energy Flashcards
what is meant by animal tissues are dynamic
constantly broken down and replaced
what do catabolic reactions do
generate energy
what do anabolic reactions do
require energy (ATP) to build something
examples of anabolic reactions
muscle contraction
active ion transport
gene expression
hormone secretion
cell division
adipose reserves
growth
lactation/egg production
what is energy balance
total energy provision = total energy needs
what is a positive energy balance
e provision greater than e needs.
stores energy so anabolism
what is a negative energy balance
e provision less than e needs
mobilise body e reserves so catabolism
process of calculating gross energy in a BOMB calorimeter
sample dried
known quantity of DM combusted in sealed chamber
energy released by oxidation of covalent bonds in warm surrounding water
what is the 4 types of energy
gross
digestible
metabolisable
net
what is the percentage of faecal loss
10-70
what is metabolisable energy
the energy assimilated by the animal and available to fuel metabolism
what are the factors affecting ME
digestibility eg fibre content, food prep treatments
species
diet quality - higher protein intake of carnivores increases urinary excretion of energy rich nitrogenous compounds.
nitrogen balance
feeding levels
heat increment of feeding
prehension and mastication
gut contractions
production and release of digestive enzymes and hormones
catabolism of nutrients within the guts and tissues
absorption of nutrients across the gut wall
specific dynamic action of feeding
Net energy
the amount of energy assimilated by the animal & available to fuel metabolic processes other than
those associated with the acquisition of nutrients
what do energy needs vary with
age
species
body size
production level
work
Ta
disease
what is metabolic rate
total conversion of energy in the body per unit time
what is the basal metabolic rate
amount of energy expended just to keep you alive
how to measure the basal metabolic rate
not moving
not stressed
with TMZ
post absorptive state
how to measure metabolic rate
direct calorimetry - heat production within the animal
indirect calorimetry - heat produced from respiratory exchanges in a calorimeter
what is maintenance metabolic rate
when animal eats exactly the amounts of food needed to maintain a constant body mass
why do younger animals have a greater metabolic rate than older animals
more active - play and exploration
repair and remodelling of tissues
