Metabolism Flashcards
(28 cards)
Which type of energy can be used to do all forms of physiological work?
Chemical Energy
What types of energy can do only SOME physiological work?
What type can’t do any physiological work?
Mechanical and electrical energy can only do SOME physiological work
Heat cannot do any
How does chemical energy enter the body?
Ingestion of food
BUT only some of it is absorbed
In what ways can energy leave the body? How are these lost?
Chemical energy
- fecal mater
- organic matter after death
Mechanical energy
-work done by muscle action
Heat energy
- due to inefficiencies
What is metabolism?
The energy required to perform all the chemical reactions in an animal.
All of the reactions, including those that release energy and use energy
What is anabolism?
The biosynthetic or constructive part of metabolism; those chemical reactions involved in biosynthesis.
Growing & building the body.
Ex. The synthesis of glycogen from glucose
What is catabolism?
In a cell, those metabolic reactions that result in the breakdown of complex molecules into simpler compounds, often with the release of energy.
Ex. Breaking down
The process of digesting food.
During aerobic metabolism, how much energy is produced to make ATP and how much is released as heat?
40% ATP
60% heat
- heat is always the dominant component of metabolic rate
What is metabolic rate?
The rate at which an animal converts chemical energy to heat + external work
NOTE: energy of external work also usually ends up as heat
What does an animal’s metabolic rate tell us?
How much food an animal needs
Quantitative measures of the total activity of all its physiological mechanisms.
(its intensity of living)
Measures the drain the animal places on the physiologically useful energy supplies of its ecosystem
What are the direct and indirect measures of metabolic rate?
Direct:
Heat
Indirect:
Food Intake
O2 Consumption
CO2 Production
What is the most common form of measuring metabolic rate?
Respirometry
What is the Material Balance Method?
Measuring the chemical energy content of organic matter that enters and leave the body
Subtract energy in excretion from the energy in the intake and you can estimate the animal’s metabolic rate
Mostly used in agricultural production research
What is respirometry?
The measure of gas exchange of an organism with its environment.
Either O2 consumption or CO2 production
What would make measuring an animal’s metabolic rate inaccurate?
Gaining / Losing weight
Shedding fur / feathers
What produces the most heat per O2 consumption? Lowest?
Carbohydrates are the most.
Proteins are the least
What produces the most heat per CO2 consumption? Lowest?
Lipids are the most.
Carbohydrates are the least
Why can’t metabolic rate calculations be exactly accurate?
Because food is made up of different specific mixtures of carbs, lipids, and proteins, and each of those cause heat production to vary.
What factors have large effects on an animal’s metabolic rate?
Physical activity levels
Environmental temperature
What factors have small effects on an animal’s metabolic rate?
Ingestion of a meal Body size Age Gender Environmental O2 Levels Hormonal status Time of day
What is specific dynamic action?
This is when an animal’s metabolic rate goes up for a while after it has eaten when it has not eaten for a while, even if everything else is kept constant.
What is the thermal neutral zone?
The range of environmental temperatures in which homeopathic species have a minimal metabolic rate.
What is basal metabolic rate and when does it occur?
This is the lowest metabolic rate for an endotherm.
This occurs when the animal is in the thermoneutral zone, is fasting, and is resting.
What is the difference between the lower critical temperature and the upper critical temperature?
These are the bounds of the thermoneutral zone.
Beyond the lower critical temperature MR is increased due to shivering.
Beyond the upper critical temperature MR is increased due to active heat loss.
