Cell Energy - Molecules Chapter 8

What you need to know! How the process of chemiosmosis utilizes the electrons from NADH and FADH2 to produce ATP How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2 How chemiosmosis generates ATP in the light reactions

Energy Transfer Molecules ATP: Adenosine Triphosphate Molecule that delivers immediately available energy to run cellular processes (active transport, movement, mitosis, production of proteins etc.) All other food/energy molecules (various lipids, carbs, proteins) are converted into ATP through enzyme machinery in cells/liver All energy consuming processes have an ATPase (enzyme) attached

Energy Transfer Molecules ATP is a nucleic acid, a single nucleotide 3 phosphates Ribose Adenine

Energy Transfer Molecules ATP has energy stored between its three negatively charged phosphates because like charges repel each other Most energy is stored between 2nd and 3rd phosphate 3 different forms of energy levels: AMP: monophosphate ADP: diphosphate ATP: triphosphate

Forming ATP for Energy Supply Rx: ADP + P + energy  ATP Enzyme: ATP synthase Energy necessary comes from photosynthesis or catalysis of high energy molecules (respiration)

Breaking Down ATP for Energy Release Rx: ATP  ADP + P + energy Enzyme: ATPase often attached as a coenzyme to various other enzymes/proteins

ATP Resembles a Rechargeable Battery Endlessly recyclable Limited numbers of ATP/ADP can stop energy pathways Largest amount of ATP is made in mitochondria/chloroplasts some in cytoplasm (glycolysis) All energy molecules can be expressed in ATP (glucose: 38 ATP, sucrose: 75 ATP, triglyceride: 180 ATP; assuming O2 is present)

Energy Availability Molecule availability storage ATP immediately none glucose 1-2 min Blood glucose only glycogen 2-3 min Liver, muscles triglycerides 8-10 min Adipose tissue

NADP/NAD/FAD Nicotinamide Adenine Dinucleotide Phosphate (NADP) Functions as electron acceptor/donor/during photosynthesis and respiration A nucleic acid: dinucleotide Rx: Store Energy NADP + e- + H+  NADPH Rx: Release Energy NADPH  NADP + e- + H+

Redox Reactions Definition: transfer of electrons e- during a chemical Rx Photosynthesis, Respiration and Fermentation are all Redox Rx, meaning one reactant is reduced and one reactant is oxidized

Redox Reactions Oxidation: Gain oxygen and lose e- (add O or lose H) = releases chemically stored energy Reduction: Lose oxygen and gain e- (lose O or add H) converts energy into chemically bound energy Catabolic (respiration): energy rich compounds are oxidized (energy releasing reaction) Anabolic (photosynthesis): energy poor compounds are reduced (energy storing reaction)

Redox Reactions OIL (Oxidation is losing e-) RIG (Reduction is gaining e-)

Redox Reactions Example: Extracting Iron from Iron Ore Fe2O3 + 3(CO)  2Fe + 3(CO2) + energy Which reactant is oxidized? ___________ Which reactant is reduced? ___________

Label Oxidation and Reduction Photosynthesis: Light n(CO2) + n(H2O)  n(C3H6O3) + nO2 Cellular Respiration: C6H12O6 + 6O2  6 CO2 + 6 H2O