October, 2, 2023

Question 1

what is DNA transcription

Answer 1

makes RNA

DNA → RNA

Question 2

what is DNA translation

Answer 2

makes protein

RNA → protein

Question 3

how do adaptations to exercise take place, leading to an altered phenotype. Explain what happens within the nucleus

Answer 3

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.

Question 4

what are the signals that will activate more mitochondrial synthesis

Answer 4

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)

Question 5

what is a common theme between the three signals that activate more mitochondrial synthesis

Answer 5

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

Question 6

phosphorylation of transcription factor leads to …..

Answer 6

activation of transcription

Question 7

how does the conversion of ADP to AMP occur

Answer 7

the higher the exercise intensity the more AMP you can make

Question 8

what two nutrients do you always burn/oxidize at the same time

Answer 8

carbohydrates and fats

Question 9

CD36

Answer 9

transport fatty acid into muscle cell

Question 10

page 50 is kind of a review of what we learned so far

Question 11

intramuscular sources of energy exist as….(refer page 50)

Answer 11

glycogen and triglyceride

Question 12

extramuscular sources of energy exist as….

Answer 12

fat: in adipose tissue

Carbs: in liver

Question 13

What is RQ

Answer 13

Respiratory Quotient

Volume CO2/Volume O2

Question 14

RQ = 1 (or around 1) means?

Answer 14

metabolizing carbs

Question 15

RQ = 0.7 (or around 0.7 ) means?

Answer 15

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).

Question 16

What does RQ values tell us:

Answer 16

what substrate we are using for energy

how many Kcals we are burning per LO2 consumed

Question 17

what does it mean when the RQ >1 in regards to Respiratory exchange ratio (RER) and buffering of lactic acid

Answer 17

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.

Question 18

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

Answer 18

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.

Question 19

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)

Answer 19

9/4 = 2.25

Question 20

review practice questions on page 53