A.V. Hill
heat production during muscle contraction and recovery.
Otto Meyerhof
relationship oxygen (O2) consumption and lactic acid in muscle
August Krogh
function of capillary circulation
D.B. Dill
conducted Harvard Fatigue Laboratory from 1927-1947.
Independent Variable
manipulated by researcher (x-axis)
ex: intensity, duration, frequency
Dependent Variable
changes in response to independent variable, can NOT control (y-axis)
ex: blood pressure, heart rate, fatigue
Homeostasis
maintaining balance in normal or "internal" environment
ex: 37'C and pH 7.4
Steady State
balance between demands placed on the body and the bodies response to those demands. This is disrupted when you reach your max or body demands change
What are two control systems are employed by the body to maintain or restore homeostasis?
Intracellular
Organ
What is the purpose of a biological control or feedback system?
mechanisms that respond to stress to keep homeostasis
Negative Feedback
reverse initial stimulus to bring back to norm
Positive Feedback
enhances the stimulus
Sensor
detects stimulus and sends signal to control center (afferent)
Control Center
receives and asses info given and sends to effector (efferent)
Effector
makes a change via muscles and glands
Intracellular System
reside inside the cell; regulates activities such as protein breakdown, synthesis, and energy production
Organ System
helps maintain homeostasis; pulmonary and circulatory systems work together to replenish oxygen and remove carbon dioxide to keep homeostasis during exercise
Organic Compounds
contain carbon
Inorganic Compounds
do NOT contain carbon
Mitochondria
powerhouse of cell involved in oxidative conversions of food stuffs
Endergonic
needs energy to be added to reactants
Exergonic
reactions that give off energy
Coupled Reactions
reactions that are linked with liberation of free energy and being use to drive a second reaction; release of exergonic derives endergonic reaction
Oxidation
removing an electron; coupled reaction
molecule that donates an electron is reducing agent
Reduction
addition of electron; couples reaction
molecule that accepts an electron is oxidizing agent
NAD+
oxidized;
derived from B3
NADH
reduced
NAD+ +H+=NADH
Enzymes
catalyst protein (amino acids) play a role in speeding up or catalyzing chemical reactions
altered by temp and pH
ends in "ase"
lower energy of activation to speed up chemical reactions
Coenzymes
activate enzyme
water soluble B vitamin
What are Carbohydrates composed of and how many k/cals does it contain?
composed of carbon, hydrogen and oxygen
4 k/cal
Carbohydrates
stored as glucose in blood sugar (C6H12O6)
What are the 3 Forms of carbohydrates?
monosacceride, disacceride, and polysacceride;
these are sugars containing glucose and fructose
Glycogen
is a polysacceride (CHO) where cells breakdown glycogen to glucose in the liver and muscle which is called "glycogenolysis
What are fats composed of and how many k/cals does it contain?
composed of carbon and oxygen
9k/cal
What are the 4 types of fat?
fatty acids, triglycerides, phospholipids, and steroids
Fatty Acids
long chain stored as triglycerides
ex; saturated fat, unsaturated fat, monosaturated fat, and polysaturated fat
Triglycerides
fatty acids and 1 molecule of glycerol in skeletal muscle "lypolysis
Phospholipids
not used as energy source but structural of cell membrane insulating sheath around nerve fibers
Steroids
cholesterol, and synthesize sex hormones
What are proteins composed of and how many k/cals does it contain?
composed of carbon, hydrogen,oxygen, and nitrogen
4k/cals
Proteins
composed of amino acids that contributes as fuel in muscle;
can be converted in the liver into glucose and synthesize glycogen or converted into fuel in metabolic pathways
ATP
adenine triphosphate; energy carrying molecule
synthesis;ADP +Pi---- ATP
breakdown; ATP+ + H2O---ATPase---->ADP + Pi + Energy = muscular contraction
What is metabolism and describe the two types?
state of all chemistry in the body;
anabolic-build (chronic)
catabolic-breakdown (acute)
Glycogenolysis
breakdown of glycogen to glucose;
enzyme phosphorlase
Glycolysis
occurs in sacroplasm of muscle cell
breakdown of glucose or glycogen into two molecule of pyruvate and two molecules of lactate
net gain of 2 ATP
Proteolysis
breakdown of protein;
enzyme protase
Lipolysis
breakdown of triglycerides into lipolysis or fatty acids
Cell membrane
semi permiable; filters
Nucleus
contains protein synthesis
Cytoplasm
contains organelles, cytosol, and mitochondria
Gluconeogenesis
breakdown of fat and protein to make glucose
ATP-PCr System
(Phosphagen System)
does not involve O2 (anaerobic)
short term, high intensity exercise lasting fewer than 14 seconds
ex; 50 M, high jumping
muscle cells store small forms so it is LIMITED
What enzyme breaks down the ATP-PC System?
catalyzed by creatinekinase;
PCr + ADP--creatinekinase---ATP
high energy, 5 or 6 times greater concentration that ATP does
conducts muscle contraction in muscle cells
1.8 k/cal mol
What are the three immediate energy sytstems?
ATP;first cellular source of energy
PCr; 2nd cellular source of energy
myokinase enzyme; 3rd cellular source of energy
ATP hydrolysis
first cellular energy system;
ATP + H2O--ATPase--> ADP + Pi + Energy
8.4 k/cal mol
Myokinase
3rd cellular source of energy
has the ability to take two ADP and create one ATP
ADP + ADP --myokinase-- ATP +AMP
.9k/cal mol
Non Oxidative Energy System (Fast Glycolysis)
does not involve O2 (anaerobic)
from glucose and glycogen only CHO
from 10-14 sec
Oxidative (phosphorylation) Energy System
requires O2 (aerobic)
endurance activities
requires glucose and glycogen in slow glycolysis
fatty acids and amino acids
What are the two phases in the Non Oxidative (Fast Glycolysis) Energy System?
