Midterm #2: Energy Systems-Ventilation Response to Exercise

creatine phosphate

the alactic anaerobic component of the phosphagen system is?

because only a small amount of ATP is stored in the muscle cell, so as it depletes we need a energy system to resynthesize ATP rapidly.

why is the phosphagen system necessary?

1.) muscle
2.) 10-20 seconds

creatine phosphate is stored in 1.)____________________ cells and there is only enough stored to fuel the first 2.)____________ sec of exercise.

1.) enzyme creatine kinase breaks high energy bond between C and P, releasing high energy.
2.) kinase then utilizes the energy to phosphorylate an ADP molecule to synthesize ATP.

how is creatine phosphate (c=p) utilized for the resynthesis of ATP?

an increase in creatine phosphate reforming more ATP from ADP.

increase in ATP consumption during the first 10-20 seconds of exercise = ?

to provide "quick release energy" (about 15 seconds)

what is the purpose of creatine supplementation?

creatine attaches to water & causes dehydration in the circulation.

how is creatine supplementation linked to "muscle cramps"?

2.4 mmol ATP/g/kg wet wt.

what is maximum ATP regeneration rate of the phosphagen system?

blood
liver

the main supply of glucose that enters glycolysis comes from the? (2 places)

glucose
because the final product of glycolysis will enter muscle cells (under anaerobic conditions) to take up protons and produce lactate, which acts as a temporary buffer.

the lactic anaerobic component of glycolysis is? why?

10-20 minutes

after exercise, how long does it take for blood lactate levels to decrease?

rate-limiting step(s)

the part of a reaction that is the slowest to complete and requires the highest amount of energy.

1.) glucose + P ------------> glucose-6-phosphate + ADP
*catalyzed by enzyme: Hexokinase
*requires 1 ATP (net -1)
3.)fructose-6-phosphate + P ------------> fructose-1,6 biphosphate
*catalyzed by enzyme: Phosphofructo-kinase
*requires 1 ATP (net -2)

what are the 2 rate limiting steps of glycolysis? what steps do they occur at?

hormone insulin binds to insulin receptors on cells, which then opens GLUT channels that glucose can use to enter cells. (no ATP needed, going from high-to-low concentration).

how is glucose able to enter the cells from the blood?

the glucose is immediately converted into glucose-6-phosphate and this prevents it from leaving the cell.

glucose must be concentrated and stored within cells, what keeps it from leaking out?

1.3 mmol ATP/g/kg we wt.

what is maximum ATP regeneration rate of the glycolytic system?

+2 net ATP

what is the overall net ATP after the completion of glycolysis?

1 glucose
2 ATP
2 NAD

What are the inputs of glycolysis?

2 pyruvate
2 ATP
2 NADH 2 H+

What are the outputs (products) of glycolysis?

8 ATP

What is the total amount of ATP produced from glycolysis?

1.) take up 2 hydrogen ions (protons) and become lactate to act as a temporary buffer to help the muscle cell return to adequate pH level.
2.) if lactate accumulates, no more ATP is produced.

in anaerobic conditions (poor O2), pyruvate molecules will...(2 paths)

1.) travels to mitochondria and becomes oxidized to create 2 acetyl-CoA, the molecule needed to begin the citric acid cycle.
2.) is completely combusted and more ATP is produced.

in aerobic conditions (good O2), pyruvate molecules will...(2 paths)

True

T or F: lactate accumulation under anaerobic conditions inhibits phosphofructokinase (PFK)?

True

T or F: lactate is able to be converted back to pyruvate if pyruvate levels are lowered.

35%
reduce

research indicates that performing light exercise at ___________ of a persons VO2 max can significantly _____________ blood lactate levels compared to doing "nothing" afterwards.

shuttles the H+ ions into the mitochondria.

in aerobic conditions, NAD does what with the hydrogen ions produced from glycolysis?

Glycolytic shunt

occurs when glycolysis proceeds rapidly in hypoxic (lacking O2) conditions

1.) glucose is split into 2 three-carbon units
2.) one unit is 1-3 DPG
3.) 1-3 DPG is catalyzed by mutase to make 2-3 DPG
*importance? 2-3 DPG will interact with hemoglobin and to increase the release of O2 at tissues.

explain the mechanism of the glycolytic shunt? (3 steps)

1.) carbohydrates
2.) fats
3.) amino acids

the 2-carbon atoms that enter the citric acid cycle are derived from?

