Final Exam Flashcards
What is energy?
an electrical current that gives us the ability to do work.
What 3 sources from foods do we receive energy?
Carbohydrates, fats, and proteins (all 3 are facilitators that generate heat through the TCA cycle when oxidized)
What is net energy?
the energy available to do work
The sun releases ______ which transfer energy to free electrons that hydrolyze _____ in plants and converts it to H2 and 02. Oxygen is released and Hydrogen is used as ______.
photons; water; energy
T or F:
Plants and Animals can capture high energy electrons.
False:
Plants can capture high energy electrons through photosynthesis (animals cannot).
The H2 used as energy can attach to an NAD+ or FAD+ to produce _____ or ______ respectively, which eventually get converted to _____.
NADH or FADH; ATP
How do animals retain their high energy electrons?
Animals eat the plants that contain the high energy electrons and the H2 enters the electron transport train (ETC)
The ETC produces ___ ATP for every NADH and ___ ATP for every FADH.
3; 2
All energy uses what three units?
mass, distance, and time
What is an erg?
the energy required to move 1 gram 1 centimeter in 1 second
What is a Calorie?
the energy required to raise 1 gram of water by 1 degree centigrade (from 14.5 to 15.5 degrees centigrade)
What are the units for Joules?
1kg/1m/1sec
Convert 1 Calorie to Joules and 1 Joule to calories.
1 cal = 4.184 J
1 J = 0.234 cal
State the first law of thermodynamics.
Although energy can be changed from one form to another, it can neither be created nor destroyed.
State the second law of thermodynamics.
In all reactions, entropy will increase until it reaches equilibrium (this occurs faster in a closed system).
Define entropy
equilibrium; the degree of randomness (this value is always negative and does have a maximum limit)
Define enthalpy
heat of combustion; the amount of energy present in a carbohydrate, fat, or protein.
What is the Carbohydrate energy content?
4.1 kcal/g
What is the fat energy content?
9.4 kcal/g
What is the protein energy content?
5.65 kcal/g
Define gross energy.
the uneaten energy found in food (measured by a bomb calorimeter).
T or F:
You can accurately compare diets using gross energy,
Gross energy is not a good way to copare diets because it does not exactly express how much energy is digested.
DE?
Digestible energy (largest source of energy loss in the diet)
What components make up DE?
DE = IE - FE
IE?
Intake energy (measured in kcal/day [kcal/g * g/day])
ME?
Metabolizable energy (made up of unrine UE, gill ZE, and surface energy SE
What components make up ME?
ME=IE-(FE+UE+GE) or ME=DE-(UE+GE)
Why do avian nutritionist use ME to measure DE?
Because it is physically impossible to separate feces from urine in avian species.
GE?
Gaseous energy (energy lost as methane)
The more _____ associated with GE the more energy that is lost; while the more _____ the more energy that is saved.
acetate; proprionate
GE is ___% of the DE in non-ruminants and __to__% of the DE in ruminants.
8%; 22-25%
RE?
Recovered Energy (analogous to net energy); the amount of energy we can use to do work.
What are the 5 components of RE?
TE- tissue energy LE-lactation energy OE-ovuum (egg) energy YE-conceptus energy VE-wool, hair, feathers
HE?
Heat production
What components make up HE?
HE=ME-RE or ME=RE+HE
H_E is the part of HE that is always measured in an animals’s thermal neutral zone.
HeE or BMR-basal metabolic rate
What is an animal’s “thermal neutral zone”?
the temperature at which an animal needs to do no physical, or chemical work in order to regulate its body temperature.
H_E is the part of HE that characterizes the normal, everyday activities of the animal.
HjE or Voluntary activity (examples include eating, drinking, walking, etc.)
H_E is the part of HE that uses energy to synthesize a protein, fatty acid, etc.
HrE or Product formation
H_E is the part of HE involved in digestion and absorption.
HdE
H_E is the part of HE involved in thermal regulation.
HcE
H_E is the part of HE involved in the heat of fermentation.
HfE
H_E is the part of HE involved in waste formation and excretion.
HwE
What energy component is known for being the largest soure of energy loss in animals?
Fecal energy (FE)
__to__% of FE from roughage is lost and __to__% of FE from concentrate is lost in Cattle and Sheep
40-50%; 20-30%
__to__% of FE from concentrate and roughage is lost in Horses.
35-40%
___% of FE from a well-balanced ration is lost in swine.
20%
About __% of FE from a well-balanced ration is lost in humans.
10% (highest digestibility)
HiE?
Heat increment (The increase in heat production after food consumption in an animal in its thermal neutral zone. (associated with digestion, absorption, and excretion)
What components make up HiE? (equation)
HiE=HrE+HdE+HfE+HwE
What percent of DE do HrE +HwE make up?
20-25%
What percent of DE do HdE+HfE make up?
4.3-4.4%
NEg?
Net energy growth
NEm?
Net energy maintenance
What components make up NEm?
NEm=HeE+HjE
The energy recovery of protein is about ___% efficient.
85%
__% of NE is NEm and __% of NE is NEr, and can be used to make combustible products (growth, lactation, pregnancy, conceptus, hair/wool/feathers/eggs)
90%; 10%
What is an endotherm?
warm-blooded animal; animal that generates its own heat by inner body functions
Why is it impossible for animals to grow, be pregnant and/or lactate at the same time?
Because NEr (net energy recovery) is 5% or less of the energy intake of most animals
What are R selected animals?
Those selected for reproduction; they can divide their energy between growth, pregnancy, and lactation
What are K selected animals?
Those that can rarely maintain multiple functions simultaneously.