ATP Formation, Photosynthesis, and Cellular Respiration
ATP SynthaseWe Need Energy!!!All living things need energy. All cells need to produce that energy in order to power cellular activities (reactions)Adenosine TriphosphateATP is an energy-storing molecule that is needed to power many cellular activitiesIt is made up of a base adenine, a sugar ribose, and 3 phosphate groups
ATP FormationProtons move down the electrochemical gradient (from high concentration to low concentration)
Energy from the Hydrogen ions is transferred to ATP Synthase (the protein used in ATP formation) that energy is used to add a phosphate group to ADP (adenosine diphosphate) creating ATP (adenosine triphosphate) the high energy is stored in the bond between the last two phosphate groupsATP SynthaseATP FormationATP molecules then go on to power cellular activities By breaking the bond between the last 2 phosphate groups the high energy that was stored is then released
Powers Cellular ActivitiesATP FormationLocation:
ATP Synthesis happens in the chloroplast and mitochondria
In the chloroplast most ATP is synthesized across the thylakoid membraneIn the mitochondria most ATP is synthesized across the inner membrane of the mitochondriaPhotosynthesis:Converting Solar Energy into a usable form.
6H2O + 6CO2 C6H12O6 + 6O2In plants, energy made in photosynthesis is stored as sugar. Energy required for metabolic activities and making other molecules.Ex. Plants, algae, and certain bacteria (aka: producers)
Plants are autotrophs because they produce their own food (energy)
Plants sometimes make more sugar than they can use at one time. They will convert this sugar to starch for short and long term storage
CyanobacteriaPlants serve as food for animalsCrop a type of plant that is cultivated for use by humans Ex. Corn, tomatoes, peas, wheat, etc6H2O + 6CO2 C6H12O6 + 6O2
How Photosynthesis WorksPhotosynthesis occurs in chloroplasts which are tiny green organelles found in Eukaryotic plant cells.Thylakoids located inside chloroplasts, are flattened membrane-bound sacs. Stacked like coins or pancakes in columns called grana. Both are suspended in fluid matrix called stroma.
Light is a form of radiant energy energy that is transmitted in wavesElectromagnetic Spectrum complete range of radiant energy (ROYGBIV = visible light)
All forms of radiant energy consists of tiny packets of energy called photons3 things can happen to photons:Reflect bounce offAbsorbTransmit pass through Ex. In leaves red and blue (and all other colors) light are absorbed, but green light which is reflected.
Pigment a molecule containing atoms that enable it to absorb light.Ex. Chlorophyll (located in chloroplasts) green pigment found in photosynthesis Ex. Carotenoids pigment that produces a yellow/orange color.
CarotenoidsPhotosynthesis:Light-Dependent Reactions & Carbon Fixation (Calvin Cycle)Photosynthesis: General OverviewLight-Dependent ReactionsCarbon Fixation(Calvin Cycle)H2OLightC6H12O6O2ATP and NADPHCO2Light Dependent Reactions
Video ClipCarbon Fixation (Calvin Cycle)
Cellular Respiration: Glycolysis, Krebs Cycle, and the Electron Transport Chain
Cellular Respiration Overall ReactionC6H12O6 + 6O2 6CO2 + 6H2O + energy
This equation is a simplified representation of cellular respiration. Actually, cellular respiration is a complex metabolic pathway, comprising at least 30 separate steps. To understand respiration in detail we can break it up into 3 stages.
3 Stages of Cellular Respiration
Net ATP:2 ATP32 ATP2 ATPThe different stages of respiration take place in different parts of the cell. This allows the cell to keep the various metabolites separate, and to control the stages more easily.
Points from the 3 stages diagram:The energy released by respiration is in the form of ATP (Adenosine Triphosphate)The release of carbon dioxide takes place before oxygen is involved. It is therefore not true to say that respiration turns oxygen into carbon dioxide; it is more correct to say that respiration turns glucose into carbon dioxide, and oxygen into waterStage 1 (glycolysis) is anaerobic respiration, while stages 2 and 3 are the aerobic stages.
Cellular RespirationIncludes pathways that require oxygenGlucose is oxidized and O2 is reducedGlucose breakdown is therefore an oxidation-reduction reactionBreakdown of one glucose results in roughly 36 to 38 ATP molecules An Oxidation-Reduction Process or REDOX ReactionOxidation of GLUCOSE --> CO2 + H2O (e- removed from C6H12O6)Reduction O2 to H2O (e- passed to O2)What Type of Process is Cellular Respiration?Metabolic Pathway that breaks down carbohydratesProcess is Exergonic as High-energy Glucose is broken into CO2 and H2OProcess is also Catabolic because larger Glucose breaks into smaller moleculesOther Cellular Respiration Facts
Mitochondria The Power House
Much of respiration takes place in the mitochondria. Mitochondria have a double membrane: the outer membrane contains many protein channels called porins, which let almost any small molecule through the inner membrane is more normal and is impermeable to most materials. The inner membrane is highly folded into folds called christae, giving a larger surface area. The electron microscope reveals blobs on the inner membrane, which were originally called stalked particles. These have now been identified as the enzyme complex that synthesises ATP, are is more correctly called ATP synthase. The space inside the inner membrane is called the matrix, and is where the Krebs cycle takes place. The matrix also contains DNA and some genes are replicated and expressed here.Mitochondrial DNA get only from Mom (exactly the same as mom)Nuclear DNA get from Mom & from Dad
Aerobic and Anaerobic Respiration
The first part of respiration is simply the breakdown of Glucose (6C) to a compound called Pyruvate (3C)
This doesnt require oxygen, so is described as anaerobic respiration (without air). It is also called glycolysis and it takes place in the cytoplasm of cells. It only produces 2 molecules of ATP per molecule of glucose.
Normally pyruvate goes straight on to the aerobic part, but if there is no oxygen it is converted to lactate (or lactic acid) instead. Lactate stores a lot of energy, but it isnt wasted : when oxygen is available it is converted back to pyruvate, which is then used in the aerobic part of respiration.
Aerobic and Anaerobic Respiration The second part of respiration is the complete oxidation of pyruvate to carbon dioxide and H2O. Oxygen is needed for this, so it is described as aerobic respiration (with air). It takes place in the mitochondria of cells and produces far more ATP: 34 molecules of ATP per molecule of glucose. Fats (mainly triglycerides) can also be used in aerobic respiration (but not anaerobic) to produce ATPTotal ATP from Cellular Respiration = 36 ATP molecules
A Little Krebs Cycle HistoryDiscovered by Hans Krebs in 1937He received the Nobel Prize in physiology or medicine in 1953 for his discoveryForced to leave Germany prior to WWII because he was Jewish