(3) NADH
(2) FADH2
(1) GTP
H2O and CO2
1 cycle = 12 ATP
2 cycles = 24 ATP *more accurate since 2-carbon atoms enter cycle.

what are the products of the citric acid cycle? how many ATP are produced in 1 cycle? 2 cycles?

38 total ATP (w/o glycogen)
39 total ATP (w glycogen)

in total, how many ATP are produced from Glycolysis, shuttling of electrons, and the citric acid cycle?

O2

in aerobic (cellular) respiration, what is the final electron acceptor?

because the energy released from the breakdown of glucose molecules is used to synthesize ATP.

why is aerobic respiration considered a "coupled reaction" ?

creatine kinase

what is the main controller (enzyme) of the phosphagen energy system?

phosphofructokinase

what is the main controller (enzyme) of the glycolytic energy system?

isocitrate dehydrogenase

what is the main controller (enzyme) of the citric acid cycle energy system?

cytochrome oxidase

what is the main controller (enzyme) of the electron transport chain?

phosphorylase

what is the main controller (enzyme) of glycogen breakdown?

pyruvate is converted into fatty acyl CoA. Once inside the mitochondria, fatty acyl CoA is converted into Acetyl-CoA and is ready to enter the citric acid cycle.

what is "beta-oxidation" and where does it occur?

as electrons are transported down the ETC by NAD and FADH+...
protons are pumped across the inner-mitochondrial membrane...
which results in a proton gradient necessary to power the synthesis of ATP.

what is the chemiosmotic hypothesis?

higher

within the mitochondrial matrix, the pH is ___________.

lower.

within the intermembrane space, the pH is __________.

1.) passage of air through respiratory passages and lungs (ventilation)
2.) diffusion of respiratory gases between alveoli (in lungs) and pulmonary capillaries
3.) transport of O2 and Co2 through the blood (hemoglobin)
4.) diffusion of respiratory gases b

explain the steps of external respiration (4 steps)?

Internal respiration

the utilization of O2 and production of CO2 in metabolic reactions to produce energy (in mitochondria)

inspiration

taking air into the lungs

expiration

expelling air out of lungs

Eupnea

normal respiration

Apnea

cessation of respiration

Dyspnea

irregularities of respiration

Hypernea

increase in respiratory rate (frequency) and depth (tidal volume)

Minute ventilation (Ve)

Ve = freq. x Vt

S: Standard; reference condition
T: Temp.; 0 deg. celsius or 273 K
P: pressure.; 760 mmHg (atmospheric)
D: Dry; no moisture or humidity

Define the gas law "STPD

A: ambient (air)
T: temp (room temp)
P: pressure (barometric)
S: saturated (moisture, humidity)

Define the gas law "ATPS

B: body
T: temp
P: pressure (47 mmHg- vapor pressure of H2O at body temp)
S: saturated (moisture, humidity)

Define the gas law "BTPS

Charle's Law

defined as the change in temperature, determined by the ratio of initial (T1) to that of the final corrected temperature (T2), is equal to the change in volume.
T1/T2 = V1/V2

Boyle's Law

states that gas volume is inversely related to pressure, so an increase or decrease in pressure of a gas (at a constant temp) causes a proportional decrease or increase in volume
P1/P2 = V2/V1

Henry's Law

the volume of gas dissolved in liquid is proportional to its partial pressure and its solubility

O2
we breath in oxygen and need a higher partial pressure than CO2 in order for the exchange to occur effectively.

which of these molecules (O2 or CO2) has a greater partial pressure in the lungs? why?

CO2
because 98% of all oxygen molecules are taken up by hemoglobin protein, which is insoluble.

which of these molecules (O2 or CO2) is more soluble in the body? why?

quiet breathing

defined as inspiration active, expiration passive

False

T or F: during exercise, expiration cannot become active?

abdominal and internal intercostal muscles contract, which boosts the lung's recoil

How does expiration become active during exercise?

minute ventilation

the total amount of gas moved per minute

Vi or Ve = f x Vt
f = frequency
Vt = amount of expired air in one breath
SINCE Vi = Ve!

what is the equation used for determining Vi? what about Ve?

disease occurs (i.e. COPD)

if inspired amounts of oxygen and expired amounts of oxygen are not similar, what happens?

because different body sizes, sex, and age can have an impact on the value.

why are Ve (expiration) at rest variable across individuals?

