Unformatted text preview:

*Note-if there are no notes for a slide, it just means the book didnʼt have any extra information that wasnʼt on the slide or that the slide if pretty self-explanatory orLecture 10 Notes:•Slide 1•Slide 2•How the cell converts external energy sources, such as chemical nutrients or sunlight, into a intracellular chemical energy carrier--Adenosine Triphosphate (ATP)•ATP is found in all types of organisms; it is generated from ADP and inorganic phosphate (HPO42- or Pi)•Cells use the energy released during hydrolysis (http://faculty.ccbcmd.edu/biotutorials/energy/adpan.html) of the high-energy phosphoanhydride bond in ATP to power many otherwise energetically unfavorable processes•Slide 3•Energy to drive ATP synthesis from ADP is produced primarily by two processes: Aerobic Oxidation occurring in the Mitochondria in all eukaryotic cells and photosynthesis which occurs in chloroplasts on in leaf cells of plants and certain single celled organisms•Two additional processes, glycolysis and the citric acid cycle, are also important sources of ATP•Slide 4•energy stored in the covalent C bonds will be utilized by the cell•most of energy is stored in carbohydrates; the cell efficiently degrades the 6-carbon molecule; the covalent C bond will undergo oxidative phosphorylation to produce CO2•Slide 5•Slide 6•Substrate level phosphorylation--glycolysis--occurs in the cytoplasm•Substrate-level phosphorylation- is a type of metabolism that results in the formation and creation of adenosine triphosphate (ATP) or guanosine triphosphate (GTP) by the direct transfer and donation of a phosphate(PO3) group to adenosine diphosphate (ADP) or guanosine diphosphate (GDP) from a phosphorylated reactive intermediate•Slide 7•Oxidative Phosphorylation- is a metabolic pathway that uses energy released by the oxidation of nutrients to produce ATP•During oxidative phosphorylation, electrons are transferred from electron donors to electron acceptors such as oxygen, in redox reactions, These redox reactions release "energy, which is used to form ATP. In eukaryotes, these redox reactions are carried out by a series of protein complexes within mitochondria.•A proton electrochemical gradient is generated across a membrane, driven by energy released as electrons travel through an electron transport chain•The energy store in this gradient, called the proton-motive force, is used directly to power the synthesis of ATP and other energy-requiring processes.•Slide 8•stage 1--glycolysis; in the cytoplasm•we divide them into 4 stages, this all just happens continuously, we just break it up into stages to make it clearer•this slide set focuses on Stage 1•plants have chloroplasts that can synthesize carbohydrates by harvesting sunlight energy that fix CO2 into carbs like glucose (6 C molecules); kind of like reverse of what happens in mitochondria, harvest CO2 and fix it to carbs•Top half of Diagram:•In aerobic oxidation, “fuel” molecules (primarily sugars and fatty acids) undergo preliminary processing in the cytosol, breakdown of glucose to pyruvate "(stage 1), and are then transferred into mitochondria, where they are converted by oxidation with O2 to CO2 and water (stages 2 &3) and ATP is generated (stage 4).•Glucose Oxidation:•Stage I- Conversion in the cytosol of one 6-Carbon glucose molecules to two 3-Carbon pyruvate molecules (glycolysis)•Stage II- Pyruvate oxidation to CO2 in the mitochondrion via 2-Carbon acetyl CoA intermediate (citric acid cycle)•Stage III- Electron transport to generate a proton motive force•Stage IV- ATP synthesis in the mitochondrion (oxidative phosphorylation)•Slide 9•-uni-direction; irreversible; can’t go back to original molecule •KINASE- alternatively known as a phosphotransferase, is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP,[2] to specific "substrates.•3 steps are irreversible; and the others are reversible•donʼt have to know every single step and memorize•steps 1,3, 10 are irreversible, involve kinases, and are critical--know these!•Glycolysis:•Does not require oxygen; called anaerobic glucose catabolism (biological breakdown of complex to simpler substances)•During glycolysis, cytosolic enzymes convert glucose to pyruvate•A set of 10 water soluble cytosolic enzymes catalyze the reactions constituting the glycolytic pathway (think glyco, ʻsweetʼ; lysis, ʻsplitʼ) in which one molecule of glucose is split into two molecules of pyruvate•In addition to producing 2 pyruvates and intermediates, these enzymatic reactions generate 4 ATP molecules by phosphorylation of 4 ADPʼs (steps 7&10) , a process called "substrate level phosphorylation (to distinguish it from the oxidative phosphorylation that generates ATP in the 3rd stage of aerobic oxidation)•Figure:•Glucose is degraded to pyruvate. 2 reactions consume ATP, forming ADP and phosphorylated sugars (red), two generate ATP from ADP by substrate level phosphorylation (green), "and one yields NADH by reduction of NAD+ (yellow). Note that all the intermediates between glucose and pyruvate are phosphorylated compounds. Reactions 1,3, and 10, with single arrows, areessentially irreversible (large negative delta G value) under ordinary cell conditions.•Slide 10•This is the balanced chemical equation for the conversion of glucose to pyruvate•produces net gain of 2 atp molecules; most of the energy is stored in the electrons•Glycolysis of 1 molecule of glucose gives a net gain of 2 atp molecules; energy production by glycolysis is essentially a minimum; cell cannot harvest in glycolysis in the cytosol•after oxidative phosphorylation, you have 30 atp molecules•Slide 11•Electron carriers •NADH carriers two electrons•Remember LEO goes GER! (Lose Electrons-Oxidized; Gain Electrons-Reduced)•2NADH are produced after glycolysis; this is a bigger molecule and is less easily transported across the membrane; needs carrier proteins--will discuss later•FADH--can be utilized as the e- carrier; has reducing power-can carry e-ʼs•Slide 12•E stored in the C covalent bond; after glycolysis, produces 2 molecules of atp; most energy produced by glycolysis is carried in the e-’s; which are transported to the inner membrane of the mitochondria•Proton Motive Force:•Transmembrane concentration and electrical (voltage) gradients, collectively called the proton-motive force, are generated


View Full Document

FSU PCB 3134 - Compiled Notes

Download Compiled Notes
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Compiled Notes and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Compiled Notes 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?