ATP What Is ATP? Energy used by all Cells Adenosine Triphosphate

Chemical Structure of ATP Adenine Base 3 Phosphates Ribose Sugar

What Does ATP Do for You? It supplies YOU with ENERGY!

How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP

The ADP-ATP Cycle ATP ADP

https://www.youtube.com/watch?v=V_xZuCPIHvk (ATP Song) Copyright Cmassengale

Photosynthesis and Cellular Respiration

Photosynthesis Method of converting sun energy into chemical energy usable by cells Autotrophs: self feeders, organisms capable of making their own food Photoautotrophs: use sun energy e.g. plants photosynthesis-makes organic compounds (glucose) from light Chemoautotrophs: use chemical energy e.g. bacteria that use sulfide or methane chemosynthesis-makes organic compounds from chemical energy contained in sulfide or methane

Photosynthesis Photosynthesis takes place in specialized structures inside plant cells called chloroplasts Light absorbing pigment molecules e.g. chlorophyll

Overall Reaction 6CO2 + 12 H2O + light → C6H12O6 + 6O2 energy C6H12O6 = glucose CO2 = Carbon Dioxide

Light-dependent Reactions Overview: light energy is absorbed by chlorophyll molecules-this light energy excites electrons and boosts them to higher energy levels. They are trapped by electron acceptor molecules that are poised at the start of a neighboring transport system. The electrons “fall” to a lower energy state, releasing energy that is harnessed to make ATP

Energy Shuttling Recall ATP: cellular energy-nucleotide based molecule with 3 phosphate groups bonded to it, when removing the third phosphate group, lots of energy liberated= superb molecule for shuttling energy around within cells. Other energy shuttles-coenzymes (nucleotide based molecules): move electrons and protons around within the cell NADP+, NADPH NAD+, NADP FAD, FADH2

Light-dependent Reactions Photosystem: light capturing unit, contains chlorophyll, the light capturing pigment Electron transport system: sequence of electron carrier molecules that shuttle electrons, energy released to make ATP Electrons in chlorophyll must be replaced so that cycle may continue-these electrons come from water molecules, Oxygen is liberated from the light reactions Light reactions yield ATP and NADPH used to fuel the reactions of the Calvin cycle (light independent or dark reactions)

Calvin Cycle (light independent or “dark” reactions) ATP and NADPH generated in light reactions used to fuel the reactions which take CO2 and break it apart, then reassemble the carbons into glucose. Called carbon fixation: taking carbon from an inorganic molecule (atmospheric CO2) and making an organic molecule out of it (glucose)

https://www. youtube. com/watch https://www.youtube.com/watch?v=sQK3Yr4Sc_k (Crash Course – Photosynthesis) https://www.youtube.com/watch?v=ww33L0lD37I (Photosynthesis Song)

Harvesting Chemical Energy Plants and animals both use products of photosynthesis (glucose) for metabolic fuel Heterotrophs: must take in energy from outside sources, cannot make their own e.g. animals When we take in glucose (or other carbs), proteins, and fats-these foods don’t come to us the way our cells can use them

Cellular Respiration Overview Transformation of chemical energy in food into chemical energy cells can use: ATP These reactions proceed the same way in plants and animals. Process is called cellular respiration Overall Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (36 ATP)

Cellular Respiration Overview Breakdown of glucose begins in the cytoplasm: the liquid matrix inside the cell At this point life diverges into two forms and two pathways Anaerobic cellular respiration (aka fermentation) = no oxygen Aerobic cellular respiration = uses oxygen

C.R. Reactions Glycolosis Series of reactions which break the 6-carbon glucose molecule down into two 3-carbon molecules called pyruvate Process is an ancient one-all organisms from simple bacteria to humans perform it the same way Yields 2 ATP molecules for every one glucose molecule broken down Yields 2 NADH per glucose molecule

Anaerobic Cellular Respiration Some organisms thrive in environments with little or no oxygen Marshes, bogs, gut of animals, sewage treatment ponds No oxygen used= ‘an’aerobic Results in no more ATP, final steps in these pathways serve ONLY to regenerate NAD+ so it can return to pick up more electrons and hydrogens in glycolysis. End products such as ethanol and CO2 (single cell fungi (yeast) in beer/bread) or lactic acid (muscle cells)

Aerobic Cellular Respiration Oxygen required = aerobic 2 more sets of reactions which occur in a specialized structure within the cell called the mitochondria 2. Kreb’s Cycle 3. Electron Transport Chain

Kreb’s Cycle Completes the breakdown of glucose Takes the pyruvate (3-carbons) and breaks it down, the carbon and oxygen atoms end up in CO2 and H2O Hydrogens and electrons are stripped and loaded onto NAD+ and FAD to produce NADH and FADH2 Production of only 2 more ATP but loads up the coenzymes with H+ and electrons which move to the 3rd stage

Electron Transport Chain Electron carriers loaded with electrons and protons from the Kreb’s cycle move to this chain-like a series of steps (staircase). As electrons drop down stairs, energy released to form a total of ATP Oxygen waits at bottom of staircase, picks up electrons and protons and in doing so becomes water

Energy Tally 36 ATP for aerobic vs. 2 ATP for anaerobic Glycolosis 2 ATP Kreb’s 2 ATP Electron Transport 32 ATP 36 ATP Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

https://www. youtube. com/watch https://www.youtube.com/watch?v=1TGg6KyOwc0 (Cellular Respiration Song)

Crash Course https://www.youtube.com/watch?v=00jbG_cfGuQ Amoeba Sisters https://www.youtube.com/watch?v=4Eo7JtRA7lg https://www.youtube.com/watch?v=uixA8ZXx0KU