Principals Pf Physiology: Chapter 7 - Energy Metabolism

Front 1

Animals use energy for:

There are three things.

Back 1

- Biosynthesis
- Maintenance
- Generation of external work

Front 2

List and define the two general types of metabolic pathways.

Back 2

- Anabolic pathways
* Simple substances > complex molecules
* Requires energy

- Catabolic pathways
* Complex molecules > simpler substances
* Releases energy

Front 3

Name the three types of substances used for energy storage.

List the hierarchy of which is best to use. State why.

Back 3

1) Carbohydrates
* Rapidly converted to G6P
* Is a more direct source of energy than fat

2) Fat
* Cannot be metabolized anaerobically

3) Protein
* Nitrogen is valuable, so it is rarely used

Front 4

Define "SMR"

Back 4

SMR = Standard metabolic rate

- Resting and fasting metabolism at a given temperature

Front 5

BMR

Back 5

BMR = Basal metabolic rate

Resting and fasting metabolism for a thermoneutral endotherm

Front 6

RMR

Back 6

RMR = Resting metabolic rate

Metabolism of an inactive animal (fed, and thermoregulating)

Front 7

MMR

Back 7

MMR - Maximum metabolic rate

A ratio of maximum metabolic rate in relation to SMR or RMR.

Front 8

FMR

Back 8

FMR = Field metabolic rate

Average rate of energy use for an animal over a given period of time.

Front 9

In what three ways is MR measured?

Back 9

- Indirect calorimetry
* measures heat loss (ice chamber)
* bomb calorimetry (delta energy in / out)
* Doubly-labeled water

- Direct calorimeotry/respirometry
* Measures O2 consumption or CO2 exhaled

Front 10

Assumptions based on indirect calorimetry

Back 10

- Metabolic reactions are aerobic
- O2 consumption and CO2 exhaled are equal
- CO2 is 100% exhaled from the body
- Heat loss is the same between all metabolic reactions

- Animal uses 100% of available energy within consumed food

Front 11

Respiratory quotient, RQ.

* Equation
* Definition

Back 11

- RQ, respiratory quotient
* represents overall metabolism

* (rate of CO2 production) / (rate of O2 production)

Front 12

Respiratory exchange ratio, RE.

Back 12

* RE, Respiratory exchange ratio
- Instantaneous relationship between CO2 and O2

Front 13

Describe the process of using radioisotopes to measure MR. Is this a form of direct or indirect calorimetry?

Back 13

Injecting Doubly labeled water (indirect calorimetry)

1) Inject doubly labeled water (O18 and H2 or H3 isotopes).
2) Allow a period of time for the body to integrate/use/process the doubly labeled water.
3) Measure isotope levels within the blood.
* Measured O18 isotope gives rate of CO2 and H2O loss.
* Measured H2 or H3 isotopes gives rate of H2O loss.
* Difference between both give rate of CO2 loss.

Front 14

What is the mass-specific unit?

Back 14

mL of O2 / (g * unit time)

Front 15

What are the environmental consequences of metabolic rate with respect to body size?

Back 15

1) Smaller animals favor food with high energy content.

2) Larger animals eat as much food as they can without regard to energy content.

Front 16

List the RQ values for:
- Carbohydrates
- Lipids
- Protein

Back 16

RQ values for:

- Carbohydrates = 1
- Lipids & Fats = 0.7
- Proteins = 0.8