1)energy investment phase
2)generation phase
Energy Investment Phase
stored ATP is used to form sugar phosphate
contains glucose (6-Carbon mol) C6H12O6
requires 2ATP
formation of two 3-Carbon molecules
Energy Generation Phase
two 3-Carbon molecules formed
formation of two 3-Carbon pyruvate or two 3-Carbon lactate which releases energy
How many ATP and NADH are formed in the energy investment phase?
4 ATP produced
2 NADH molecules
What is the net gain of ATP in fast glycolysis?
2 ATP
What metabolic pathways are capable of making ATP without oxygen?
ATP-PCr System and Glycolysis
What happens when there is no oxygen present in glycolysis?
Pyruvate catabolizes lactate by the enzyme lactatedehydroganase (LDH) into lactic acid
NADH + H---LDH----NAD REDUCTION
Pyruvate
C3 catabolizes to Acetyl CoA (C2)
becomes C2; remaining carbon is given off as CO2
REDUCTION
Aerobic ATP Production
involves interaction of two metabolic pathways;
krebs cycle (citric acid cycle)
electron transport chain (ETC)
Krebs Cycle
complete oxidation (hydrogen removal) of CHO, fats, proteins, using NAD and FAD as hydrogen carriers
Acetyl-CoA
combines with oxaloacetate C4 to form citrate C6 whish then regenerates to oxaloacetate giving off n2 molecules of CO2
one molecule of glucose
0
How many molecules of NADH and FADH are formed in one turn of Kreb?
3 NADH
1 FADH
GTP
energy-rich compound derived from NADH and FADH; transfers phosphate group to ADP to ATP then taken to ETC.
Lactate dehydrogenase
this enzyme is activated when O2 is not available to accept H+ so pyruvate can accept the hydrogens in order to form lactate
CHO in Krebs
for every molecule of glucose entering glycolysis two molecules of pyruvate are formed causing 2 turns of Kreb giving off CO2
Fats in Kreb
are broken down to form fatty acids and use beta oxidation to form Acetyl-CoA to start kreb (lypolyisis give off electrons)
Proteins in Kreb
can be converted to glucose or pyruvate and some to Acetyl-Co A to start kreb (give off CO2 and NH3)
What are the four Rate Limiting Enzymes?
1) Creatine Kinase
2) Phosphofructosekinase
3) Isocitrate dehydroganase
4) Cytochrome oxidase
Creatine Kinase
ATP-Pc
Phosphofructosekinase
Glycolysis
Isocitrate dehydroganase
Krebs
Cytochrome oxidase
Electron Transport Chain
Yields 32 ATP (slow glycolysis)
aerobic metabolism of one molecule of GLUCOSE
Yields 33 ATP (fast glycolysis)
aerobic metabolism of one molecule of GLYCOGEN
Aerobic resperation
34% total energy
Energy released as heat-
66%
Is O2 present on the Kreb Cycle?
NOOO
Fate of Lactate 70%-
oxidized by other tissues (slow twitch)
Fate of Lactate 20%-
converted to glucose or glycogen in liver (cori CYcle)
Fate of Lactate 10% -
converted to amino acids
The higher acidity of the cell as a result of lactic acid production alters enzymatic activity
muscle fatigue
Absolute
L/min resting---- .25L/min resting
Relative
mL/kg/min------------- 3.5mL/kg/min resting
What is considered a low blood lactate level?
<1.0mmol/L
MET's
metabolic equivalents is the expression of energy costs for activites in a simple unit.
=3.5mL/kg/min (resting)
5 Criteria for VO2 Max
1- the plateau of oxygen consumption
2- the attainment of RER of 1-1.5 or higher
3- the attainment of age predicted heart rate
4- the exhaustion of the participant
5- blood lactate > 8.0 mM/L (resting <less than one)
Oxygen deficit
delay in O2 uptake at beginning of exercise
Does a trained/untrained individual have a higher or lower O2 deficit?
trained subjects have lower O2 deficit due to better developed aerobic capacity.
EPOC (Excess Post exercise Consumption
Post exercise, O2 concumption does not return to resting levels immediately; termed O2 debt
untrained individual have higher O2 debt because it takes longer to recover
Rapid Curve
steep decline in O2 consumption
replenish ATP, PC and oxygen stores
Slow Curve
slow decline in O2 consumption
elevated body temp
elevated epinephrine/epinephrine
elevated breathing and heart rate
conversion of lactic acid to glucose
EPOC ---Resythesize of PC in muscle
Fast Curve
EPOC---Restortion of muscles and blood oxygen stores
Fast Curve
EPOC---- Lactate Removal
Slow Curve
EPOC----Elevate body temp
Slow Curve
EPOC---- Elevated horomones
Slow Curve
EPOC---Postexercise elevation of HR and breathing
Slow Curve
What percentage of the lactate is oxidized by working muscle tissue?
80%
What percentage of lactate is reconverted into glycogen?
20%
Lactate Threshold
the point at which blood lactic acid arises systemically during incremental exercise
50-60% VO2 max in UNTRAINED
65-80% at higher work rates in TRAINED subjects
OBLA
Onset blood lactate levels reach 4mMol/L
resting 1m/mol
Metabolic CO2 Porduction
oxidative phosphorylation
non-metabolic CO2 production
bicarbonate buffering (HCO3-)
combines with hydrogen creating carbonic acid