50. Biochemical Signalling in Exercise

Question 1

How does signal transduction work?

Answer 1

A certain signal e.g. hormone, nutrient

Binds to receptor on cell

Molecule activated e.g. transcription factor

This allows the organism to react to the stimulus recieved

Question 2

What chanegs may occur in repsonse to a signal

Answer 2

Protein synthesis

Protein breakdown

Transcription

Question 3

What changes occur in a cell after exercise?

Answer 3

Resistance training- Protein synthesis

Endurance training- Cell signalling

Question 4

Discuss how the signal transduction pathway grew throughout time with relation ot calcium

Answer 4

Bacteria- Calcium is bad and can precipitate when exposed to phosphate. Calcium pumps developed

Prokaryotes- Need some calcium so developed calcium channels to allow calcium back in

Eukaryotes- Developed calcium storing organelles and calcium binding proteins

Question 5

How is MTOR activated

Answer 5

Insulin can be one activator- shows that protein synthesis should occur

Insulin binds to insulin receptor

PKB is activated

PKB activates MTOR

Question 6

What occurs when MTOR is activated

Answer 6

More protein is produced from RNA pathways

Studies have shown without MTOR individuals cannto stimulate protein synthesis

Question 7

How is mitochondrial biogenesis induced (mitochondrial growth)

Answer 7

Increase in AMP (decreasing ATP stores, increased calcium) causes activation of transcription factor AMPK and therefore the production of PCGa1

This causes productions of proteins that indices mitochondrial protein induction leading toedurance adaptations e.g. increase in mitochondria

Question 8

What different components are involved in gene expression and transcription

Answer 8

Primer and pioneer trnascription factors

Signal responsive Transcription factor promotors

Signal responsive Transcription factor enhancer (loops, sometimes from other chromosomes)

Question 9

What dont i understand

Answer 9

The IGF-1 Study

Question 10

How does hypoxia signalling induce adaptation?

Answer 10

Mediated by HIF-1 which is contantly produced but typically broken down by oxygen

In hypoxia HIF-1 is translocated to the nceaus ad=nd binds to hypoxia response element

Question 11

What does HIF-1 induce

Answer 11

EPO

Apoptosis- IGF-2

Glucose metabolism- Metabolism

Protelysis

Angiogenesis- VEGF

Many, many more- see paper

Question 12

How is energy metabolism affected by HIF-1

Answer 12

Reduced or innaportiate repsonses to glycolysis and beta oxidation when HIF-1a is reduced

Question 13

What is the warburg study?

Answer 13

Measurement of lactate formation and glucose in tumour cells

Foudn out that glucose utilisation is through the roof however also found that lactate fermentation is the main form of energy production

Question 14

What tissue has constant lactate supply

Answer 14

Red blood cells

Question 15

What is the warburg effect shown by the warburg study

Answer 15

The TCA cycle is oversaturated and is unable to recycle the NADH the mode of energy production becomes anearobic glycolysis

Question 16

What is the hypothesis of how the warburg effect is propagated

Answer 16

Activation of AKT gene causes mitochondrial biogenesis

This creates increased reactive oxygen species, furhter damaging mitochondrial DNA forcing a shift towards glucolytic pathways

Question 17

How is the production of reactive oxygen species hypothesised to impact TCA

Answer 17

If reactive oxygen species are being produced via the TCA the cell has a pathway to deactivate pyruvate dehydrogeanse reducing aerobic glycolysis

Question 18

What happens to the remainign glucose that isnt used for aerobic glycolysis

Answer 18

Shifts towards nucleotide biosynthesis

This is required for genomic division

Question 19

How does the warburg effetc apply to exercise science

Answer 19

Stem cells also utilise this pathway in order to grow new cells