Energy Flashcards
How do you measure energy?
-by calorimetry
-measurement of heat production
Who were the OG of calorimetry?
-Lavoisier
-Lapalce
What was the experiment that Lavoisier and Lapalce did?
-put guinea pig in a chamber
-measured using melting ice
-related heat production to respiration
-measured water that dripped off ice; proportional to guinea pig
What did Lavoisier discover?
-one of the discoverers of oxygen and proved the idea that animals combust food
What did the calorimeter and guinea pig demonstrate?
-That the guinea pig and fire both produced same heat per amount of CO2
What was the same as heat produced when an animal metabolized a substance?
-heat produced when it was burn
What is heat?
Energy
What are the laws of thermodynamics?
-First law: energy is neither created nor destroyed (it is transformed). Always the same
-Second law: Energy in its simplest form can be measured as heat
What are the laws of thermodynamics for animal nutrition?
-First law: energy input must equal output plus or minus any change in body energy
-Second law: No transformation of energy is 100% efficient and the inefficiencies are lost as heat
What is metabolism?
Where energy comes from
What do we use energy for?
-Energy for function
-the energy currency of the cell is ATP
How is energy used in functions?
-peptide bods: joining acids to make protein
-De novo fat synthesis: synthesizing fatty acids
-Transport of nutrients: as we saw w/ some instances of absorption like amino acids
-cell Maintenace
How is energy used in the currency of the cell?
-Cells use ATP to carry out these functions
Where does energy come from?
-Energy production
-energy from energy containing nutrients
-energy containing nutrients from feed/food
Where do cells derive ATP from?
-glycolysis: energy from glucose
-beta-oxidation: energy from fatty acids
-TCA cycle: further energy from metabolites of glucose and fatty acids (and amino acids)
-Oxidative phosphorylation: energy from final derivatives
How do feeds provide energy from nutrients?
-chemical energy is stored in feed nutrients
-cells convert the energy in nutrients to ATP
-ATP is used for cell functions
What are the acetyl-CoA inputs of the citric acid cycle?
-from pyruvate
-from ruminal produced acetate
-from acetyl-CoA from fatty acid beta-oxidation
What is produced from the two carbons of acetate attached to CoA?
CO2
Where does the citric acid cycle occur?
mitochondria
What are the outputs of the TCA cycle for each acetyl-CoA?
-3 NADH + H+
-1 FADH2
-1 FADH2
-1 GTP
Where does NADH, FADH2, and GTP go?
-NADH and FADH2 go to the electron transport chain
-GTP is readily convert to ATP
How does the electron transport chain work?
-NADH + H+ FADH2 transfer their electrons to the electron transport chain and then to electron acceptors like oxygen
-proceeding through the chain releases energy to pump protons (H+) creating an electrochemical gradient
-ways to move electrons out
What is oxidative phosphorylation?
-production of ATP via the proton gradient
-ATP synthetase uses the proton gradient energy to convert ADP and Pi to ATP
-ADP to ATP using H ions
What is the net energy system?
-keep tracking of the use and usefulness of feed energy
Can we account for all energy?
Yes, bc energy is not created or destroyed
What does the net energy system account for?
-The net energy system accounts for all the energy btw a feed and use in an animal
What are the 4 components of the net energy system?
- Gross energy
- Digestive energy
- Metabolize energy
- Net energy
What happens at each level in the net energy system?
-at each level we reduce how much energy
How do we report energy?
Calories or Joules
What is a calorie?
-the energy needed to raise the temperature of 1 gram of water through 1 C
What does 1 calorie equal?
-heat to raise 1 gram H2O from 14.5 C to 15.5 C
