Metabollic Test Part 2
gluconeogenesis
Triglycerides are hydrolysed into glycerol and individual fatty acids, gluconeogenesis happens when glycerol becomes glyceraldehyde 3 phosphate. This substance can enter cellular respiration pathway in stage 1.
B-oxidation
The fatty acids that are split off into triglycerides are split off and catabolized into 2C sections in a process called B-oxidation.
deamination
In order for a protein to be used for energy, it
must first be hydrolysed into amino acids and
then deaminated (removal of NH2 group).
allosteric inhibition of phosphofructokinase
Excess ATP in the cytosol binds to the enzyme phosphofructokinase and acts as an allosteric inhibitor, this inhibition of phosphofructokinase results in slowing or stopping ATP production.
fermentation
This process allows cells to regenerate NAD+ and glycolysis to continue. For some organisms, fermentation is the primary pathway for energy generation and for others it is a pathway used when oxygen is not available in adequate supply.
carbon fixation
Carbon Fixation is the first part of the calvin cycle. Carbon fixation happens when carbon combines with rubisco to form 6-phosphoglycerate.
Describe how alternate forms of energy are used to make ATP (including complex carbohydrates, lipids and proteins)
Disaccharides and polysaccharides are converted into monosaccharides by hydrolysis which then enter glycolysis. Triglycerides go through gluconeogenesis to become glyceraldehyde 3 phosphate and then enter stage 1 of cellular respiration. The fatty acids are split off and catabolized into 2C sections in B- oxidation. The 2C that are cut off become acetyl groups and attach themselves to CoA and enter citric acid cycle. For protein to be used for energy it must be hydrolysed into amino acids and then deaminated which is the removal of a NH2 group. Depending on how many carbons remain, the molecule is transformed appropriately and fed into the cellular respiration cycle.
Explain how the production of ATP is regulated
ATP can’t be stored for too long so there is a feedback mechanism that regulates the production of ATP, excess ATP in the cytosol binds to the enzyme phosphofructokinase and acts as an allosteric inhibitor, this inhibition of phosphofructokinase results in slowing or stopping ATP production. There are also some enzymes that are allosterically inhibited in the citric acid cycle resulting in slowing down or stopping it, nadh and citrate also inhibit phosphofructokinase, in the other way around more ATP will be made if you don’t have enough. This is the alternate of alternate energy forms
Describe anaerobic respiration in prokaryotes (state other terminal electron acceptors besides O2)
Anaerobic respiration involves an electron transport chain that uses an inorganic substance other than oxygen as the terminal electron acceptor. Common inorganic substances that serve these purposes are sulfate SO4, nitrate NO3 and iron 3 ion Fe 3+, these organisms are rooted deep inside soil or marshes
Explain the processes of lactic acid fermentation and alcohol fermentation (also state which organisms undergo each process and what the products are used for by humans)
This process involves using an organic molecule as a final electron acceptor, it allows for cells to regenerate NAD+ and glycolysis to continue. Lactic acid fermentation occurs in animals, bacteria, and fungi. Pyruvate will accept electrons at the end becoming lactic acid. Its production oxidizes NADH to NAD+ so glycolysis occurs again. Basically glycolysis occurs forming glyceraldehyde 3 phosphate then it becomes pyruvate releasing NADH. Then the pyruvate takes the electrons from NADH and it gets converted to NAD+ which then restarts the cycle. The pyruvate gets turned into lactic acid. This process only releases 2 ATP. Lactic acid builds muscle and lowers pH, it also gets taken to the liver where it is converted back to pyruvate if oxygen is present. Alcohol fermentation occurs in yeart and some bacteria as well. Pyruvate is decarboxylated leaving acetaldehyde, then the acetaldehyde is reduced to ethanol and NADH is oxidized to NAD+. When pyruvate is decarboxylated Acetaldehyde is formed and that is what accepts the electrons from NADH oxidizing it. Some uses to alcahol fermentation is bread making, wine making, and vinegar production.
Describe the details on the Photo reactions (stage 1) of photosynthesis including starting and ending products, summary points, location and the process.
