Lecture 8 Flashcards
What does organic compounds store? And in what form?
Free energy
In the form of chemical potential energy
What does a cell degrade with the help of enzymes?
Complex organic molecules that are rich in energy to simpler products with less energy
The most efficient catabolic pathway
Cellular respiration
It is helpful to trace cellular respiration with?
The sugar glucose
Explain cellular respiration
Glucose is oxidized in the presence of oxygen to carbon dioxide and water, with the release of free energy.
The net equation of cellular respiration
C 6 H12 O6 + 6 O2 ——> 6 CO2 + 6 H2O + energy (ATP + heat)
Energy contribution of dietary components
Carbohydrate - 4 kcal/g
Protein - 4 kcal/g
Fat - 9 kcal/g
Alcohol - 7 kcal/g
What needs to be present in order for glucose to be oxidized in a living cell?
O 2
In what form is energy harvested from glucose?
High energy electrons
Electrons release a__________________ at each step, which is captured in the form of__________.
Little energy
ATP
Some energy is released as?
Heat
What do electron transfer reactions help to do?
Release chemical! Energy stored in organic molecules
What happens to a substance: during oxidation?
It loses electrons and hydrogen
Oil ( oxidation is loss)
In what form does substance lose energy?
High energy electrons
What happens to a substance in reduction?
Gains electrons and hydrogen
Rig ( reduction is gain)
What is exergonic?
Electron moves from higher to lower energy state
What happens to glucose and O2 during cellular respiration?
Glucose is oxidized
O2 is reduced
What happens with the oxidation of organic fuel molecules during cell respiration?
- Flow of electrons from glucose to oxygen
- electrons how downhill to more electronegative oxygen
- energy is released
Energy harvest step 1
Glucose is oxidized to co2
NAD+ and FAD are reduced to NADH and FADH2
Energy harvest step 2
NADH and FADH2 are oxidized to NAD+ and FAD
Oxygen is reduced to water
Energy is released and ATP is made
ATP synthesis by oxidative phosphorylation
- Energy is harvested in the form of high energy electrons.
- Most of this energy is conserved in NADH and FADH2.
- This energy is finally released when the high energy electrons are transferred to oxygen.
- Energy harvested from glucose is temporarily stored in ATP; the energy currency of cells.
