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Learn about cellular respiration, the process by which energy-rich molecules are broken down to produce ATP. Understand the role of ATP as the main energy carrier in cells and its importance in various cellular processes. Explore the benefits of ATP and its storage within the cell.
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Definition ...... Respiration occurs in ... 2 types ...... Equation? Equation? Reactants Products Reactants Products Extra Bonus Marks – Interestingly ..... What do you remember?
Learning Outcomes Define cellular respiration Identify the energy source in cells and within a molecule of ATP Understand the link of ATP between catabolic and anabolic reactions Explain the process of phosphrylation Potential for LO3
Cellular Respiration Definition – Biochemical process by which energy-rich substrate molecules (foodstuff) are progressively broken down in enzymatic pathways to form adenosine triphosphate (ATP, high energy compound) Foodstuff is usually glucose. Glucose is broken down in a series of enzyme controlled steps. Hydrogen and high energy electrons are removed by dehydrogenase enzymes and used to yield ATP.
What is ATP? Adenosine Triphosphate is a molecule composed of: • 1 x Adenosine (adenosine) • 3 x inorganicphosphate (Pi) Guess what it would be called with only 2 phosphates? 1 phosphate? Pi Pi Pi Adenosine 3 Inorganic Phosphate Groups Bonds contain energy How could it release energy?
Energy Release & ADP • When the terminal bond is broken energy is released. 1 Free Inorganic Phosphate Molecule Adenosine Diphosphate Adenosine Triphosphate A Pi Pi Pi 2 (di-) Inorganic Phosphate molecules Adenosine Molecule Energy released when bond breaks Inorganic Phosphate molecules 1 phosphate – adenosine monophosphate
Adenosine triphosphate (ATP) Which cells/processes need energy? Carbon dioxide and water ATP Amino acids energy energy CELLULAR RESPIRATION ENERGY TRANSFER SYNTHETIC PATHWAY energy energy Protein Glucose and oxygen ADP +Pi Main energy carrier molecule in the body (and all living things). ATP is used to transfer (links) the energy released (catabolic) from cellular respiration to synthetic pathways (anabolic) and other cellular processes where energy is required
Muscle cell Sperm cell Image source: http://www.agen.ufl.edu Image source:http://www.dkimages.com Liver cell Nerve cell Image source:http://www.sccollege.edu Image source:http://www.dkimages.com Uses of ATP in cells are: • Muscle contraction • Driving chemical reactions • Active transport • Synthesis of e.g. protein • Transmission of nerve impulses
Bioluminescence Demonstration - Luminescence is emission of light by a substance not resulting from heat; it is thus a form of cold body radiation
Fluoro Fish http://lem.ch.unito.it/didattica/infochimica/2008_GFP/Fish.html
ATP 2 million molecules of ATP per second is needed to satisfy energy requirements for an active cell (such as liver/muscle etc)! How and where is it stored?
ATP Glucose (6C) ATP Phosphorylation at step 1 ADP+ Pi ATP & citric acid inhibit phosphofructikinase! So go back to intermediate 2 Other metabolic pathways (eg. stored as glycogen) Intermediate 1 Intermediate 2 ATP Phosphorylation at step 3 catalysed by phosphofructokinase Irreversible step ADP+ Pi Intermediate 3 Citric Acid Cycle & Electron Transport Chain Not stored! Rapid turnover of ATP molecules occurs continuously in a cell. Remains quite constant as the same amount is made that is used up (~50g) Cell conserves resources by only producing ATP when needed – it is another example of feedback inhibition . ATP and citric acid inhibit phosphofructikinase
Phosphorylation ATP Breakdown energy released Build-up energy required ADP +Pi Phosphorylation is process which is enzyme controlled where a phosphate group (Pi) is added to a molecule.
Phosphorylation ATP ADP +Pi Glucose Glucose-6-phosphate (high energy) Not only making ATP is called phophorylation (remember post translational modifiction of proteins), also when Pi from ATP given to another molecule in a metabolic pathway it makes them more reactive. For example glucose in glycolysis ...... The phosphorylation of molecules to alter their reactivity.
Advantages of ATP • Releases energy in small amounts as needed • It is mobile and transports chemical energy to where it is needed IN the cell • Universal energy carrier and can be used in many different chemical reactions • Instant source of energy in the cell
Complete your exit slip before you go • ATP Exit cards • Draw/label ATP • Complete the following equation: • ATP _____ + ________ + _______ • The process name of adding a phosphate? • What happens to the molecules then? • Name 3 process that need ATP;