Term
| What is cellular metabolism? |
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Definition
| All the chemical reactions occuring in a cell |
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Term
| Cellular metabolism deals mostly with what? |
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Definition
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Term
| What goes in and what comes out during chemical reactions? |
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Definition
| Reactants go in, products come out |
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Term
| When is equilibrium reached? |
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Definition
| When there is no net change in reactants and products |
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Term
| Why is it that in most chemical reactions 100% of reactants don't turn into products? |
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Definition
| Because chemicals are constantly in motion, so products are being turned back into reactants... so it will never reach 100% |
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Term
| What are the two main categories of chemical reactions? |
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Definition
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Term
| How do Endergonic reactions work? |
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Definition
| Endergonic (requiring energy input), usually occurs to build larger chemicals, which store the energy as potential energy. |
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Term
| How do exergonic reactions work? |
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Definition
| Energy "exits" when large chemicals, like glucose, are broken down to release energy. |
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Term
| What kind of chemical reactions causes energy to be released? |
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Definition
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Term
| What kind of chemical reaction requires energy inuput? |
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Definition
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Term
| What is the most important chemical in your cells regarding energy? |
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Definition
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Term
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Definition
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Term
| Is ATP immediately accessable, or is it a long term storage chemical? |
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Definition
| ATP is for immediate energy use, and cells cannot survive for more than 2-3 minutes without it. |
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Term
| How much work within a cell is ATP responsible for? |
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Definition
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Term
| What is responsible for chemical reactions coupling? |
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Definition
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Term
| Why is there so much energy in ATP? |
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Definition
| It has phosphate bonds, which have a lot of energy. When broken, it releases this energy very quickly. |
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Term
| Why do phosphate bonds have so much energy? |
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Definition
| Because each phosphates has a negative charge, so they are repelling each other. Hodling them close together takes a lot of energy. When that bond is broken it releases that energy. |
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Term
| What functions in a cell does ATP power? |
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Definition
| Endergonic reactions, muscle contractions, and active transport, all rely on energy from ATP |
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Term
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Definition
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Term
| What happens when you use ATP energy? |
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Definition
| You then have a lot of ADP and phosphates floating around, which are then recycled back into ATP |
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Term
| "Products of one reaction are reactants for the next reaction" is describing what process? |
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Definition
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Term
| energy released from exergonic reactions is used for energonic reactions is an example of what? |
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Definition
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Term
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Definition
| Proteins that will speed up chemical reactions |
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Term
| All chemical reactions in living organisms require what? |
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Definition
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Term
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Definition
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Term
| Enzymes often have what suffix? |
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Definition
| "-ase" Lactase, sucrase, etc |
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Term
| How do enzymes speed up chemical reactions? |
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Definition
| By lowering the activation energy |
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Term
| What is activiation energy? |
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Definition
| The amount of chemical reactions that the reactants have to absorb to get started. |
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Term
| What kind of reactions require activation energy? |
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Definition
| Both endergonic and exergonic reactions require activation energy. |
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Term
| Why doesn't the glucose in your body randomly break down? |
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Definition
| The activation energy - for those glucoses to start breaking down, they would have to absorb some energy. |
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Term
| How do enzymes lower activation energy? |
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Definition
| They can bind the two reactants and hold them close together, or put them in the right orientation (place). The proteins in the enzymes can also create micro-environments (acidic, hydrophilic, etc) that can foster reactions. |
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Term
| What is the "lock and key" model? |
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Definition
| The idea that enzymes (like all proteins) have a specific shape, and the most important part of the enzyme is called the "active site" or "lock". That's where the reactant (or "key")binds. |
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Term
| What directly determines the shape of an enzyme? |
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Definition
| The order of amino acids which compose it |
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Term
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Definition
| The part of the enzyme that binds to the reactant |
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Term
| What do you call a reactant when an enzyme is present to help it along? |
