Ex Phys study guide 1

Carbohydrates are the primary fuel for

moderate-to-high intensity exercise

Carbohydrates are stored as

glycogen

Where are carbohydrates stored?

muscle and liver

Carbohydrates provide quick

ATP production

Fats are the largest

energy reserve

Fats are stored as

triglycerides

Fats are a major fuel during

low-intensity, long duration exercise

Proteins are built from

amino acids

The primary role of proteins is

tissue repair and synthesis

Proteins are a minor energy source during

prolonged exercise

High intensity uses a greater amount of

carbohydrates

longer duration uses a greater amount of

fats

Potential Energy

stored energy

Kinetic energy

energy of motion

Bioenergetics

energy transfer in living systems

Endergonic

requires energy input

Exergonic

releases energy

Oxidation

loss of electrons

Reduction

gain of electrons

Mechanical work

muscle contraction

Transport work

moving substances across membrane

Chemical work

building molecules

Cellular respiration depends on

enzymes, coenzymes, mitochondria, and oxygen

Metabolism

all chemical reactions in the body

Anabolism

builds molecules

Catabolism

breaks molecules down

Substrate-level phosphorylation

direct ATP formation

Oxidative phosphorylation

ATP formation via ETC

Glycolysis

Breakdown of glucose

Lactate

product formed when pyruvate accepts hydrogen

Lactate threshold

point when lactate accumulates rapidly

Glycogenolysis

breakdown of glycogen

Gluconeogenesis

creation of glucose from non-carb sources

Chemiosmosis

proton gradient driving ATP synthesis

Lipolysis

breakdown of triglycerides

Beta-oxidation

fatty acid breakdown

Deamination

removal of amino group from amino acids

Creatine kinase

ATP-PCr reaction

Lactate dehydrogenase

pyruvate ←→ lactate

Phosphofructokinase (PFK)

rate-limiting step of glycolysis

Pyruvate dehydrogenase

converts pyruvate → Acetyl-CoA

ATP synthase

Produces ATP in ETC

Hormone sensitive lipase

stimulates fat breakdown

ATP-PCr system is the fastest

ATP production

ATP-PCr system dominates

first ~10 seconds

ATP-PCr system uses

phosphocreatine

ATP-PCr system enzyme

creatine kinase

ATP-PCr system supports

sprinting, jumping, heavy lifting

ATP-PCr system training can

increase phosphocreatine stores

Rapid glycolysis starting substrates

glucose, glycogen

Rapid glycolysis end products

ATP, pyruvate (or lactate is oxygen is insufficient)

When oxygen availability is limited

pyruvate → lactate

Lactate is important because it

can be used as fuel and helps sustain energy production

Lactate shuttle

lactate produced in one tissue and used elsewhere

Cori cycle

Lactate travels to live, converted back to glucose

Rapid vs. slow glycolysis

R: oxygen limited, S: oxygen sufficient

Pyruvate dehydrogenase reaction

pyruvate → Acetyl CoA, produces NADH and CO2

Citric acid cycle input

Acetyl-CoA

Citric acid cycle outputs

NADH, FADH2, ATP (GTP), CO2

Chemiosmosis protons move through

ATP synthase

Chemiosmosis energy is used to make

ATP

Lipolysis

triglyceride → glycerol + fatty acids

Beta-oxidation

fatty acids → Acetyl-CoA enters CAC

Glycerol

enters glycolytic pathways

Triglycerides

yield much more ATP than glucose

Glucogenic amino acids

form glucose intermediates

Ketogenic amino acids

form ketone-producing molecules

VO2

oxygen consumption

VO2max

maximum oxygen consumption

Oxygen deficit

lag before steady-state oxygen use

EPOC

excess postexercise oxygen consumption

Steady state VO2

oxygen demand equals oxygen supply

RQ

CO2 produced/O2 consumed at cellular level

RER

measured respiratory ratio

VO2max includes a plateau in

oxygen uptake

VO2max includes high blood

lactate

VO2max includes near-maximal

heart rate

VO2 max includes high

RER

Fast EPOC replenishes

ATP-PCr

Fast EPOC restores

oxygen

Slow EPOC regulates

temperature

Slow EPOC recovers

hormones

Slow EPOC processes

lactate

Crossover concept X-axis

exercise intensity

Crossover concept Y-axis

fuel contribution

As intensity increases, fat use

decreases

As intensity increases, carbohydrate use

increases

Direct calorimetry

measures heat production

Indirect calorimetry

uses oxygen consumption and CO2 production

Doubly labeled water

measures free-living energy expenditure

Three components of TDEE

BMR, physical activity, thermic effect of food

Largest influence of BMR

lean body mass

Largest influence on physical activity

movement/exercise

Largest influence of TEF

food intake

Three major determinants of endurance performance

VO2max, lactate threshold, movement economy

Movement economy

oxygen cost as a given workload

Better movement economy =

lower oxygen use, better performance

< 10 sec

ATP-PCr

30 sec to 3 min

glycolytic

>3 min

oxidative