6 L/min

what is the normal resting Ve value for a trained individual?

intensity can be used to predict Vo2 max!

explain a typical VO2 maximum graph and the linear relationship that exists between intensity and VO2

a trained individual will have a higher VO2 max than the untrained individual.
trained individual will achieve steady state much quicker and will activate aerobic energy systems faster and will be able to effectively take in oxygen to fuel the exercise
un

what is the difference between a trained individual's VO2 max and an untrained individual's VO2 max?

1.) elevated hormones (i.e. epinephrine, glucagon)
2.) post-exercise HR elevation of HR and breathing
3.) increase in body temperature
4.) restoration of muscle and blood O2 stores
-myoglobin (muscle) and hemoglobin (blood)
5.) lactate removal
6.) resynth

what are the factors that contribute to EPOC (6 total)?

represented on graph: the point at which we can see an exponential increase in blood lactate levels
physiological explanation: this exponential increase is caused by our bodies inability to remove lactic acid at an effective rate, to which this increase i

explain the lactate threshold and it's relationship to exercise intensity and blood lactate accumulation

1.) reduced rate of lactate removal
2.) recruitment of fast-twitch fibers
3.) accelerated glycolysis
4.) low muscle oxygen

what are the factors that contribute to reaching the lactate threshold? (4)

Forced Vital Capacity (FVC)

a method of dynamic spirometry used to determine the volume of gas that can be exhaled forcefully after a maximal inhalation

Forced Expiratory Volume (FEV 1.0)

a method of dynamic spirometry used to determine the volume of gas expired forcefully in one second.

80% FVC (based on a 25 y/o)

what is the normal percentage of the FVC that can be expired during 1 second?
*FEV 1.0/FVC

decreases

if an increase in airflow resistance occurs in the bronchial passageways, FVC ____________________?

Maximal Voluntary Ventilation (MVV)

a method of dynamic spirometry used to determine the largest volume of air inhaled and exhaled out of the lungs in a given time interval.
participant breathes as rapidly as possible throughout a time interval (i.e. 12-15 seconds), volume within interval i

a.) both can!
b.) 1.) airway resistance (increases secretions and blocks air)
2.) bronchoconstrictions
3.) compliance (elasticity of respiratory tissues)

a.) Which type of spirometry: FEV 1.0/FVC or MVV can be used to measure obstruction?
b.) what factors contribute to airway obstruction? (3)

residual volume

the volume of air always present in the lungs, even when exhaling deeply
without this, our lungs would collapse!

neurogenic factors

rapid regulator components of respiration are due to ___________________ ?

humoral factors (substances in the blood)

slow regulator components of respiration are due to ___________________ ?

1.) nerve impulses from receptors in blood vessels near the heart & lungs
2.) stimulation from receptors in joints and muscles (via feedback)
3.) stimulation from limbic system and motor cortex
the respiratory control center located in the medulla oblonga

where are the 3 areas we receive rapid regulator components of respiration? where are the signals from all 3 of these transmitted to?

M: memory
O: olfaction
V: visceral
E: emotions

The limbic system is best explained by the acronym: M.O.V.E., what do each letter stand for?

chemoreceptors

a class of receptor that detects changes in CO2, O2, and pH.

mechanoreceptors

a class of receptor that responds to mechanical stimuli, such as touch or sound.

hypoxia

when the body/region of the body is deprived of oxygen

signal for the increase in cardiac output to increase the amount of oxygenated blood throughout the body.
cardiac output increases even more dramatically.

in response to a hypoxic environment (i.e. PaO2 < 100 mmHg), carotid bodies do what? what about at < 60 mmHg?

hypoxia

augments response to increasing levels of Co2

acidemia

augments response to decreasing levels of O2.

increase in potassium ions
increase in CO2 (most potent stimulator)
increase in lactic acid
decrease in oxygen
decrease in pH

What are the 5 humoral factors part of the slow regulator components of respiration?