allow them to use mitochondrial respiration well?
- lots of myoglobin
- lots of mitochondria
- lots of blood capillaries
which enzymes regulate B-oxidation?
B-ketothiolase
which enzymes regulate the krebs cycle?
isocitrate dehydrogenase
during ETC/OP how many ATP are produced from 10 NADH + H+?
30.
3 ATP per NADH + H+
how many ATP are produced from each FAD?
2 ATP per FAD
what are the possible fate for pyruvate following glycolysis?
- it gets shuttled into the mitochondria and converted to Acetyl-CoA
- it gets converted to lactate and H+ in the muscle sarcoplasm
what is the difference in NET ATP production from glycolysis between 3 molecules of glucose compared to 3 molecules of glucose-6-phosphate?
3 ATP
-glucose-6-phosphate requires only 1 molecule of ATP to start compared to 2 from glucose.
During the Krebs cycle, isocitrate gets directly converted to____?
alpha-ketogluterate
draw the krebs cycle.
acetyl Co A, citrate, cis-aceonitate, isocitrate (isocitrate dehydrogenase), alpha ketogluterate, succinly co A, succinate, fumarate, malate, oxyloacetate
what is one benefit of mobilizing lipids as a fuel source compared to carbohydrates?
- you will burn more fat
- longer duration of exercise
what is a disadvantage of mobilizing lipids as a fuel source compared to carbohydrates?
-decrease in exercise intenisty
An RER of <.8- should indicate a reliance on which fuel source?
Lipids
What is the definition of VO2 max
the maximal ability to consume oxygen to produce ATP
which 4 criteria can validate a successful VO2 max test?
- plateau near end of test
- post LA of >8 mmol/dl
- RER >1.15 at the end of the test
- heat rate within 5 bpm of expected age
what type of athletes benefit from high Vo2 max?
endurance. soccer. runners…
1 mol of leucine was deaminated to produce one acetyl co A. what is total ATP produced in mitochondrial respiration?
12 ATP
- acetyl CoA goes to Krebs cycle
- krebs produces 3 NADH+H+ and one FAD2 and One ATP per acetyl coA
- ETP/OP makes 9 ATP from NAD and 2 from Fad + the one from Krebs
which hormones can be used to mobilize glucose or glycogen for fuel during exercise?
insulin
glucagon
epinephrine
which hormones promote synthesis (storage) of glucose or glycogen?
glucagon
cortisol
growth hormone
How could an unfit individual use the RER and HR data from the lactate threshold or VO2 max tsests facilitate training for improved fat mobilization and aerobic metabolism?
- by finding their range of HR in comparison to VO2 max, they could keep the HR low enough to continue use of mitochondrial respiration (low intensity)
- or they could make sure that their RER is ind .8 to continually burn fat
How could HR data during the lactate threshold and VO2 max be used by an endurance athlete?
they can raise HR to around VO2 max in intervals, to raise their “ceiling” and raise the % of the VO2 max at lactate threshold.
when does lactate threshold occur?
when blood lactate spikes and reaches around 4mmol/dl
-when you switch from mitochondrial respiration to others
why is power output at VO2 max so high?
it relies on all 3 systems. it is tied to the other two (immediate and glycolytic) so it has limitations
at what RER or Ve level is Lactate threshold?
around 1.00 RER or when Ve has a big increase
What does a high VO2 max have on endurance?
increases insurance potential.
-genetic and trainable
how is ventilatory threshold used to determine LA?
the “talk test” will determine how much Co2 is leaving the body during exercise. the more H+ ions that accumulate in the blood, the more CO2 will be breathed out. a higher LA will make talking harder.
what is the y axis on the time vs ___ graph?
ATP rate or exercise intensity.
what is Anabolism?
building up of large molecules from smaller molecules
what is catabolism
degrading large molecules into smaller ones. releases energy
why is creatine phosphate not as cool as ATP?
it gives off energy well, but doesn’t accept phosphates as easily
how are metabolic pathways controlled?
- enzyme availability
- energy needs of cells
- temperature and pH
what are the ox/redox compound that transport H+ and E- in metabolic pathways?
-NAD+
-NADH
-NADH + H+
FAD
FADH2
which enzymes regulate the immediate system?
- creatine kinase
- myokinase
- myosin ATPase
what are the limiting factors of immediate system?
-amount Creatine phosphate available and ATP
once ATP and CrP stores are exhausted, how is ATP synthesized?
-glycolytic system
where does glycolysis occur?
within the muscle sarcoplasm
which two systems occur within the muscle sarcoplasm?
-immediate and glycolytic
which system occurs in the muscle mitochondria?
-mitochondrial respiration
how does the composition of type 2 muscle fibers benefit anaerobic respiration?
type 2 fibers have less mitochondria, so there is more storage for CrP
what product comes from glycogenolysis?
break down glycogen to glucose 6 phosphate
which enzyme is used in glycogenolysis?
phosphorylase
why is glycogenolysis important?
it preps glucose for glycolysis and only requires 1 molecule of ATP
at what point in the glycolytic system does everything happen twice?
dihydroxyacetone phostphate is split into 2 glyceraldehyde 3 phosphates
what are the products of glycolysis?
per glucose:
- 2 net ATP (4 but need 2 to start it)
- 2 NADH + H+
- 2 Pyruvate (go to acetyl co A (2 NADH+ H+) then to Krebs cycle)
when is pyruvate shuttled into the mitochondria? and then what happens?
when glycolysis is slow. in lighter intensity exercises.
