Genetics - Exercise Flashcards
What are the key aspects of exercise which effect the genetic responses?
Intensity Duration Frequency Type of exercise Period of the day
Describe the change in working capacity during and after exercise.
Everyone has their own individual working capacity level.
During exercise the working capacity decreases.
After exercise the body tries to recover homeostasis and the working capacity increases. Around 3-4days after exercise there will be period of supercompensation where there is a higher working capacity than before the stimulus. During this period the body is more prepared for the stimulus and can cope better with it.
Repetition and consistency of exercise causes the persons working capacity to increase, however if the type and intensity of exercise is the same it reaches a point where it cannot increase any more. To increase it, the intensity of exercise needs to be increased.
How does the body try to recover from exercise
Increasing protein synthesis in muscle cells to increase muscle production, increase of antioxidants to reduce free radical damage/ oxidative stress, increase synthesis of glucose transporters so more glucose is absorbed into the cells.
What are the ways energy is produced?
And how much ATP is produced?
ATP stores - quick release
Anaerobic respiration - 2-3ATP
Aerobic respiration - 34-36 ATP
Lipolysis - 130 ATP
Describe lipolysis
Fatty acids are broken down and turned into energy.
Fatty acids are oxidised in the mitochondria where up to 130 ATP are produced from 1 fatty acid that is oxidised. Oxygen is a limiting factor and the capacity to oxidise fat into ATP is increased with repeated exercise.
Explain the relationship between mitochondrial DNA and oxidative damamge
During the electron transport chain in respiration electrons are required to move H+ along the channels. During this some electrons leak out into the intramembrane space where they combine with oxygen to from superoxide radical which is very unstable and can cause cellular damage.
The superoxide radical is oxidised to hydrogen peroxide, H2O2, a less but still damaging free radical.
PPX, GPX and catalase oxidise H2O2 to H2O and O2, which are stable and cause no damage to the body.
GPX, PPX and catalase are endogenous proteins otherwise known as antioxidant which are essential for removing free radical molecules than can cause damage to the body.
What happens if the endogenous proteins are not present?
H2O2, Hydrogen peroxide remains in the body and can damage to the DNA, if there for a long time it can cause mutation, and some diseases such as cancer
How does exercise increase the number of antioxidants in the body?
Consistent exercise can cause an up-regulation of transcription factors which bind to genes and cause translation.
This can occur on genes which code for endogenous proteins, where the up-regulation of transcription factors causes more antioxidant proteins to be produced.
What is the relationship between exercise and antioxidants
More exercise –> More endogenous proteins
BUT at the same time
More exercise –> More free radicals
This means a balance is created and the fact that more free radicals are produced is not a problem as there are the antioxidants that are also being produced to oxidise them into molecules which are not harmful
How can exercise lead to more ATP production? (over time)
With increased exercise there is an increased up-regulation of transcription factors which means that there is more synthesis of PCC1a which is used to increase the amount of mitochondrial respiratory proteins which in turn make more mitochondria where more lipolysis can occur resulting in more ATP being made.
How does exercise have an effect on glucose absorption?
With increased exercise there is an increased level of myokines which can then increase the amount of glucose transporters so more glucose can be absorbed from the bloodstream into the cells, to be used for a variety of processes, e.g metabolism.
This is a way of preventing insulin resistance.
How can vitamin C have an effect on free radicals?
Vitamin C/ ascorbic acid is an antioxidant that can be obtained from diet.
It oxidises hydrogen peroxide which results in the formation of water and ascorbate.
Having too much vitamin C can have the opposite effect as it can then combine with iron to form ascorbate radical which is a free radical.
There is enough vitamin C is the daily diet/ recommended guidelines to help combat oxidative stress and free radicals
What is methylation?
How does it relate to exercise and genetics?
Methylation is the addition of a methyl group, found especially in cytosine. It binds to the promotor region and means that transcription factors cannot bind therefore inhibiting the process of transcription and overall gene expression and protein synthesis.
It does occur naturally in ageing, however by increase exercise levels there is a proven decrease in methylation.
By exercising consistently there is a decrease in methylation which means more PGC1a can be synthesised to produce more mitochondria to help the persons capacity for ATP production.
Exercise causes the hypo-methylation of PGC1a after exercise to allow that increase in mitochondria to occur.
This in turn increases fatty acid synthesis, TCA cycle, oxidative stress defence, mitochondrial biogenesis.
It can also create hypermethylation of adipose tissues meaning there is a decrease in production of fatty acids stores allowing more fatty acids to be used for energy.
However it still relies on intensity and duration of exercise.
Describe telomeres and their relationship with exercise
Telomeres are important to control cell division and get shorter with repeated division. When it gets to a point where it cannot divide anymore the cycle of the cell is over.
Active people have longer telomeres meaning the life cycle of the cell is longer.
Telomeres can also decrease in length with age, and in women who are highly stressed