The photo reactions stage on or the light depended reactions take place in the thylakoid membrane. It starts in photosystem two when a photon of light 680nm strikes the complex. The energy is absorbed and transferred to the molecule P680 exciting one of its electrons and transferring it to the primary electron acceptor. This creates a positive P680 molecule and is extremely electronegative, its strong enough to remove an electron from water. This is done by water splitting enzyme. The water splitting enzyme also releases oxygen. The electron that is at the primary electron acceptor now gets picked up by plastoquinone and occurs twice. Plastoquinone transfers electrons to the next complex and releases the protons into the lumen increasing the proton gradient. There were also protons released from the water splitting enzyme which also increases the gradient. Then it keeps transferring electrons until it gets to photosystem 1. In photosystem 1 a 700nm light excites the electron and P700 is now positive charge. The P700 accepts electrons from plastocyanin and gets reduced. The electron in the primary electron acceptor gets picked up by ferredoxin and transferred to NADP+ reductase. In NADP+ reductase the electrons will get picked up by NADP+ and combine with H+ in the stroma to form NADPH. This NADPH will be used in the calvin cycle. As H+ gathers from the water splitting and plastoquinone the concentration of H+ increases in the thylakoid, the H+ concentration decreases on the stroma side as H+ is needed to make NADPH. The proton motive force created by ATP synthase then creates ATP. The starting producs are photons, H2O, NADP+ and ADP. The end products are O2, NADPH and ATP.
Alanine
Alanine – 3C remain = becomes pyruvate –
enters pyruvate oxidation
Glycine
Glycine - 2C remain = becomes acetyl -
enters Citric Acid Cycle
Proline
Proline – 5C remain = becomes α-
ketoglutarate – can be used in the Citric Acid
Cycle
Describe the details on the Synthesis reactions of photosynthesis including starting and ending products, summary points, location, and the process.
The synthesis stage or clavin cycle happens day and night and takes place in the stroma. Energy is needed from stage 1 (NADPH and ATP). CO2 is used to synthesise glucose.There are three parts, carbon fixation, reduction reactions and regeneration of RuBP. Rubisco is an enzyme that combines CO2 with RuBP. It works very slowly and only 3 molecules per second. Many copies are needed and half of the protein is In the leaf. In phase 1, 3 carbons combine with 3 RuBP using rubisco to form 3 6-phosphoglycerate, this molecule is very unstable and splits into two immediately resulting in 6 3-phosphoglycerate. Phase two is reduction reactions where 6 ATP is used, 6NADPH is used and the 6 pga is reduced to 6 glyceraldahyde-3-phosphate. 1 of the G3P molecules leaves the cycle to form ½ glucose. The other 5 G3P molecules go on to regenerate RuBP. Phase 3 is regeneration of RuBP. These are a series of enzyme catalyzed reactions. 5 G3P will be used to regenerate 3 RuBP for more carbon fixation. 3 ATP is used. Three turns of the Calvin cycle produces ½ glucose so 6 will be needed to produce a full glucose. The starting products are 3CO2, 9ATP, 6NADPH, 3RuPB. The end products are ½ glucose, 9 ADP + 9 Pi. 6 NADP+ and 3 RuBP (recycled).
Compare (state similarities and differences) the mitochondrion and chloroplast
The chloroplast encloses the stroma and the thylakoids, the mitochondria encloses the matrix and separates it from the intermembrane space. Both contain DNA. The location of the H+ in chloroplast in the thylakoid lumen and the mitochondria it’s the intermembrane space. The chloroplast is also more complex than the mitochondria.
Compare cellular respiration and photosynthesis
In cellular respiration and photosynthesis there are different reactants and products. The source of energy in photosynthesis is photon and in cellular respiration its glucose. The electron carriers are also different in photosynthesis its NADPH and in cellular respiration its oxygen. The source of electrons in photosynthesis water and in cellular respiration its glucose. The products in cellular respiration is H2O but in photosynthesis its NADPH.
Compare anaerobic and aerobic cellular respiration
In anaerobic cellular respiration there can be fermentation or an inorganic molecule that accepts electrons at the end of the ETC. In aerobic respiration oxygen is needed and cellular respiration takes place. Oxygen is the final electron acceptor in the ETC.