Cell Energy Molecules Chapter 8

What you need to know! How the process of chemiosmosis utilizes the electrons from NADH and FADH 2 to produce ATP How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O 2 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 2 nd and 3 rd 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 O 2 is present)

Energy Availability Moleculeavailabilitystorage ATPimmediatelynone glucose1-2 minBlood glucose only glycogen2-3 minLiver, muscles triglycerides8-10 minAdipose 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 Fe 2 O 3 + 3(CO)  2Fe + 3(CO 2 ) + energy Which reactant is oxidized? ___________ Which reactant is reduced? ___________

Label Oxidation and Reduction Photosynthesis: Light n(CO 2 ) + n(H 2 O)  n(C 3 H 6 O 3 ) + nO 2 Cellular Respiration: C 6 H 12 O 6 + 6O 2  6 CO H 2 O