NBIC57 metabolism edno & ecto

Direct and indirect calorimetry as methods to determine metabolic rate. In which units is metabolic rate measured?

Direct: Rate that heat leaves body. Simple way is measuring how much ice an animal melts in an enclosure if heat production per gram of ice is known. Cons: Has to consider external work that also requires energy.

Indirect, 2 methods: 
-rate respiratory exchange with environment: is a fixed amount but oxidization of different foodstuff has different heat production → conversation factor.
-material balance: chemical energy of contents leaving and entering a body.

Units: J/ml O₂ or joule/ calories etc

What is the respiratory quotient (RQ)? How do you calculate it?

Different foodstuff yield different quantaties of heat per unit of O₂ consumed which RQ takes account for. It is ratio between CO₂ production and O₂ consumption to know which foodstuff.

RQ = [CO₂]/[O₂]
RQ= 1 → carbonhydrates
RQ= 0,7 → prolly lipids, since they need more O₂ to burn

BMR vs SMR

BMR = basal metabolic rate: standarized measure for endothermes. In thermoneautral zone, fasting and resting.

SMR = Standard metabolic rate: when ectotherms is fasting and resting at a given body temparature

Why is weight-specific BMR dependent on body size? How does an allometric equation look like?

Scientist speculate that it’s bc of the different area to volume ratio where smaller animals have higher ratio → more area for heatloss → higher metabolic rate. This is an allometric realtion where metabolism changes with body size.
M = aW^b b=/= 1

What happens if the ETC is uncoupled?

An uncoupling protein produces heat while pumping/diffusing H⁺ back to innermembrane instead of ATP. This is present when extr heat is needed when for example hibernating or for newborns.

What is the main phosphagen and how is it used?

Vertebrates- creatine phosphate, Invertebrates- arginine phosphate. These extra phosphate bond which can be donated to ADP to create ATP. Used for anaerobic metabolism.

Differences between the different mechanisms of ATP production in vertebrates.

Aerobic catabolism using oxygen from environment is a steady state mechanism and is preferabally used since the source is unlimited, but this is a slower process both in synthesising ATP but also the rate.
Anaerobic mechanisms + using O₂ stores produces ATP fast but at low quantities, hence, non-steady state mechanisms.

Aerobic and anaerobic metabolism during exercise. What is oxygen deficit? What is excess postexercise oxygen consumption?

When exercising there are transition phases.
Oxygen deficit occur in the beginning when theoretical O₂ demand is higher than theactual O₂ intake.
EPOC is when exercise stops and theoretical O₂ demand are lower than actual consumption which gradually declines.

Sources of ATP during exercise.

Varies on intensity and duration

Aerobic Scope and pejus

Aerobic scope is difference between MMR and SMR, only relevant for ectotherms since endotherm’s thermal relations derivates from these rules. How much an animal can increase MR at given temperature. There are absolute and factorial aerobic slope: MMR - SMR, MMR/SMR respective.

Pejus temperature: aerobic scopes shows which temp gives peak performance but temperatuers above this will end up in worse performance. 

Temperature sensitivity. Q10

MR changes exponentially with temperature. Measuring how MR changes over increment of 10^o C. Describes temp. sensitivity.
R_t / R_(T-10) Often between 1-3

How do turtles cope with anoxia?

They go into metabolic depression which reduces 90% of body activity and lowers catabolism. Since this results in anaerobic metabolism lactate accumilates but thos can be buffered by carbonates from shell.

Regulation vs conformity for different parameters: temperature, oxygen, salinity.

Regulators have the same internal temperature as external temp fluctuate while conformers has same as external.

Oxygen conformity changes oxygen needs by changing MR while oxygen regulator has the same oxygen consumption and has active responses to changing O₂ concentration.

!! Osmoregulators has different mechanisms for salt trp or change salt ingested.

Acclimation and acclimatization

Both studies when one gene gives rise to multiple phenotypes

Acclimation: is when one variable is changed and studies, often in lab

Acclimatization: multiple variables influences, in the animals natural habitat

Special anaerobic metabolism in the crucian carp.

Mechanism to survive in ice or where there are less predators.

Anaerobiosis: Lactic acid accumulates but special muscleshas enzymes that catalys this into ethanol which is secreted through gills.

Maximum rate of oxygen consumption. Aerobic capacity. Maximum aerobic power. How to measure it?

VO₂ max is the highest aerobic capacity which is different between and within species. Used for understanding types of species and O₂ consumption capacity.

Unit: ml O₂ /min*kg. 

Hibernation and other strategies to lower the costs of keeping body temperature constant.

Uncoupling in brown fat is a method of keeping constant body temperature when hibernating to reduce costs. Changing MR through hypothermia where the animal lowers body temp to ambient temp. → temporal heterothermes. 

Using periodic arousal to reheat body without ambient heat.

Animals need energy because they are organized and ordered systems. What is physiological work?

Physical and chemical activity to keep the body working and organized. For instance homeostasis and making gradients that drives processes.

Costs of biosynthetic processes, maintenance processes and external work.

Biosynthetic: synthesizing molecules, cells & tissue or organic compounds that exports out of body, ex hair or mucus. Cost energy & creates heat.

Maintenance: circulation, respiratory, nervesystem, gut mobility ets. Energy demanding & generates heat.

External work: Forces an external energy can be stored as energy och produce heat…

Where is oxygen needed in the breakdown of a glucose molecule?

In the ETC creating water to make H⁺ gardient to reoxidize NADH & FADH.

What happens during glycolysis and the Krebs cycle?

Breakdown of glucose and generates ATP

What is the electron-transport chain (ETC) and where is it located?

Located in innermembrane of Mt. Proteincomplexes reoxidies NADH and FADH while simultaneously creating the H⁺ gradient

What is oxidative phosphorylation?

ATPase phosphoralize ADP to ATP.

ATP yield from aerobic processes.

Abt 30 per glucose

End product of anaerobic glycolysis.

Lactic acid/lactate

How does heat exchange take place?

Through conduction, convection, radiation and/or evaporation.