October, 2, 2023 Flashcards
what is DNA transcription
makes RNA
DNA → RNA
what is DNA translation
makes protein
RNA → protein
how do adaptations to exercise take place, leading to an altered phenotype. Explain what happens within the nucleus
When an individual engages in regular exercise, it can lead to changes in gene expression. The nucleus of a cell is where the genetic information in DNA is transcribed into mRNA, which serves as a template for protein synthesis.
Key players in the process of transcription include RNA polymerase and transcription factors. RNA polymerase is an enzyme responsible for transcribing DNA into RNA, specifically mRNA.
Transcription factors are proteins that regulate gene expression.
Regular exercise can trigger a variety of physiological responses, such as increased muscle strength, endurance, and metabolic efficiency. These adaptations are often the result of changes in gene expression within cells.
what are the signals that will activate more mitochondrial synthesis
Calcium: calcium is released everytime you exercise
AMP
ROS: reactive oxygen species
(ex: calcium binds to a kinase, which activates it, kinase goes to nucleus and phosphorylates a transcription factor, transcription factor binds to DNA, it activates RNA polymerase, leads to more transcription)
what is a common theme between the three signals that activate more mitochondrial synthesis
all activate a kinase enzyme
a kinase phosphorylates something. In other words its going to add a phosphate group to a protein.
And sometimes that will lead to either the activation or inhibition of a protein
phosphorylation of transcription factor leads to …..
activation of transcription
how does the conversion of ADP to AMP occur
the higher the exercise intensity the more AMP you can make
what two nutrients do you always burn/oxidize at the same time
carbohydrates and fats
CD36
transport fatty acid into muscle cell
page 50 is kind of a review of what we learned so far
intramuscular sources of energy exist as….(refer page 50)
glycogen and triglyceride
extramuscular sources of energy exist as….
fat: in adipose tissue
Carbs: in liver
What is RQ
Respiratory Quotient
Volume CO2/Volume O2
RQ = 1 (or around 1) means?
metabolizing carbs
RQ = 0.7 (or around 0.7 ) means?
metabolizing fats
The breakdown of fatty acids yields more CO2 relative to O2 than carbohydrates. This results in an RQ less than 1.0.
An RQ of 0.7 is commonly associated with the complete oxidation of long-chain fatty acids. When fats are metabolized in a process called beta-oxidation, they produce more CO2 and fewer water molecules compared to carbohydrates. The RQ of 0.7 reflects the increased production of CO2 and the decreased consumption of O2 during fat metabolism. This means that for every 7 molecules of CO2 produced, only 10 molecules of O2 are consumed, leading to an RQ of 0.7 (7/10).
What does RQ values tell us:
what substrate we are using for energy
how many Kcals we are burning per LO2 consumed
what does it mean when the RQ >1 in regards to Respiratory exchange ratio (RER) and buffering of lactic acid
When the Respiratory Quotient (RQ) is greater than 1, it typically suggests that the ratio of carbon dioxide produced (VCO2) to oxygen consumed (VO2) during metabolic processes is higher than expected.
Let’s explore what it means when the RQ is greater than 1 and its relationship to lactic acid buffering:
Lactic Acid Production: An RQ greater than 1 is often seen in situations where lactic acid (lactate) is produced as a metabolic byproduct. This is especially common during intense or anaerobic exercise when the body’s demand for energy exceeds the supply of oxygen, and glucose is partially metabolized through anaerobic glycolysis, leading to the accumulation of lactic acid.
Buffering Lactic Acid: When lactic acid accumulates in the muscles and bloodstream, the body relies on various buffering systems to maintain pH balance and prevent a drop in blood pH (acidosis). These buffering systems include the bicarbonate buffering system and other chemical buffers. By producing more CO2, the body can increase the availability of bicarbonate ions (HCO3-) to help neutralize the excess protons (H+) produced by lactic acid.
In summary, an RQ greater than 1 is indicative of metabolic processes in which excess carbon dioxide is produced, often due to the production of lactic acid during anaerobic conditions. This is a sign that the body is working to buffer the lactic acid and restore pH balance. Once oxygen becomes available and the body transitions back to aerobic metabolism, the RQ will return to more typical values.
How long does it take to burn 5 kcals at rest, when you are on a high carbohydrate diet, assuming that resting VO2 is 0.25 LO2/min
4 min
To determine how long it takes to burn 5 kilocalories (kcal) at rest on a high carbohydrate diet with a resting VO2 (oxygen consumption) of 0.25 liters of oxygen per minute (LO2/min), you can use the following calculations:
Convert kcal to LO2: The energy expenditure of 1 liter of oxygen is approximately 4.825 kcal. This is a conversion factor that allows us to relate the energy expenditure to the amount of oxygen consumed.
5 kcal × (1 LO2 / 4.825 kcal) ≈ 1.038 LO2
Calculate Time: Now that we know the energy expenditure in terms of LO2, you can calculate the time it takes to burn 1.038 LO2 at a resting VO2 of 0.25 LO2/min:
Time (minutes) = Energy Expenditure (LO2) / Resting VO2 (LO2/min)
Time = 1.038 LO2 / 0.25 LO2/min ≈ 4.152 minutes
So, it would take approximately 4.152 minutes to burn 5 kcal at rest on a high carbohydrate diet with a resting VO2 of 0.25 LO2/min.
Compare the number of calories in 2 plates of food weighing 1lb (454g) each and consisting of either fat or carbohydrate? (taking into account 1g of stored carb = 4 kcal and 1g of stored lipid = 9 kcal)
9/4 = 2.25
review practice questions on page 53
