Presentation on theme: "What happens to chemical bonds during chemical reactions"— Presentation transcript:
1 What happens to chemical bonds during chemical reactions How do energy changes affect whether a chemical reaction will occurWhat role do enzymes play in living things and what affects their functions
2 2.4 Chemical Reactions and Enzymes Ch 2 Chemistry of Life2.4 Chemical Reactions and Enzymes
3 Everything that happens in an organism—its growth, its interaction with the environment, its reproduction, and even its movement—is based on chemical reactions.
4 Chemical ReactionProcess that changes, or transforms, one set of chemicals into another by changing the chemical bondsMass and energy are conservedReactantsElements or compounds that enter into a chemical reactionProductsElements or compounds produced by a chemical reaction.
5 Chemical Reaction Example Carbon dioxide (CO2) in the blood reacts with water to produce carbonic acid (H2CO3)Reaction is reversed in the lungs and produces carbon dioxide gas, which you exhale.
6 Energy ChangesEnergy is released or absorbed whenever chemical bonds are formed or brokenChemical reactions that release energy often occur on their ownChemical reactions that absorb energy will not occur without adding energy.
7 Energy Changes Example Energy is released in the form of heat, and sometimes—when hydrogen gas explodes—light and sound2 H2 + O2 → 2 H2OTo reverse the reaction is to pass an electrical current through water to decompose water into hydrogen gas and oxygen gas2 H2O + energy → 2 H2 + O2.
8 Energy SourcesPlants get their energy by trapping and storing the energy from sunlight in energy-rich compoundsAnimals get their energy when they consume plants or other animals.
9 Activation EnergyEnergy that is needed to get a reaction started.
10 Enzyme Large protein Type of Catalyst Substance that speeds up the rate of a chemical reactionPromote chemical reaction by lowering activation energyReusable.
11 EnzymeSpeed up chemical reactions that take place in cells.
12 The Enzyme-Substrate Complex Active siteWhere action occursSubstrateWhat you are putting together or taking apartNeeds to fit exactly in the active siteEnzyme Substrate complexWhen substrate is in active siteProductEnd product of reaction.
13 EnzymeVery specific, generally catalyzing only one compound.
14 How Enzymes WorkSubstrate shape is particular to fit in active site of enzymeEnzyme will apply pressure on the bond by bending it making that bond easier to breakOREnzyme holds the substrates in correct position/alignment so a bond can form.