Interim Slides Part 4

8/14/2019 Interim Slides Part 4

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Part 4

Biochemistry


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What Happens in a ChemicalReaction?

Chemical reactions occur when atoms rearrange.

(Methane CH4) (and oxygen O2) (reactants) react to form(carbon dioxide CO2) (and water H2 ) (O products)

.Notice how atoms have switched partners or rearranged


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What is Storing MoreEnergy?

If energy was released, it means that theproducts store less energy than thereactants. This is an exothermic reaction.

E

N

E

RG

Y

Reactants

ProductsEnergy is

released


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What is Storing MoreEnergy?

If energy is absorbed, it means that theproducts store more energy than thereactants. This is an endothermicreaction.

E

N

E

RG

Y Reactants

Products Energy isabsorbed


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Some Chemical Reactions are VERYFAST

NaClClNa 222+

,Reaction between chlorine Cl 2( ) , ,green gas and sodium metal produces NaCl salt

Click on the Hyperlink below to view the full video withaudio of this very fast exothermic reaction.
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.htmlhttp://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.html


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Lets Go Back to the ReactionBetween Methane and Oxygen

When the oxygen and methane molecules ,collide thecollisionhas to be STRONG enough to break the bonds

.that already exist If the collisiondoes not have, .enough energy the reaction does not happen At roomtemperaturemoleculesof methane gas and oxygen collide

but not STRONGLY enough for the reaction .to happen


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Activation Energy

The minimum amount of energy necessaryto get a reaction going is called theactivation energy, EA.

All reactions have a certain amount ofactivation energy that must beovercome for the reaction to occur

( =and or EA) and orientation.
http://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asphttp://chem.salve.edu/chemistry/temp2a.asp


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Exothermic Reactionand EA

Before the reaction gets to the lower level of theproducts, it must get over the hump of theactivation

.energy


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Endothermic Reactionand EA

For the reactionto get to the higher energy levelof the products, the activation energymust be

supplied and stored in the bonds of the products.


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Activation Energy Affects theRate of a Reaction

The greater the required activation energy of areaction, the slower the reaction will proceed.

If the required activation energy is lowered, areaction will proceed faster.


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Catalysts

A catalystis a substance that makes areaction go faster by lowering therequired activation energy.

AcatalystIS NOT changed or used up in areaction.


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The blue line represents areaction without a

catalyst.

The red line representsa reaction where a

catalyst .was added

The activationenergyislower so the reaction

.will go faster

Effect of a Catalyst


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Decomposition of HydrogenPeroxide

2222 22 OOHOH +

Hydrogen peroxide H2O2decomposes by itself.into hydrogen gas and water

.This reaction normally happens VERY SLOWLY Ifa catalyst ( )such as potassium iodide KI is

, .added the reaction occurs much faster

Click Here for Reaction Video
http://www.planet-scicast.com/view_clip.cfm?cit_id=2585http://www.planet-scicast.com/view_clip.cfm?cit_id=2585http://www.planet-scicast.com/view_clip.cfm?cit_id=2585


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Biological Catalysts -Enzymes

Living organisms also have catalysts that speedup reactions.

These catalysts are called enzymes.

Enzymes in the blood catalyze the decompositionof hydrogen peroxide. That is why applying

hydrogen peroxide on a wound makes it foamy.

REVIEW


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REVIEWFactors That Affect

Reaction Rate Temperature: more collisions means faster reaction rate

Concentration: more reactants means faster reaction rate

Pressure: more collisions means faster reaction rate

Catalyst: loweractivation energy means faster reaction rate

Surface Area Greater surface area means more collisions for afaster reaction rate

pH Optimal pH means faster rate of reaction


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( )Multiple Choice MC FCAT Question

Catalysts may reduce the amount of activation energy required for a chemical. ( )reaction to occur Platinum Pt is a catalyst that is used in the catalytic

. ,converters in automobiles In the graphs below pathway x is a solid line

.representing the uncatalyzed reaction The dotted line shows the catalyzed.reaction Which graph bestillustrates the changes in a reaction when the catalystreduces the amount of energy required?


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- ( )Short Response SR FCAT Released Question

REPORT ON THE 2006 FCAT SCIENCE RELEASED ITEMS
http://smb//tmp/sv134.tmp/FL06_Inquires_final_tagged.pdfhttp://smb//tmp/sv134.tmp/FL06_Inquires_final_tagged.pdfhttp://smb//tmp/sv134.tmp/FL06_Inquires_final_tagged.pdf


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StudentResponses :SCORE 1

Catalysts are not used up in areaction


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Key Concept:What Kinds of Biochemical Reactions Occur in

Cells?

What is photosynthesis? How does photosynthesis occur? What is glucose? What is cellular respiration?

Why do organisms need to perform respiration?

Click here to view animations about the relationship between

photosynthesis and cellular respiration:1. http://glencoe.mcgraw-hill.com/sites/0078695104/student_view0/brain_

Technology LAB:GIZMOS- www.explorelearning.com1. Cell Energy Cycle (Photosynthesis/Cell Respiration)2. Interdependence of Plants and Animals
http://smb//tmp/sv134.tmp/Brain%20Pop%20Movies.htmhttp://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=455http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=466http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=466http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=455http://smb//tmp/sv134.tmp/Brain%20Pop%20Movies.htm


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Sample FCAT Questions

Energy from food is made available to cells by the process ofcellular respiration. In this biochemical reaction, water and carbondioxide are produced from the breakdown of:

A. minerals B. glucose C. ATP D. vitamins

What do you need to know in order to answer thisquestion?


