Ch. 7 Flashcards
Define metabolism
The set of life-sustaining chemical reactions in organisms
Define metabolic rate
An animal’s rate at which it converts chemical-bond energy to heat and external work
Define closed system
Physical system that doesn’t allow transfer of matter in or out of the system, although the transfer of energy is allowed
Define open system
Physical system that does allow the transfer of matter in and out of the system, including the transfer of energy
Define chemical energy
Energy that is liberated or required when atoms are rearranged into new configurations - in animals, food
Define electrical energy
Energy that a system possesses by virtue of the separation of positive and negative electrical charges
Define mechanical energy
Energy of organized motion in which many molecules move simultaneously in the same direction
Define absorbed energy
Energy of compounds that an animal absorbs from its digestive tract
Define work
Energy transferred from one system to another
Define basal metabolic rate
Metabolic rate of a warm-blooded animal when it is resting and fasting
Define standard metabolic rate
Metabolic rate of a cold-blooded animal when it is resting and fasting
Define weight-specific metabolic rate
An animal’s metabolic rate per unit of weight
Define metabolic scaling
Relationship that exists between metabolic rate and body weight within sets of related species (i.e., small animal with higher metabolism vs large animal with lower metabolism)
Define allometry
Scaling of body functions and features with size
Define specific dynamic action
A rise in the metabolic rate of an animal caused by the processing of ingested food
The second law of thermodynamics states that _____________________.
the total entropy of a closed system can never decrease over time
Low randomness and disorder are related to ________ entropy.
low
High randomness and disorder are related to ________ entropy.
high
Closed systems spontaneously evolve towards ___________________, then returns to ________________.
thermodynamic equilibrium; disorder
Define energy
Capacity to do work
What’s the difference between heat and temperature?
Heat: level of energy within an object
Temperature: overall vibration of molecules within an object
Define potential energy
The energy that is stored in an object due to its position relative to some zero position
Define kinetic energy
Energy of motion
What is the most common energy input in animals?
Ingested chemical energy (Food)
Define energy inefficiency
Energy loss from factors such as imperfect reactions, bouncing molecules, and a trend to disorganization
Define calorie
Unit of energy determining how much energy can be extracted from food
Describe Lavoisier’s direct calorimeter
A small animal was kept in a metal container covered in two layers of ice. Released heat by the animal melts the inner layer of ice, dripping down to the bottom bowl to be measured.
As the metabolic rate increases, released energy (heat) ________________.
increases
How is energy inefficiency indirectly measured?
Respiration; the heat offset based off the breakdown of glucose is known
List the foodstuff in order of energy required to process, most to least.
Lipids
Proteins
Carbohydrates
How do you measure net growth efficiency?
NGE = (energy added to tissue) / (absorbed energy)
Metabolic rate equation
M = aW^b
Weight-specific metabolic rate equation
M/W = aW^(b-1)
_____-blooded animals require more energy
Warm
_____-blooded animals require less energy
Cold
High SA:Vol leads to high _____________ and low ____________.
metabolic rate; waste/material exchange
