Lec 4 (Mito)

Question 1

What does VO2 max measure?

What is it influenced by?

What does it evaluate?

Answer 1

an individuals maximum rate of oxygen consumption.
(in test u max out oxi. phosphorylation)

3 Influences = O2 DELIVERY to CV system and O2 EXTRACTION from blood into skeletal muscle/tissue

The RATE of energy production and oxygen use once inside the muscle cell.

Question 2

What is the best biomarker of (overall) health and premature death?

Answer 2

A VO2max test

Question 3

How do you calculate RER?

Answer 3

Divide CO2 by VO2

.7 = Fat; 1.0 = CHO aka 65% VO2 max or greater

Question 4

What does an RER above 1.0 tell us?

Answer 4

that it is no longer fats or CHO being used, we now have an increased contribution of anaerobic metabolism

Question 5

Where does the Kreb Cycle Occur?

Answer 5

In the matrix of the mitochondria.

Question 6

Bc the outer membrane of the mitochondria is most permeable, what does to it allow to take place?

Answer 6

The passage of protons and metabolites such as ATP, ADP and other nutrient molecules.

Question 7

Where is the site of the electron transport chain?

Answer 7

Along the cristae (where oxidative phos. occurs(; the inner membrane of the mitochrondia.

What is the intermembrane space used for?

For the exchange and transport of enzymes. It also HOLDs the protons hat are being accumulated in prep for ATP production.

Question 8

What enzyme transports lacate into teh mitochondria?

Answer 8

MCT1

Question 9

What is LDH

Answer 9

Lactate will be oxidized into pyruvate into the mitochondria.

Question 10

What does the bicarbonate buffering system do?

Answer 10

It produces non aerobic CO2 (an extra source) that helps us maintain pH levels in the blood as a result of increased rate of (ATP) hydrolysis..

Extra H can make blood acidic and this system “sucks” any excess up by latching to CO2 (CO2+H =) Carbonc acid gets into blood, travels to lungs and is expired as CO2

Question 11

What drives RER above 1?

Answer 11

The biocarbonate buffering system and teh extra source of CO2 it provides.

Question 12

Name the various parts of the mitochondria and state there purpose.

Answer 12

Outer Membrane - most permeable, allows protons and metabolites to pass

Inter membrane - transporting membrane (lil deeper) requires enzymes/proteins for transportation and exchange.

Inner membrane - responsible for metabolite transportation (e.g. fats thru carnintine transferase) & impermeable to protons/e- (3a); ALSO cite of cristae membrane *including folds and actual cristae) + its the cite of ox. phos. (i.e. ETC)

The Matrix - cite of Kreb cycle and location of mDNA and 1/2 of the mitochondrial proteins

Question 13

Pyruvate dehyrogenase is the conversion of pyruvate to acetyl CoA, but what else occurs during this process?

Answer 13

NAD+ is reduced to NADH

Question 14

Chemoosimos is described as what?

Answer 14

The flow of H ions from the intermembrane space (thru ATP synthase) back into the matrix for the creation of ATP thru the phorphorlation of ADP to ATP.

Question 15

What hydrolyzes (breaks down) chylomicrons and trigecerides into FFA?

Answer 15

Lipoprotein lipase (FFA)

Question 16

What hydrolyzes (breaks down) chylomicrons and trigecerides into FFA?

Answer 16

Lipoprotein lipase LPL (FFA)

Question 17

How do we regulate blood glucose levels?

Answer 17

via insulin signalling

Question 18

What causes teh converion of pyruvate into acetyl coA?

Answer 18

Pyruvate dehydrogenase.

Question 19

The inflammation of lipid oversupply causes insulin resistance and inflammation messes with the insulin signalling pathway. True or False?

Answer 19

True!

Question 20

The inflammation of lipid oversupply causes insulin resistance and inflammation messes with the insulin signalling pathway. True or False?

Answer 20

True!

Question 21

What is the role of HSL in lipolysis?

Answer 21

To help with the mobilization of FFA from adipocytes.

Question 22

What is HSL stimulated by?

What is it inhibited by?

Answer 22

Hormones, hence the name: Epi., norepi. & GH.

Insulin

Question 23

Once a triglyceride is broken down & the FFA are mobilized, what happens (meaning where do they go?)

Answer 23

They are carried into circulation by way of albumin.

*If TG is begin actived upon by HSL in skeletal muscle, the FFA will enter mito. for ox.phosphor. / ATP production

Question 24

What carries fat in blood circulation?

Answer 24

Albumin

Question 25

What are teh different fatty acid transporters?

Answer 25

• Plasma membrane Fatty acid binding protein (FABP) aka S-FABP
• Fatty Acid Transpoter Protein (FATP)
• Fat acid transcolase (FAT/CD36)
• S-FABP
• FABPc

Question 26

What is the name of the lipase that breaks down fat in skeletal muscle?

Answer 26

Type L-HSL

Question 27

In Beta Oxidation, why is fatty ACYL-CoA degraded? And what happens with each cycle?

Answer 27

Acyl-CoA is degraded to become Acetyl-CoA in preparation for kreb cycle entrance.

For each Beta oxidation cycle, 2 carbons are removed and 1 NADH & 1 FADH are produced in prep of ETC.

Question 28

Where does protein metabolism take place and why is it rarely used for e. production?

Answer 28

It takes place in the liver (via amino acids) and its rarely used for e. bc it its energetically costly, no place t store it and slow to process so inefficent (Nitrogen has to be removed) + protein/amino acids are our builidng matter for muscle syntheis

Question 29

A lack of CHO (glucose/glycogen) forces oxaloacetate into gluconegensis and consequently turns Acetyl CoA into ketnone bodies. What may cause this and what is the negative implictaion of this?

Answer 29

CHO restriction or “depletion” due exercise/diet.

If no oxaloacetate, we have no full kreb cycle. Ketones will be used for fuel via ATP production