Kinesiology 2230A/B Lecture Notes - Lecture 7: Mitochondrion, Acetyl-Coa, Phosphofructokinase
19 Oct 2018
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Lecture 7:
- altitude change in -3/1000 ft
- hypothermia clothing
- as you get colder your body is deciding we are going to sacrifice periphery and keep your
core warm
- have vasoconstriction in the body, reducing the diameter, less blood flow so you can keep
blood warmer and not sending it out to get cold
- less atmosphere above you so the sun is stronger as you go up in altitude
review:
- epinephrine and norepinephrine from adrenal gland
- break down fats- the fatty acids and glycerol are broken
- fatty acids and glycerol to blood stream
- mobilized fat from periphery
- transport fatty acid so it arrives at working muscle
- transported through carcolema
- fatty acid binding proteins
- transport across cytosol where glycolysis happens
- have to get through outer mitochondrial membrane
- added CoA to fatty acid requiring a little every, and added acetyl group= fatty AcytelCoA
- this compound wont pass inter-mitochondrial membrane
control of metabolism:
- tremendous availability of fats
- can live about a month without eating because of fats
control:
- if producing fatty acids, now have fatty acids giving Acetyl CoA which will go to citrate
- as glucose and glycogen giving us citrate form glycolytic pathway
- citrate will inhibit PFK in glycolysis
- if we inhibit PFK, reaction of PFK slows, as we move upstream, glucose 6 phosphate will
accumulate (everything gets backed up) and this will inhibit the breakdown of glucose in the
presence of hexokynase
- glycogen used at fuel and can use fatty acid to give us energy that we require
- limited carb store
- cascade that will reduce glycolytic flux- speed at which carbs are being broken down in
glycolytic pathway
- glycolytic flux slower at beginning and end of pathway
- always going to be a little bit of carbs being used
- when glucose or glycogen are depleted, going to be fatigued. cant run on just fats
- need minimal flux through glycolysis to maintain ATP production
- get most energy from fats
- once lactate accumulates, inhibits released fat from the periphery
- will use a lot more carbs for this energy
burning fats:
- oxidation of fats in kcals/hour
- have 20% (as slow as you can job/brisk walk)
- 50% of VO2max getting close to burning 350 kcal directly from fats
- as you continue to increase intensity, contribution from fats is reduced because need energy
faster so switch to carbs
Review:
Fatty Acid synthesis from CHO
• Blood glucose to fat
• From CHO we can make fats
• Goes down glycolysis, get acetyl CoA and then another and so on
• If it’s a resting situation, the 7 acetyl CoA are sequentially bound together in the
presence of fatty acid synthase to make a fatty acid
• Able to store energy for later and hopefully used later
• This all happens in the liver and adipose tissue – glycolytic pathways, enzymes etc.
Ketones
• Carbonyl group (a carbon-oxygen double bond)
• Produced by the liver during periods of low CHP from free fatty acids
• Used as substrate-converted back into Acetyl-CoA to enter Kreb’s cycle for energy
• They are formed from fatty acids when there’s very little CHO available
• Brain lives on glucose and loves CHO
• Can form ketones from CHO and from these ketones can form acetyl CoA and in
particular that can be used by the brain as substrate
• If haven’t eaten for a few hours, some people get grumpy, CHO low and brain needs
glucose – tells us we need to eat
• After several weeks of starvation ketone bodies become major fuel of brain (brain
derives 60-75% of energy from ketone bodies under conditions of prolonged
starvation)
FULL NOTES:
Today- Lecture 7
• Altitude changes in -3/1000 ft
• Hypothermia clothing
• As you get colder your body is deciding we are going to sacrifice periphery and keep
your core warm
• Have vasoconstriction in the body, reducing the diameter, less blood flow so you can
keep blood warmer and not sending it out to get cold
Document Summary
As you get colder your body is deciding we are going to sacrifice periphery and keep your core warm. Have vasoconstriction in the body, reducing the diameter, less blood flow so you can keep blood warmer and not sending it out to get cold. Less atmosphere above you so the sun is stronger as you go up in altitude review: Break down fats- the fatty acids and glycerol are broken. Fatty acids and glycerol to blood stream. Transport fatty acid so it arrives at working muscle. Have to get through outer mitochondrial membrane. Added coa to fatty acid requiring a little every, and added acetyl group= fatty acytelcoa. This compound wont pass inter-mitochondrial membrane control of metabolism: Can live about a month without eating because of fats control: If producing fatty acids, now have fatty acids giving acetyl coa which will go to citrate. As glucose and glycogen giving us citrate form glycolytic pathway.
