Ex Phys Exam 2

metabolism

sum of all anabolic + catabolic rxns

anabolic vs catabolic

synthesis vs breakdown

bioenergetics

turning foodstuffs into usable energy

endergonic vs exergonic rxns

requires vs releases energy

oxidation vs reduction

removing vs adding an electron

NAD vs NADH: ox or red?

ox vs red

FAD vs FADH: red or ox?

ox vs red

what do NAD and FAD do?

transport H+ to mitochondria for ATP generation

NAD

postal service: more frequent but carry less

FAD

Fed Ex: less frequent but carry more

what are enzymes and how do they work?

act as catalysts by lowering the activation energy, lock and key model

induced fit model

active site has to change shape to fit enzyme

factors that effect enzyme activity

temperature (gas)+ pH (breaks)

fuels for exercise progression

CHO → Fat → Protein

what factors affect what type of macronutrient fuel gets used?

duration, intensity, and type of exercise

gluconeogenesis

synthesis of glucose from non-CHO sources

glucose vs glycogen

highly regulated brain food vs storage form

Glycogenolysis

breakdown of glycogen to glucose

does muscle or liver store more glycogen?

muscle

fatty acids vs triglycerides

primary type used vs storage

ways ATP can be formed

PC breakdown, glycolysis, OxPhos

anaerobic pathways of forming ATP

PC breakdown + glycolysis

aerobic pathways of forming ATP

OxPhos

ATP-PC pathway

immediate source of ATP production, low yield

ATP-PC rate limiting enzyme

creatine kinase

when are PC stores used?

short term high intensity exercise <5 sec

does creatine improve performance?

yes for short term, high intensity exercise

where does gycolysis occur?

sarcoplasm of skeletal muscle

products of glycolysis (per 1 glucose)

glucose: 2 net ATP, 2 NADH, 2 pyruvate/lactate
glycogen: 3 net ATP, 2 NADH, 2 pyruvate/lactate

two phases of glycolysis

energy investment (ATP invested) + energy generation (4 ATP produced)

what enzyme needed to breakdown glycogen to glucose?

glycogen phosphorylase

glycolysis rate limiting enzyme

phosphofructokinase

2 ways to convert NADH to NAD

shuttle H+ into mitochondria + convert pyruvate to lactate

lactate

anaerobic end product, neutralizes H+ and offloads H+

pyruvate

aerobic end product, offload H+

lactic acid

lactate + H+

anaerobic glycolysis

NADH builds up, lactate is end product

aerobic glycolysis

NADH is used, pyruvate end product

when to use anaerobic vs aerobic glycolysis?

fast + short vs fast + long exercise

stages of OxPhos

formation of ACoA, Krebs cycle, ETC

purpose of Krebs Cycle

complete oxidation of ACoA

beta oxidation

fatty acids converted to ACoA, first stage of OxPhos when using fats

products of 1 turn Krebs Cycle

3 NADH, 1 FADH2, 1 GTP/ATP, 2 CO2

rate limiting enzyme of Krebs Cycle

isocitrate dehydrogenase

ETC

carrier molecules drop off H+, NADH @ complex 1 + FADH2 @ complex 2

where does ETC occur?

within the mitochondria

Chemiosmotic Theory

increase of H+ concentration outside of cell = gradient through ATP synthase = ATP

rate limiting step of ETC

cytochrome c oxidase

ATP produced per NADH + FADH

2.5 + 1.5

grand total ATP from glucose vs glycogen glycolysis

32 vs 33

overall efficiency of OxPhos

34%

T/F: all bioenergetic pathways are ALWAYS working

true

primary energy system of type 2 vs type 1 fibers

anaerobic vs aerobic

stimulator vs inhibitor

increases vs decreases ATP production (ADP vs ATP)

100% energy at rest comes from…

OxPhos

O2 consumption at rest = relative vO2

3.5 mL/kg/min

vO2

volume of O2 consumed/min

open circuit spirometry

used to measure vO2

equation for vO2

volume of O2 inspired - expired

oxygen deficit

lag in O2 uptake, reach steady state in 1-4 mins, switch from PC→aerobic

vO2 max

aerobic capacity

lower O2 deficit in untrained people means…

reach steady state faster = less lactate + H+

bioenergetics: 1-5 sec exercise

ATP PC

bioenergetics: >5 sec exercise

fast glycolysis (lactate)

bioenergetics: >45 sec exercise

slow glycolysis (pyruvate)

bioenergetics: >10 min exercise

OxPhos

prolonged exercise in hot/humid environment causes…

upward drift in vO2 max

gradual increase in work rate over time increases ____

O2 uptake

physiological ceiling is affected by…

genetics and training

lactate threshold

where blood lactate levels rise, higher in trained individuals

explanations for LT: low muscle oxygen

hypoxia → more anaerobic metabolism

explanations for LT: accelerated glycolysis

excess NADH converted to lactate

explanations for LT: recruitment of fast-twitch fibers

more intensity = more fast fibers = more lactate

explanations for LT: lactate flux

reduced rate of lactate removal from blood

LT predicts ______

sports performance

does lactate cause muscle soreness?

no

optimal intensity for lactate removal

30-40% vO2 max

rapid EPOC

20%, first 2-3 mins after ex, replace O2 + restore PC + ATP

slow EPOC

80%, last 30 mins after ex, lactate → glucose

how long it takes to get back to baseline is based on _____

intensity of exercise

why does intensity affect EPOC?

higher body temp, more O2 needed

factors governing fuel selection

diet, training level, intenstity

why is more O2 used + CO2 produced in fats than CHO?

fats made of less O2

respiratory exchange ratio (RER/R)

ratio of vCO2/vO2

R for fat vs CHO

0.70 vs 1.00

for R to be used as an estimate, a person must be in ______

steady state

50% fat: 50% CHO R value

0.85

primary source of fuel in low vs high intensity exercise

fats vs CHO

crossover concept

movement from burning fat → CHO @ 0.85 R

why does the crossover concept happen?

recruitment of fast muscle fibers (more glycolytic enzymes) + increasing epinephrine

primary source of fuel in low vs high duration exercise

CHO vs fats

sources of CHO during exercise + when is it primary?

glycogen, beginning of high intensity
blood glucose, intermediate intensity

sources of fat during exercise + when is it primary?

triglycerides, beginning of high intensity (2ndary)
FFA, prolonged low intensity

sources of protein during exercise + when is it primary?

very small role during prolonged exercise

lactate as fuel during exercise can be used by…

skeletal muscle + heart, Cori cycle, lactate shuttle

how can lactate be used by skeletal muscle + heart?

type 2 fibers make it → type 1 fibers use as fuel, heart is an active lactate consumer

how can lactate be used by Cori cycle?

lactate converted to glucose in liver to be used as fuel

how can lactate be used by lacate shuttle?

can be transported to other regions to be used as fuel

system needed to perform long term (>30 min) sustained exercise?

aerobic metabolism

energy needed to run maximal 400 meter race (50-60 sec)

combo but mostly anaerobic