Exercise Physiology Unit 1 exam

Why do we need to understand terminology?

• Describe intensity

• Describe volume

• Energy Expenditure

• Efficiency of Work

Force is that which…

alters a state of motion

Newton (N) =

force to move 1 kg at 1 m/s²

Kilopond (kp)

gravitational force acting upon 1 kg mass on Earth

Force =

kp

mass =

kg

Work=

F*D

Power is the

rate of work

Power =

Work/t

Power is expressed as

• Watts

• J/s

• kpm/min

1 Watt =

6.12 kpm/min

Ergometry=

measurement of work output

Ergometer=

device used to measure work

Common types of ergometers

• bench step ergometer

• cycle ergometer

• Arm ergometer

• treadmill

Energy=

capacity to do work

Forms of energy

• motion (kinetic)

• position (potential)

• light

• heat

1 kcal is the

energy required to raise 1 kg of water by 1 degree celsius

1 kcal =

4.186 kJ

Net efficiency

ratio of mechanical work to energy needed to do that work

___-____% net efficiency in humans

20-25%

Exercise intensity

• curvilinear relationship between work rate and energy expenditure

  • efficiency decreases at high exercise intensities because of higher energy cost of very heavy exercise

Speed of movement

there is optimum speed of movement and deviation away from optimum speed reduces efficiency

Muscle fiber type

slow muscle fiber (type 1) are more efficient in using ATP compared to fast muscle fibers (type 2)

Homo\eostasis

maintenance of a constant and “normal” internal enviorment

Steady state

physiological variable is unchanging but not necessarily normal

Intracellular control systems

• protein breakdown and synthesis

• Energy production

• Maintenance of stored nutrients

Organ control systems

• pulmonary and circulatory systems

  • replenish O2 and remove CO2

Components of biological control systems

• sensor/receptor

• control center

• effectors

sensor/receptor

detects change

control center

assess input and initiates response

effectors

changes internal environment back to normal

Negative feedback

response reverses the initial disturbance in homeostasis

• ex: increase in CO2 triggers breathing adjusments

Positive feedback

response increases the original stimulus

• contractions and oxytocin release during childbirth

Gain of control system

degree to which a control system maintains homeostasis

high gain=

better at maintaining homeostasis

exercise disrupts

pH, PCO2, PO2, and temp in cells

Failure occurs during

intense or prolonged exercise in hot environments leads to fatigue and cessation of exercise

Adaptation

change in structure and function improving ability to maintain homeostasis

Acclimation

adaptation to environmental stresses

Hormesis

low to moderate does of harmful stress leads to an adaptive response

Exercise-induced hormesis drives___

exercise induced adaptation in the body

Metabolism=

sum of all rxns that occur in the body

two categories of metabolism

anabolic and catabolic rxns

Anabolic rxns

Synthesis (store E)

Catabolic rxns

Breakdown (release E)

Bioenergitics=

process of converting food into useable energy for cell work

Important structures to exercise physiology:

• Cell membrane

• Cytoplasm

• Nucleus

• Mitochondria

Cell membrane

phospholipid bilayer, semipermeable, keeps things out and in

Cytoplasm

suspends cells organelles in space, holds water and nutrients

Nucleus

houses DNA

Mitochondria

powerhouse of the cell, makes E

Endergonic Rxns

energy requiring rxns(anabolic)

Exergonic rxns

release of E (catabolic)

Coupled rxns are rxns that are ____

linked with the liberation of free E in one rxn being used to drive a second rxn

Oxidation-reduction rxns transfer

electrons

NAD

oxidized form_____

Reduced form_____

• NAD+

• NADH

FAD

oxidized form:

reduced form:

• FAD

• FADH2

_______ are biological catalysts

enzymes

Enzymes do not cause a rxn to occur but simply____

regulate the rate or speed at which the reaction take place

enzymes are large ____ molecules with a unique shape

protein

The active site binds to the _____ to form an _______

• substrate

• Enzyme-substrate complex

Enzymes lower the. ______ of a rxn

activation energy

After the rxn the enzyme ___

dissociates

Factors that affect enzyme activity

temperature and pH

Enzymes are _____ during a rxn

NOT CONSUMEd

The three biomolecules are

• CHO

• Fats

• Proteins

Types of CHO

• Glucose

• Glycogen

Types of Fats

• Fatty Acids

• steroids

• phospholipids

Types of proteins

• Amino acids

Functions of biomolecules

• ATP production

• Strucurla functions

• Hormonal functions

what biomolecules are involved in ATP production?

• primarily glucose, glycogen, and FAs

• use proteins only when there is very low E available

What biomolecules are involved in structural functions?

• Phospholipids

• Steroids

• amino acids

What biomolecules are involved in hormonal functions

• steroids

• amino acids

ATP consists of

• adenine

• ribose

• 3 linked phosphates (store a lot of E)

Types of phosphorylaton

• Substrate level

• Oxidative

Substrate level phosphorylation:

PCr, anaerobic glycolysis, and aerobic metabolism

Oxidative phosphorylation

Aerobic metabolism

Formation of ATP

• ATP-PC system

• Glycolysis, Glycogenolysis

• Oxidative formation of ATP/Aerobic metabolism

Anaerobic pathways for formation of ATP

• Substrate level phosphorylation

  • ATP-PC

  • Glycolysis

aerobic pathways for formation of ATP

• Oxidative phosphorylation

  • Aerobic metabolism

Where does ATP-PC system and glycolysis happen

cytoplasm

where does Krebs and ETC occur

mitochondria

ATP-PC/PCr system

• yield 1 ATP per PCr

• active during short-term, high intensity exercise

• lasts 5-15 seconds

• rate limiting enzyme: Creatine phosphate

Glycolysis system

• 1 glucose = 2 ATP(net), 2 NADH, 2 pyruvate

• 1 glycogen= 3 ATP (net), 2 NADH, 2 Pyruvate

• Active during high intensities

• lasts 10s to 2-3 min

two phases of glycolysis

• Energy investment phase

• energy harvesting phase

Energy investment phase

• loss of 2 ATP

• shift from 6-C ring, to 6-C chain, to 2 three carbon chains

Energy harvesting steps

• 4 ATP produced

• 2 NADH produced

• 2 Pyruvate produced from the 2 3-C chains

Fate of pyruvate with O2

pyruvate to Acetyl CoA to Krebs

Fate of pyruvate w/o O2

Pyruvate to Lactate

Limiting enzyme in Aerobic glycolysis

PFK

Limiting enzyme in anaerobic glycolysis

LDH

Aerobic metabolism

• Active during exercise lasting longer than 3 sec

• starts in cytoplasm and ends in mitochondria

• steps: glyoclysis, CAC, ETC

Krebs Cycle (CAC)

• Pyruvic acid is converted into acetyl CoA and CO2 is given off

• Acetyl CoA combines with oxaloacetate to make citrate

• Citrate is metabolized to oxaloacetate and two CO2 molecules are given off

• Produces 3 NADH, 1 FADH, 1 GTP

ETC

• occurs in mitochondria

• electrons from FADH and NADH are passed along cytochromes to produce ATP

• h+ ions pumped across inner membrane and powers ATP production

• Final electron acceptor O2 forms H2O

rate limiting enzyme during Krebs

IDH

rate limiting enzyme during ETC

cytochrome c-oxidase

How much ATP generated through Oxidative respiration

32-34

Substrates for PCr system

PCr

substrates for glycolysis

Glucose/glycogen

substrates for Oxidative respiration

• Triglycerides

• Fatty Acids

• Amino Acids