Applied Exercise Physiology Flashcards
What are the 3 broad reasons that we require energy for?
Resting metabolic rate, thermic effect of food, ATP (adenosine triphosphate)
What is ATP made up of?
An adenosine molecule and 3 phosphates
How does ATP release energy?
When the chemical bonds between the phosphate break
What is the primary source of energy in the body?
ATP
What enzyme causes the phosphate bonds to break?
ATPase
ATPase uses what?
Water
The process of ATPase breaking the bonds is called?
Hydrolysis
A word ending in ‘lysis’ means?
That something has been chemically broken
What are macronutrients?
Carbohydrates, fats, proteins
Macronutrients are broken down during … and absorbed into the …
Digestion, bloodstream
Carbohydrate is broken down and used as … or stored as … in the liver or muscles
Glucose, glycogen
Fat is converted into?
Fatty free acids
FFA are used for energy or stored as …. in adipose tissue, or within muscle
Triglycerides
Protein is broken down into?
Amino acids
Where are amino acids stored?
In muscles and other tissue
ATP is produced via?
3 metabolic pathways
What are the three metabolic pathways?
Phosphocreatine system, glycolytic system, oxidative system
What is anaerobic metabolism?
It produced ATP without the use of oxygen
Which two pathways are anaerobic?
PCr and glycolytic
Anaerobic metabolism takes care of what type of energy requirements?
Immediate and very short term energy requirements
The anaerobic systems occur in what area of the muscle?
Sarcoplasm
PCr system deals with?
Immediate ATP requirements and also during very high intensity efforts
How many times more PCr than ATP is there stored in the body?
4x
PCr use is restricted to the first how many seconds of movement?
6-10seconds
During very high intensity, PCr is the … of ATP
Primary provider
How many ATP molecules does PCr produce per chemical reaction?
1
How does the glycolytic system produce ATP?
Through the process of glycolysis
What is glycolysis?
The breakdown of glucose or glycogen to produce ATP
Is the glycolytic system slower or faster than PCr?
Slower
Which produces more ATP, PCr or glycolytic?
Glycolytic
What time period of movement does glycolytic system provide ATP for?
The first few minutes. And is also the main provider of ATP during high intensity efforts lasting up to 2 minutes
How many ATP molecules does the glycolytic system produce?
2 or 3. Depending whether glucose or glycogen is used
Glycolysis involves a series of chemical reactions the produce?
A small number of ATP molecules, pyruvate and H+
When O2 supply is … or demands for ATP are high, … is converted into lactic acid
Insufficient, pyruvate
Why is glycolysis short lived?
Because the metabolic by products of glycolysis build up and slow or inhibit further ATP production
Lactic acid quickly breaks down into?
Lactate and hydrogen ions
If oxygen is present, or ATP demand drops, lactate can be converted back to?
Pyruvate
Alternatively lactate can be moved out of the muscle into the blood stream. From here it can be used in the liver or taken up and used by?
Type I muscle fibres
The aerobic system is also known as the what system?
Oxidative
The aerobic/oxidative system is the slowest or fastest system?
Slowest
Does the aerobic/oxidative system produce more ATP that PCr?
Yes
Aerobic metabolism provides the …. of energy during activities lasting longer than … minutes
Majority. 4 minutes
The two step process of aerobic metabolism occurs when oxygen supply is … or energy demands are …
Adequate. Low
The two step process occurs where?
In the mitochondria
The first process can use either …. (from glycolysis) or the end product of beta-oxidation to produce ….
Pyruvate. Acetyl-CoA
Acetyl-CoA undergoes a number of chemical reactions which is collectively called the?
Krebs cycle
The Krebs cycle produces how many ATP?
2
The second process is called?
The electron transfer chain
The electron transfer chain uses the … from the Krebs cycle and … and O2 from the air we breath to produce ATP and H2O
H+ and glycolysis
Depending on whether glucose or FFA is used how many ATP molecules are produced?
Either 36 or 129
The fate of pyruvate depends on?
The demand for energy
If demand for energy is low what can pyruvate be used for?
ATP production in the mitochondria
If energy demand is high, pyruvate is converted into?
Lactate
PCr produces how many ATP molecules?
1
Anaerobic metabolism produces how many ATP molecules?
2 or 3
Oxidation of carbohydrate produces how many ATP molecules?
36
Oxidation of fat produces how many ATP molecules?
129
Which system has the fastest rate of ATP production?
PCr
Which system has the slowest rate of ATP production?
Oxidation of fat
During muscle contraction in the first 10 seconds of movement, what provides most of the ATP?
Stored ATP and PCr
As PCR levels decrease, what then provides ATP?
Anaerobic glycolysis
After anaerobic glycolysis decreases, what is the next system?
Aerobic/oxidative
The neuromuscular system is made up of?
Central nervous system and skeletal muscle
A motor unit is?
Motor neurons (nerves) and the muscle fibres the neurons innervate
For a motor unit to be activated it must?
Receive a signal from the brain
The all or none theory is?
When a signal is sent to a motor unit, all of the fibres in that motor unit are activated
The type of motor unit, rate of recruitment and number of motor units recruited determines?
How much force is produced
The main proteins that make up skeletal muscle are?
Actin and myosin
Actin and myosin are found in a contractile unit called the?
Sarcomere
What is the process called when actin and myosin interact to cause muscle contraction?
Sliding filament theory
What dictates muscle recruitment?
The size principle
The size principle refers to?
The size of the motor unit affecting the recruitment of various fibre types
To produce a required force, motor units are recruited (activated) from ….
Smallest to largest
What happens if more force is needed?
Additional small motor units and slightly bigger motor units are recruited
When are almost all motor units recruited?
When maximal force is required
What size units are recruited first?
Small
What fibres are found in small motor units?
Type I fibres
Type I fibres are also referred to as?
Slow twitch fibres
Type I fibres have a very good …, a high volume of … and …, and rely on O2 to produce …
Blood supply. Mitochondria and myoglobin. ATP
Type I fibres are … resistant
Fatigue
Their small size and slow contraction rate means that these fibres produce … force and power
Low
The next type of fibres are?
IIa
IIa fibres can produce high … and …, and have a … level of fatigue resistance
Force. Power. Moderate
They can produce ATP with or without ….
O2
The largest motor units are made up of what fibres?
Type IIx
These fibres are recruited …
Last
Iix fibres are used for …., …. movements and movements that require a lot of ….
Fast, powerful. Force
These functional characteristics are due to?
Very fast nerve signals, fast contraction and relaxation rates, and the large diameter of fibres
If a fibre has more actin and myosin that means it is a …. …. fibre?
Large diameter
Because type Iix fibres are required to contract rapidly they rely on …., … and …. for ATP supply
Stored ATP, PCr and anaerobic glycolysis
Which types of fibres fatigue the most quickly?
Type IIx
What two fibres are referred to as fast twitch fibres?
Type IIa and type IIx
