Ch. 8&9- All the ones breaking bigger molecules to make smaller are catabolic (cellularrespiration). Building small molecules to make a big is anabolic (photosynthesis).- Metabolic reactions are a chain of reactions. - Biochemical pathway/ metabolic pathway: AB (B becomes a reactant for the next reaction) C (and so on)- Things we can do efficiently are due to the help from these metabolic reactions. They’re constantly transferring matter and energy from on form into another. - Potential energy (chemical, atomic): all the bonds between chemicals, water behind the dam, roller coaster on a top point. - Kinetic energy (heat, sound, light): moving- Electromagnetic spectrum has different potential energies that appear in form of waves. - High frequency waves (faster, more wavelengths. Short wavelengths. Gamma rays, x-rays). - Energy is measured in small c. what we eat and burn is kCal. - 1000 calories = 1 kCal (big C)- Thermodynamics: 1st law is conservation of energy. All that we eat is in the form of potential energy but we use in in the form of kinetic energy. 2nd law: every time you transform energy from one form to another, there is some waste known as heat. The heat is unusable and is dispersed in the environment. Increases entropy (increase in disorderliness. **More order, less stable. Less order, more stable**).- Spontaneous: a lot of reactions in the cell happen randomly. Every time this happens, it increases the disorderliness (or atrophy). Also, it happens without any kind of energy requirement. - You may be brining order in a little system, but still the universe has its disorderliness. It takes a lot of energy to maintain that order. - Gibbs’ Free energy: how much of it is available to do some work/ break or make a bond? We assume the temperature and pressure is constant when this energy is available. Gibbs came up with this concept. When we talk aboutliving cells…what is the energy available to make bonds/break bonds?- Which reactions are spontaneous and non-spontaneous? Which would require energy and which wouldn’t? We can use Gibbs formula for it. - Enthalpy: total energy available in the system (H) Entropy: disorderliness (S) Gibbs energy (G) temperature (T in Calvin units).- UNDERSTAND THIS EQUATION (in ppt.)- If H, T and S increase, G would decrease. - -G = Spontaneous +G = Non-spontaneous- If temperature is constant and when something is produced from a reaction, some kind of energy, for example, heat is reduced in to the environment. And H would decrease along with S and whenever you have a high S, the G is low. - Purine: nitrogenous base, phosphate group.- Once the hydrolysis of ATP occurs, the phosphate group that’s being released is displaced. This is called de-phosphorylation. - Endogenic reaction: + (activation energy is high) Endogenic reaction: -- Most spontaneous reactions will eventually occur. Most enzymes are protein catalysts. - Activation energy/initial energy required for the reactants to reach a transition stage. No matter what kind of reaction it is, it still requires some energy. Enzymes decrease the initial energy required to reach the transition stage. The total energy released by the reaction (G) doesn’t get affected by theenzyme. - The shape of products will be different from what enzyme should fit in there. - Most living cells have enzymes that are active at 37° C- Coenzymes: they’re organic, participate in reactions but are usually unchanged- Cofactor: non-protein molecule, tend to be inorganic mostly but can be organic. - There are several molecules that mimic the substrates that bind to the enzyme. They are inhibitors and inhibit the reaction from occurring. Most of the times, you can get rid of competitive inhibition by increasing the substrate concentration. - Enzyme regulation depends on the turning on/off of genes.- Examples of activator: ADP and can act as an enzyme activator. When it binds to the enzyme its in active form.- Feedback inhibition mostly is allosteric regulation. - Cellular respiration: Where all the biomolecules can be broken down and produce byproducts. - Oxidize: (oxygen is electronegative atom so it pulls electrons towards itself soits being reduced because its gaining electrons). - When we have a reaction in an uncontrolled situation, when it reacts with oxygen, you have an explosion of heat. If this happened in cell, most wouldn’t be used for cellular respiration since its lost most of its heat. - Know the cellular respiration formula. - Know what dehydrogenase does. - More electronegative atoms will keep gaining electrons (oxygen) and reduce itself in charges- Glucose becomes oxidized in cellular respiration. - Making of ATP is called chemiosmosis and electron transport chain together is called oxidative phosphorylation. - Glycolysis is one step that always occurs and they’re pretty much the same in all organisms. The ATP it makes is little and goes through 2 phases: energyinvestment phase and energy payoff phase. Here we’re talking about 1 glucose molecule, you use 2 ATP and make 4 ATP so you have a profit gain of 2 ATP.- 1 phase: when you see Kinase, you are transferring phosphate group. - Most important step in glycolysis: enzymes are regulated. Fructose 6 phosphate, add an ATPA making it Fructose 1,6 bi-phosphate so it becomes very unstable molecule with 2 phosphate group, an important enzyme (phosphofructokinase) because it is allosteric inhibited. - Dehydrogenase: removes a hydrogen (triose phosphate dehydrogenase removes it from glyceraldehyde 3-phophate and adding it to NAD+)- Substrate level phosphorylation: know what it is!!- Glucose then produces 2 pyruvates and 2 NADH which is reduced form because it has picked up 2 electrons and 1 proton, the other proton goes into the solution, cytosol. Know what goes in and what comes out. - In glycolysis NO C02 came out. - If oxygen is present it will enter cellular respiration. - Now the pyruvate is a 3-carbon molecule. This will enter mitochondrial matrix. The transport protein transfers it there. The first reaction that occurs is the oxidation of this pyruvate molecule and loses some electrons and gives it to NAD+ and produces NADH and first C02 molecule is released in this reaction. You still have 2 CO2 molecules left that attach to the coenzyme A (organic molecule).- Cancer cells tend to favor glycolysis pathways. - KNOW PYRUVATE OXIDATION. After this the end product: C02, NADH, acetyl-CoA- The products go to the next cycle:
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