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Sample FCAT Questions

Energy from food is made available to cells by the process ofcellular respiration. In this biochemical reaction, water andcarbon dioxide are produced from the breakdown of

A. minerals B. glucose C. ATP D. vitamins

Correct answer: B


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Key Concept: What is the Role of Glucose?

It is found in plant andanimal material that isused for food.

Glucose molecules arebroken down through aseries ofchemicalreactions known ascellular respiration sothat energy can bereleased and used bythe cells.

Click forGlucose SongKaraoke


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Key Concept:What is the Role of Proteins in Cells?

The structure of a protein determines its function in acell.

Proteins:

Act as transporters

Can form enzymes

Control chemical reactions in cells

Technology Lab:GIZMOS- www.explorelearning.com Dehydration Synthesis (Proteins)
http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=464http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=464


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Sample FCAT Question

One function of cell membrane proteins is the active transport ofmaterial across the membrane. What does this do for the cell?

A. The transport proteins only allow dissolved salts into thecell.

B.The transport proteins only allow complex external proteinsinto the cell.

C. The transport proteins regulate quantities of internalchemicals.

D. The transport proteins allow water to flow in and out of thecell easily.

What do you need to know in order to answer thisquestion?


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Sample FCAT Question

One function of cell membraneproteinsis the active transportof

material across the membrane. What does this do for the cell?

A. The transport proteins only allow dissolved salts into thecell.

B. The transport proteins only allow complex external proteinsinto the cell.

C. The transportproteins regulate quantities of internalchemicals.

D. The transport proteins allow water to flow in and out of thecell easily.

Correct Answer: C


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Group Discussion Questionfor Key Concept #1

What kinds ofbiochemical reactions occur in cells?

Click for Answer:

Many biochemical reactionsoccur in cells. Onefamiliar biochemical reaction is photosynthesis, in whichplant cells create the sugar glucose (the major source ofenergy for living things) from the energy of the sun. As aresult ofphotosynthesis, plant and animal cells use glucosemolecules in the biochemical process ofcellular respiration

in order to obtain useful energy for cells.


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What is the role ofglucose in cells? Click for Answer:

Glucose is a simple sugar produced byphotosynthesis, and is found in plant andanimal material that is used for food.

Glucose is the molecule that is broken apart

during cellular respiration so that energyfrom this molecule can be released and used bycells.


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What is the role ofproteinsin cells?

Click for Answer:

Proteinsare important to cells for several reasons.First of all, the shape and structure of aproteinsdetermines its function in a cell. Mostenzymes are proteins. In addition, proteins act astransporters, helping cells pump in certain neededmaterials such as specific hormones, potassium, salts,

etc. Through activetransport. In other words,proteins control chemical reactionswithin cells. Inaddition, proteins form structures for long-termnutrient storage.


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How does DNA tell a cell what to do?

Click for Answer: DNA is the genetic code found in the

nucleus of the cell and makes specialproteinsfor the cell to use. Allbiochemical reactions are based onthe coded information on molecules ofDNA. DNA is literally the set of directionby which cells functions.


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Short Response SC.A.1.4.4

To produce sulfuric acid (H2SO4), one industrial plant uses the

contact process, which consists of several reactions. The initialreaction in this process uses sulfur dioxide (SO2 ) and oxygen (O2 )in the presence of vanadium oxide (V2 O5) pellets to produce sulfurtrioxide (SO3) as shown below. V2O5 Pellets 2S02 (g) + O2 (g) ---------------- 2SO 3 (g) Sulfur Oxygen Sulfur Dioxide trioxidea r t A In the reaction between SO2and O ,2 what is the role of the V2O 5

pellets?

art B Explain what the industrial chemist could do to increase the.efficiency of the reaction

he vanadium oxide pellets serve as a catalyst in the reactionetween SO nd O2.

,o increase the reaction s efficiency the chemists could increase.he temperature at which the reaction occurs


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Short Response SC.A.1.4.4

Magnesium (Mg) in solid form can chemically react with chlorine(Cl2)gas to form magnesium chloride (MgCl2). This reaction isexothermic.

Mg + Cl2 ------------- MgCl2 + Heat

In the reaction between Mg and Cl2 , what determines howquickly the reaction will occur? Explain your answer.

The rate of a reaction depends on the urfacerea of the Mg and the concentration .of the Cl2,Also the pressure and temperature of the

reactants will have an effect on the rate of.reaction The number of molecules interacting and

the energy in those molecules will determine the.rate of reaction


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Short Response SC.D.1.4.2

:a rt A h e o ce a n ic p la te s a re m o vin g a w ay fro m.a ch o th e r

T h e -id A tla n tic R id g e in th e A tla n tic O ce a n h a s b e e n stu d ie d.b y scie n tists fo r m a n y ye a rs T h e fo rm a tio n s p ro d u ce d b y th e-id A tla n tic R id g e y ie ld s clu e s to th e co m p o sitio n o f E a rth s

.crust

a rt A n w h a t d ire ctio n a re th e tw o o ce a n ic p la te s a t-he Mid Atlantic Ridge moving in relation to each other?a r t B xplain how a volcano can be produced by.he movement of these plates

:art B hen only a thin layer of crust is present,etween these spreading plates magma may.e released The larva may then rise and,pread upward and outward forming a.olcano

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Interim Slides Part 4