Introduction to Cell Respiration Energy and redox reactions.
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Transcript of Introduction to Cell Respiration Energy and redox reactions.
Introduction to Cell Respiration
Energy and redox reactions
The Pathway of energy in living organisms
Light energy from the sun
Chemical energy stored in glucose, fats, or carbohydrates
Chemical energy for use in the form of ATP
photosynthesis cellular respiration
All living organisms must perform cellular respiration (plants and animals) to get ATP.
Only photosynthetic organisms like plants or blue-green alga can transform light energy into chemical energy
MMMMM…..
Non-photosynthetic organisms (like humans) must consume glucose, fats, and carbohydrates to obtain the energy to produce ATP
Autotrophs = Organisms that make their own food (usually from photosynthesis).
Heterotrophs = Organisms that can't make their own food so they take in food produced by autotrophs (by eating autotrophs or organisms that eat autotrophs)
Energy flow and chemical recycling in ecosystems
Catabolism
Anabolism
Overview of Cellular Respiration
The energy released from the catabolism of glucose is used to make ATP from ADP
ADP + P + energy
ATP
• A series of reduction-oxidation reactions allow for the slow release of energy in glucose so that it can be harnessed to fuel the production of ATP.
energy
energy energy
Vs.
One large reaction Several smaller reactions
Redox Reactions: LEO the lion goes GER
• Loss of Electrons = Oxidation
• Gain of Electrons = Reduction
• Reduced compounds have higher energy because they gain the energy associated with the electrons they gain
Burning methane: an exergonic reaction
Your turn: Which molecule is reduced and which is oxidized?
CO O H HEnergy
Carbon dioxide Water
2 Hydrogen Formaldehyde
O H HOC
H
H
Reduction(takes energy)
Oxidation(releasesEnergy)
NADH(electron carrier)
Redox reactions transfer electrons and energy from carrier molecules during cellular respiration
NAD+ (oxidized, lower energy)
NADH(reduced, higher energy)
NAD+
GLYCOLYSIS KREBS CYCLEELECTRON TRANSPORT AND OXIDATIVE PHOSPHORYLATION
ATP ATP ATP
KrebsCycle
Glucose
NADH
NADH
NADH FADH2
CO2
CO2
H2O
Electron transport chain...
Py
ruva
te
Cell Respiration is separated into 3 stages
Energy/electrons are transferred from glucose to convert NAD+ to NADH, which is used in the ETC to make ATP
Figure 9.6 An overview of cellular respiration (Layer 1)
Figure 9.6 An overview of cellular respiration (Layer 2)
Figure 9.6 An overview of cellular respiration (Layer 3)
Cellular respiration is carefully regulated:
when ATP is abundant, respiration slows down
when ATP is needed, respiration speeds up