Kin 3070 Exam 2 Flashcards
What percent of energy is release as heat in the body and what percent is used for work?
About 40% of total energy is used to generate ATP. About 60% is released as heat.
ATP is the primary fuel source for what?
The body
Human bodies are what?
Human bodies are inefficient machines.
1 kilocalorie is that amount of heat needed to raise how much water?
1 kilocalorie is that amount of heat needed to raise 1L of water. 1-15 C
What are the calories associated with the three macronutrients?
Carbs have 4.1 calories, Protein has 4.3 calories, and fat has 9.4 calories.
What macronutrient is used primarily for exercise and why?
Carbs. Carbs are more accessible to muscles.
Bioenergetics describes the process of what?
Bioenergetics describes the process of converting substrates into energy, like fats carbs and proteins.
The difference between protein and the other nutrients is what?
The difference between protein and the other nutrients is that protein has a nitrogen attached to it.
What fuel sources do we use at rest, during exercise, and during long distance exercise?
At rest we are at about 50% carb usage and 50% fat usage. During exercise it’s mostly carbs. During long endurance bouts its carbs and a little bit of fat.
Describe fat stores in the body
Fat stores 70,000 calories and 7800g in the subcutaneous and visceral fat. It stores 1500 calories and 161g in the intramuscular.
Describe Carb stores in the body
Carbs are stored with 110g in the liver, 500g in the muscle, and 15g in the blood. There are 450 calories in the liver, 2000 in the muscle glycogen, and 62 calories in the blood.
Where do anaerobic and aerobic energy systems take place in a cell?
Anaerobic energy systems take place in the sarcoplasm, aerobic energy systems happen in the mitochondria.
Myokinase is?
Myokinase is an enzyme in the sarcoplasm, it takes 2 ADP and makes it into 1 ATP and 1 AMP. It is like an emergency generator during the phosphagen system to make some quick ATP.
What does lactate do for us?
Lactate is an important fuel source during exercise. Lactate produced with fast glycolysis can be taken up by the mitochondria of the same muscle fiber and can be oxidized to make more ATP. It can be shuttled to other muscle cells. Lactate can also be regulated back to the liver where it can be reconverted into glucose (gluconeogenesis) also known as the Cori Cycle.
For every NADH that is brought to the inner mitochondrial membrane makes about how much ATP
2.5 ATP
What is oxygens role is ATP production
Oxygen collects electrons at the end of the oxidative ATP production process.
What is lipolysis?
Lipolysis is taking a triglyceride and breaking it apart so it can go under beta oxidation in the mitochondria and is converted into Acetyl CoA.
Our oxidative capacity is determined by?
Our oxidative capacity is determined by our ability to uptake oxygen through our lungs, O2 is not stored very much at all in the body.
Define direct and indirect calorimetry
-Direct calorimetry is the exact amount of heat you are producing to calculate energy expenditure.
-Indirect calorimetry is an indirect way to measure heat production. This can calculate energy expenditure from the respiratory exchange ratio. (RER)
The concentrations of air consists of?
79.03% N2, 20.93% O2 and .03% Co2
At rest RER is at?
.78-.80
What is glucose made up of? Pyruvate? Lactate?
6 carbon molecules. Lactate and Pyruvate are 3 carbon molecules.
What is the Cori Cycle?
This is when lactate is moved to the liver and turned back into glucose, (gluconeogenesis).
Explain all 3 energy systems, their inputs, outputs and regulators.
The Phosphagen system (PCR) is stimulated when ADP goes up and ATP goes down, when ADP goes up it stimulates Creatine Kinase which separates phosphocreatine into 1 creatine and 1 phosphate. The phosphate can then bond with ADP to make ATP so it can be used quickly. So the inputs are phosphocreatine, the rate limiting enzyme is the creatine kinase, and the outputs are ATP, Creatine, and a Phosphate.
The glycolytic energy system starts with a glucose of glycogen molecule. Initially hexokinase adds a phosphate to glucose to start glycolysis this costs 1 ATP, glycogen does not need this. When ADP goes up this stimulates phosphofructokinase which tells glucose to break apart into 2 pyruvates. NADH then gives pyruvate a Hydrogen which turns it into lactate. NADH is now NAD+ which can now be reused in glycolysis to make more ATP. So the inputs are glucose and glycogen, the outputs are pyruvate, lactate, and NAD+, and the regulators are hexokinase and phosphofructokinase.
For the oxidative system, at the end of glycolysis when 2 pyruvate molecules are made, they then donate a carbon to an oxygen making Co2 which is then breathed out. When pyruvate turns into Acetyl CoA it also turns NAD+ into NADH. After pyruvate gives a carbon molecule it is now Acetyl CoA. Acetyl CoA then goes into the Krebs Cycle. The Krebs cycle then turns Acetyl CoA into citric acid which is a 6 carbon molecule. The Krebs cycle gets rid of two carbon molecules and The Krebs Cycles turns NAD+ into NADH 3 times. The Krebs cycle also turns 1 FAD+ into FADH. So in total we get 4 NADH and 2 FADH after two cycles. So including the two ATP we get from glycolysis and the Krebs cycle we now have 4 total ATP which then undergoes Oxidative phosphorylation.
Net gain of 2 ATP (substrate-level phosphorylation)
2 NADH (which yield about 5 ATP if shuttled efficiently into the mitochondria)
Pyruvate to Acetyl-CoA Conversion (Link Reaction):
2 NADH produced (about 5 ATP total)
Krebs Cycle (per glucose, 2 turns):
2 ATP (substrate-level phosphorylation)
6 NADH (about 15 ATP total)
2 FADH₂ (about 3 ATP total)
=32 ATP
The regulators are pyruvate dehydrogenase which regulates pyruvate turning into Acetyl CoA, Isocitrate Dehydrogenase which regulates the Krebs Cycle, and Cytochrome Oxidase which controls the electron transport chain.