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Definition
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Term
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Definition
| The name of the reactant when an enzyme is present |
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Term
| In what ways are enzymes selective? |
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Definition
| Both the shape and the chemistry must mesh with the chemicals' or it won't affect reactions |
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Term
| Are enzymes reactants or products? |
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Definition
| Neither; they're bystanders and can be used repeatedly. |
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Term
| Do enzymes effect the equilibrium point? |
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Definition
| No, they just help the chemicals get there faster |
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Term
| If two chemicals normally don't bind together, what will happen if we add enzymes? |
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Definition
| Nothing; we can't magically make chemicals react. enzymes only speed the natural procss up |
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Term
| How much do enzymes speed up chemical reactions? |
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Definition
| Anywhere from 1,000x to 1,000,000x faster (one thousand to one million) |
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Term
| How many reactions can a single type of enzyme speed up? |
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Definition
| Just one, enzymes are selective |
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Term
| Could missing only one enzyme pose health problems? |
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Definition
| Yes. One example is ADA, which results in your immune system breaking down because you can't break down the proteins like normal. |
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Term
| What happens when a cell doesn't need the reaction that the enzyme speeds up to occur at all? |
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Definition
| The cells don't break down the enzyme; instead they use chemical inhibitors. |
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Term
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Definition
| Any chemical that interfere's with an enzyme's activity. |
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Term
| How does an inhibitor work? |
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Definition
| It binds to an enzyme, which temporarily prevents it from reacting. |
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Term
| Is an inhibitor permanent? |
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Definition
| No. Chemicals are always in motion, so eventually while bouncing around they will break apart. |
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Term
| How does a cell keep an enzyme inhibited if the inhibitor is temporary? |
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Definition
| The cell must continually create inhibitors to bind to the enzyme |
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Term
| How does a competitive inhibitor work? |
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Definition
| It physically binds onto the active site of the enzyme, which blocks the substrate from getting to the enzyme |
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Term
| Can a competitive inhibitor be vastly different than the substrate it is blocking? |
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Definition
| No; if the competitive inhibitor is physically binding to the enzyme, which has a very specific 3 dimensional active site (or "lock") it must be at least moderately chemically similar. |
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Term
| How do non-competitive inhibitors work? |
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Definition
| They bind anywhere else on the enzyme (other than the active site) which changes the shape, so the active site is still there but no longer the same shape. |
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Term
| Can non-competitive inhibitors be vastly different than the substrate it is blocking? |
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Definition
| Yes; the non competitive inhibitor attaches somewhere else other than the active site, so it doesn't necessarily have to be a similar shape. |
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Term
| Do chemical reactions occur in isolated incidents? |
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Definition
| No, most chemical reactions occur in chains |
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Term
| Are most cellular products quickly produced? |
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Definition
| No, often times it takes many small steps to get a needed product |
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Term
| If we have chain A>B>C>D>E>F>G and now have enough G, how do cells often times inhibit the enzymes? |
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Definition
| Instead of inhibiting the 6 > (which would all be different enzymes) G (or other product near end of chain) would act as a non-competitive inhibitor for the enzyme between A and B, effectively shutting down the other processes as well. |
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Term
| What is feedback inhibition? How does it work? |
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Definition
| Feedback inhibition is when a product down the chain acts as an inhibitor for an early enzyme. If there is too much of the end products, it starts to inhibit the process and it stops getting produced. If there is not enough of the end product, it no longer has excess to act as an inhibitor and the pathway opens up again. |
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Term
| How do poisons relate to inhibitors? |
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Definition
| Many poisons are enzyme inhibitors. For example, Penicilin inhibits bacteria's ability to make cell walls. Certain pesticides inhibit enzymes in the nervous system and paralyze and kill insects |
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Term
| What are some factors that influence an enzyme's efficency? |
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Definition
| The enzyme concentration, the substrate concentration, temperature, or pH. |
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Term
| What happens when you denature an enzyme? |
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Definition
| the enzyme's 3-d shape is broken down |
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Term
| What effect does temperature have on enzyme reaction rates? |
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Definition
| Increase in temperature leads to increase in reaction rate, until optimum temperature is reached. After that if you continue to raise the temperature the rate declines almost to 0 immediately. |
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Term
| What is optimum temperature? |
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Definition
| The temperature where the reaction is occuring as fast as it possibly can |
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Term
| What can cause denaturing in an enzyme? |
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Definition
| Temperature too high, or chemicals such as pH. |
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