- this activates pyruvate deydrogenase to go to acetyl CoA to krebs cycle. (links mitochondrial and glycolytic)
what product come from converting pyruvate to acetyl CoA
2 Nadh + h+
2 acetly-CoA
2 CO2
What happens to pyruvate during high intensity exercise?
- mitochondria can’t accept all of the pyruvate so it is converted to Lactate by NADH = H+.
why are hydrogen ions bad?
the hydrogen ions are acidic and stimulate free nerve endings in muscle fibers (muscular burn) and denatures proteins and slows their ability to function. they shut down anaerobic metabolic pathways b/c of acidic enzymes don’t work well
why is lactate considered a friend in exercise performance?
it can be shuttle into the mitochondria within the same muscle fiber, or out to adjacent fibers, other muscles or liver to be converted to new glucose
what would be the products of 3 molecules of glucose from glycolysis
6 ATP
6 NADH + H+
6 Pyruvate
-6 NADH + H+ in converting pyruvate to acetyl coA
what are 3 mitochondrial pathways?
-krebs
ETC
OP
what enzymes regulate Krebs?
dehydrogenases (mostly isocitrate dehydrogenase
what are products of Krebs?
based on 2 acetyl coA from glycolysis
- 2 ATP
- 2 FADH
- 6 NADH + H+
where is all of the energy harnessed in NADH H and FADH2?
Electron transport chain/ oxidative phosphorylation
explain / draw electron transport / oxidative phosphorylation
- cytochromes in inner membrane of mitochondria accept protons from nadh and fadh2
- e- are stripped from H+ and passed down the chain
- protons are pumped out of matrix, making a gradient of potential energy
- e- are trapped by O2 and combine with H+ to make H20 (2H+ + ½ O2 + e- = H20)
- protons that were pumped out into the inter-membrane space re-enter in OP.
- the proton re-entering releases kinetic energy and puts a Pi on ADP to make ATP
What enzyme regulates ETC/OP
ATP synthase
what are the products of ETC/OP
glycolysis- 2 Nadh+ = 6 ATP
pyruvate conversion to acetyl coA- 2 NADH+ = 6ATP
Krebs - 2 FADH2 = 4 ATP
Krebs - 6 NADH+ = 18 ATP
what is the total ATP through mitochondrial respiration from one molecule of glucose?
- 38 ATP
- 2 glycolysis
- 2 Krebs
- 34 ETC/OP
how much ATP is made if glucose comes from glycogenolysis?
39 ATP
during lypolysis, triglycerides are degraded to free fatty acids, where do they go?
-released from adipocytes to muscle fiver
What are FFA converted to ?
fatty acyl CoA
what are the products of Beta Oxidation?
1 acetly coA (goes to krebs)
1 NADH+H+
1 FADH2
what determines the number of cycles through Boxidation?
the number of carbons in FA-CoA (#/2 -1)
how much energy is made by a 20 carbon fatty acyl co A?
intial activation takes 2 ATP - 9 FADH2 -9 NADH+H+ -10 acetyl-coA to krebs -10 FAD -30 NADH -10ATP TOTAL= 163 ATP
what effects does lipid metabolism have on weight loss?
fat burn in exercises
- low intensity –> wait for energy stores = burn lots of fat
- high intensity is ok. gives different hormones to increase resting metabolism
when is Amino acid metabolism used?
-excess supply for protein synthesis. CHO-deprived states
how is AA metabolism used?
- amine group removed by deamination and urea cycle
- ATP yeild depends on where enters in metabolic pathway
how much ATP would come if an AA entered at alpha Ketogluterate
you would miss out on one NADH, so -3 ATP.
2 NADH, 1 FADH, 1 ATP from krebs
what are the differences in hormones than neurotransmitters?
hormones produce larger changes and longer acting changes
what are the roles of insulin?
- stimulate liver, muscle and fat to clear glucose from blood to mobilize for fuel
- stimulates protein synthesis
- lipogenesis
what are roles of glucagon
- stimulate glygenolysis (make G6P) to mobilize glucose for rule
- lipolysis in adipocytes to mobilize FFA
- deamination to mobilize AAs
- when CHO low- stimulates glugoneogenesis for more glucose
what are the roles of epinephrine?
- stimulate glyconeogenosis to mobilize glucose for fuel
- stimulates lipolysis in adiopcytes to mobilize FFA
what are roles of norepiniephrine
-stimulate lypolysis in adipoctyes and muscles to mobilize FFA
how do insulin and glucagon work together during exercise?
glucagon increases to free G6P and insulin decreases but works better b/c muscles are more sensitive to it
what are roles of cortisol?
- stimulates lyoplysis to mobilize FFA
- stim. gluconeogenesis from ketones
why wouldn’t you want to increase cortisol when a low carb die at?
unless you have high protein intake, cortisol stimulates deamination to mobilize AA
what are roles of growth hormones?
- stimulate production of IGF-1
- lypolysis in adiipocytes to mobilize FFA
- stimulates gluconeogenis
what are the roles the insulin-like growth factor-1
facilitates AA uptake and protein synthesis in bone and muscle
which hormones are used to mobilize FFA by lipolysis?
- glucagon
- epinephrine
- norepiniephrine
- cortisol
- growth hormone
which hormones use deamination to mobilize AA?
-glucagon
which hormones stimulate or facilitate protein syntesis
IGF-1
insulin
which hormones stimulate lipogenesis?
insulin
which hormones stimulate gluconeogenesis
growth hormone
WHAT INFLUENCES HORMONAL RESPONSES
intensity and duration of exercise
- eating = fuel storage
- working out = fuel mobilization
