L13. Obtaining Energy from Food Flashcards
direct burning in a nonliving system vs stepwise oxidation - direct burning
- large activation energy is overcome by the heat from a fire
- all the free energy is released as heat (none is stored)
direct burning in a nonliving system vs stepwise oxidation - stepwise oxidation
- also cellular respiration
- small activation energies are overcome by enzymes that work at body temperature
- some of the free energy is stored in activated carrier molecules
how are the activated carriers ATP and NADH are used
- the energy from food breakdown (oxidation and favorable) is transferred to ATP and NADH
- the energy from ATP is then coupled with ATP synthesis
- energy from other carriers drive oxidative phosphorylation
what is oxidative phophorylation
- takes place in inner mitochondrial membrane
- it is when the cell uses energy from activated carriers to drive ATP production
what are the three stages to breaking down food molecules
- mouth, gut, and lysozymes
- cytosol
- mitochondria
three stages to breaking down food molecules - mouth, gut, and lysozymes
large macromolecules are digested and converted into simple monomers via enzymes
three stages to breaking down food molecules - cytosol
- glucose enters via glucose/Na+ symporter
- gradual oxidation breakdown of simple monomers via glycolysis
- glycolysis takes 1 glucose and converts it into 2 pyruvates
- also produces ATP and NADH
three stages to breaking down food molecules - mitochondria
- pyruvate enters the mitochondria matrix and is converted into Acetyl CoA
- acetyl CoA then goes into the citric acid cycle and this makes a large amount of NADH
- electrons from NADH is passed to the electron transport chain
- this causes oxidative phosphorylation to begin, producing a large amount of ATP
explain the location of the reactions for aerobic respiration
- glycolysis: cytosol
- citric acid cycle and oxidative phosphorylation: mitochondria
three stages to breaking down food molecules: cytosol - explain ATP and NADH in glycolysis
- 2 ATP is required and produces 4 ATP with a net ATP of 2
- also produces 2 NADH
three stages to breaking down food molecules: cytosol - glycolysis in absence of O2
products are ethanol or lactic acid fermentation
three stages to breaking down food molecules: cytosol - glycolysis in presence of O2
pyruvate goes to mitochondria
three stages to breaking down food molecules: cytosol - how does glycolysis initiate the breakdown of sugars
- the breakdown of glucose provides energy for ATP synthesis from ADP and Pi
- during ATP synthesis, substrate-level phosphorylation occurs
- NADH electron is then donated to the electron transport chain (for aerobic organisms)
three stages to breaking down food molecules: cytosol - substrate level phosphorylation
Pi is transferred from substrate molecules (sugar intermediates) to ADP
three stages to breaking down food molecules: cytosol - explain NAD+
- an intermediate in catabolic reactions that generate ATP through the oxidation of food molecules
- it is an oxidizing agent (takes e-)
- kept high in the cell