Acid-Base Balance During Exercise
pH ranges from:
0-14
What is the normal ratio of bicarbonate to carbonic acid?
20:1
Hemoglobin has ________x the buffering capacity due to its higher concentration.
6
The pH of pure water is:
7
What is the survival range pH?
7.0-7.8
What is normal blood pH?
7.4
Sports lasting _____ can produce significant amounts of H+.
> 45s
Acidosis and alkalosis can lead to:
CNS dysfunction cardiovascular system dysfunction
A base is a molecule that is capable of combining with:
H+
A buffer consists of:
a weak acid and its conjugate base
Cardiovascular system dysfunctions include:
abnormal electrical acitivity
What increases H+ concentration?
acid
If the pH is less than 7 the solution is:
acidic
What is an ion?
atom that is missed or had gained electrons
If the pH is greater than 7 the solution is:
basic
When do phosphate groups work?
beginning of exercise
What is the most important buffering system?
bicarbonate
What are the four chemical buffers?
bicarbonate phosphate groups cellular proteins histidine-dipeptides
The Henderson-Hasselbalch equation describes the ability of:
bicarbonate and carbonic acid to act as a buffer system
What are the extracellular buffers?
bicarbonate, hemoglobin, blood proteins
What can be increased to improve performance?
blood buffering capacity
High-intensity exercise training improves:
buffering capacity
The first line of acid-base buffer is:
buffering of H+ in the muscle
What resists change to pH?
buffers
Why should someone be careful using sodium buffers?
can cause nausea and vomiting alkalosis
PCO2 determines the concentration of:
carbonic acid
The end products of oxidation are:
carbs, fats, and protein metabolism
What is an example of histidine-dipeptide?
carnosine
What are the types of intracellular buffers?
chemical buffers H+ transporters
What is pH?
concentration of H+ ions in a solution
What causes acidosis?
decrease in pH due to increased H+
Is deoxyHb or oxyHb better?
deoxyHb
Uncontrolled diabetes can cause:
diabetic ketoacidosis
Abnormal pH can:
disrupt normal body function and affect performance
What is pKa?
dissociation constant for carbonic acid
When does bicarbonate work?
during exercise
The greater the concentration of a buffer, the greater the:
effectiveness
In many sports, the risk of acid-base balance is related to:
effort of the competitor
Blood pH declines with increasing:
exercise intensity
H+ production depends on:
exercise intensity amount of muscle mass involved duration of exercise
True or false: Failure to maintain acid-base homeostasis has no consequences.
false
Limiting performance can contribute to:
fatigue
CNS dysfunction includes:
fatigue and mental confusion
What is the major blood buffer during rest?
hemoglobin
How do cellular proteins work?
histidine accepts H+ to form a weak acid
The ingestion of sodium buffers shows:
inconclusive data
When blood pH increases, there is a ______________ rate of bicarbonate excretion.
increased
How does high-intensity exercise training improve buffering capacity?
increases intracellular carnosine and H+ transporters
How does increase H+ impair performance?
inhibits enzymes in aerobic and anaerobic ATP production hinder muscle contractile process
What is the first line of defense for acid-base balance?
intracellular buffers
The ability of buffers to resist change depends on:
intrinsic physiochemical ability to act as a buffer concentration of buffer
What is important in long-term acid-base balance?
kidneys
Heavy exercise results in productio of:
lactic acid
Small quantities of blood proteins means:
limited use during exercise
What are two causes of metabolic acidosis?
long-term starvation uncontrolled diabetes
Hydrogen ions are formed by the:
loss of an electron
Muscle pH declines more dramatically than blood pH during exercise because:
lower buffering capacity
CO2 is 'blown off' by the:
lungs
How doe MCTs work?
mediate a one-to-one co-transport of lactate and hydrogen ions out of the muscle fiber
What is the gain in the amount of acid in the body called?
metabolic acidosis
What is the loss of acids from the body called?
metabolic alkalosis
How do NHEs work?
move sodium ions into the muscles and hydrogen ions out into the interstitial space
Both H+ transporters have:
one-to-one ratio
What is the Henderson-Hasselbalch equation?
pH = pKa + log [HCO3-]/[H2CO3]
What is alkalosis?
pH above 7.45
What is acidosis?
pH below 7.35
What causes alkalosis?
pH increases due to decreases H+
What is the equation to find pH?
pH=-log[H+]
Acid-base disturbances can limit:
performance
What are the sources of H+ ions during exercise?
production of CO2 production of lactic acid/lactate ATP breakdown
How does long-term starvation lead to acidosis?
production of ketoacids from fat metabolism
Why do we need to regulate pH?
rate of enzyme-controlled metabolic reactions shape and function on enzymes and proteins cell integrity
When blood pH decreases, there is a ______________ rate of bicarbonate excretion.
reduced
What is the purpose of kidneys for acid-base balance?
regulate blood bicarbonate concentration
An acid is a molecule that can:
release H+
What do buffers do when H+ concentration decreases?
release H+
What do buffers do when H+ concentration increases?
remove H+
Metabolic alkalosis is caused by:
severe vomiting kidney disease
What are two types of sodium buffers?
sodium bicarbonate sodium citrate
What are the two types of H+ transporters?
sodium hydrogen exchanger (NHE) monocarboxylate transporters (MCTs)
Bicarbonate (HCO3-) is a _____________ base.
strong
Lactic acid is a ____________ acid.
strong
What does pH represent?
the concentration of hydrogen ions in a solution
What type of fibers are more advantageous for performance during high intensity exercise?
type II
Blood proteins are buffers in the extracellular compartment that can form:
weak acids
