Student Exploration: Cell Energy Cycle

Transcription

1 Name: Date: Student Explratin: Cell Energy Cycle Vcabulary: aerbic respiratin, anaerbic respiratin, ATP, cellular respiratin, chemical energy, chlrphyll, chlrplast, cytplasm, glucse, glyclysis, mitchndria, phtsynthesis, radiant energy Prir Knwledge Questins (D these BEFORE using the Gizm.) 1. What des a plant need t survive and grw? 2. What des an animal need t survive and grw? 3. Hw d animals and plants depend n each ther? Gizm Warm-up The Cell Energy Cycle Gizm illustrates tw prcesses that are essential t life: phtsynthesis and cellular respiratin. Althugh bth f these reactins invlve a series f cmplex steps, the basic reactants and prducts in each prcess are fur relatively simple mlecules. 1. What is the chemical frmula f xygen? 2. Glucse is a simple sugar. What is the chemical frmula f glucse? 3. What is the chemical frmula f carbn dixide? 4. What is the chemical frmula f water?

2 Activity A: Phtsynthesis Get the Gizm ready: If necessary, click Reset. Check that the PHOTOSYNTHESIS tab is selected. Check that Descriptin is turned n. Intrductin: Phtsynthesis ccurs in the chlrplast, an rganelle fund in plant and algae cells. Within the chlrplast, a green pigment called chlrphyll cnverts the radiant energy f sunlight int chemical energy that the plant can use. Questin: What are the reactants and prducts f phtsynthesis? 1. Predict: Of the mlecules shwn n the CHEMICALS pane, which d yu think are reactants (ingredients) in phtsynthesis? Which d yu think are prducts? Reactants: Prducts: 2. Explre: Drag each mlecule frm the CHEMICALS pane t the chlrplast n the PHOTOSYNTHESIS pane. If a mlecule is a reactant, it will stay in the chlrplast. Which mlecules are reactants in phtsynthesis? 3. Observe: Click Add light and lk at the Output. What are the prducts f phtsynthesis? 4. Summarize: A chemical equatin shws reactants n the left side f an arrw, and prducts n the right, like this: reactant + reactant prduct + prduct. Based n yur bservatins, what is the chemical equatin fr phtsynthesis? Turn n Shw chemical equatin t check. Were yu crrect? 5. Challenge: A chemical equatin is balanced when each side f the equatin includes the same number f each type f atm. A. Is the equatin balanced as written? Why r why nt? B. If yu are familiar with balancing equatins, balance the phtsynthesis equatin. Write the balanced equatin belw, and then check yur wrk by clicking Balance.

3 Activity B: Cellular respiratin Get the Gizm ready: Click Reset. Select the RESPIRATION tab. Intrductin: Cellular respiratin ccurs in the cytplasm f the cell and in mitchndria, rganelles fund in all cmplex cells. (Bacteria and ther simple rganisms d nt cntain mitchndria.) The Gizm shws a green mitchndrin surrunded by blue cytplasm. Questin: What are the reactants and prducts f cellular respiratin? 1. Predict: Of the mlecules shwn n the CHEMICALS pane, which d yu think are reactants (ingredients) in cellular respiratin? Which d yu think are prducts? Reactants: Prducts: 2. Explre: Drag each mlecule frm the CHEMICALS pane t the RESPIRATION pane. Which mlecules are reactants in cellular respiratin? 3. Observe: Click Next. What happens in the cytplasm? This prcess is called glyclysis. The wrd Pyruvic is shrt fr pyruvic acid, a prduct f glyclysis. Glyclysis prduces energy, which is stred in the frm f ATP (adensine triphsphate) mlecules. Glyclysis results in a net prductin f tw ATP mlecules. 4. Observe: Click Next. What happens nw? 5. Observe: Click Next. What happens in the mitchndrin? Energy frm the mitchndrin is als stred in the frm f ATP. Thirty ATP mlecules are prduced fr every tw mlecules f pyruvic acid. 6. Analyze: Cellular respiratin invlves tw phases. Anaerbic respiratin des nt invlve xygen, while aerbic respiratin des. Where des each phase take place? Anaerbic respiratin: Aerbic respiratin: (Activity B cntinued n next page)

4 Activity B (cntinued frm previus page) 7. Summarize: Based n what yu have seen, what is the verall chemical equatin fr cellular respiratin? Turn n Shw frmula f chemical equatin t check. Were yu crrect? 8. Challenge: A chemical equatin is balanced when each side f the equatin includes the same number f each type f atm. A. Is the equatin balanced as written? Why r why nt? B. If yu are familiar with balancing equatins, balance the cellular respiratin equatin. Write the balanced equatin belw, and then check yur wrk by clicking Balance. 9. Extend yur thinking: When yu think f the wrd respiratin, yu might think abut the prcess f breathing, which is actually called ventilatin. (The respiratry system cnsists f the windpipe, lungs, etc.) Hw is breathing related t cellular respiratin? (Hint: Think abut bth the reactants and the prducts f cellular respiratin.) 10. On yur wn: If n xygen is present, pyruvic acid breaks dwn t frm lactic acid. Yu can feel the effects f lactic acid if yu exercise very hard. One way t prduce lactic acid is t d a wall sit, supprting yurself against a wall in a sitting psitin. Try ding this fr a few minutes. What d yu feel in yur thigh muscles?

5 Activity C: The carbnxygen cycle Get the Gizm ready: Click Reset. Select the CYCLE tab. Questin: Hw is phtsynthesis related t cellular respiratin? 1. Frm a hypthesis: Hw d yu think phtsynthesis is related t cellular respiratin? 2. Predict: Lk at the red arrws, and think abut the phtsynthesis and respiratin reactins. Each red arrw cnnects a set f reactants t the prducts f the reactin. A. Which chemicals wuld yu expect t find at the tp f the diagram? Explain. B. Which chemicals wuld yu expect t find at the bttm f the diagram? Explain. 3. Observe: Drag the Oxygen, Glucse, Carbn dixide, and Water int the CYCLE pane. A. Which substances are reactants in phtsynthesis? B. Which substances are prducts f phtsynthesis? C. Which substances are reactants in respiratin? D. Which substances are prducts f respiratin? 4. Cmpare: Hw are the reactants and prducts f phtsynthesis and respiratin related t ne anther? (Activity C cntinued n next page)

6 Activity C (cntinued frm previus page) 5. Review: In phtsynthesis and respiratin, energy is cnverted frm ne frm t anther. Light is a frm f radiant energy. Glucse and ATP mlecules stre chemical energy. A. In the phtsynthesis chemical equatin, des the radiant energy f the Sun act as a reactant r a prduct? Explain yur answer. B. In phtsynthesis, what frm f energy is sunlight cnverted t, and hw is this energy stred? C. In the respiratin equatin, des energy act as a reactant r a prduct? Explain. D. Hw is the energy prduced by respiratin stred? 6. Summarize: Hw are respiratin and phtsynthesis related t each ther? 7. Think and discuss: In what ways are plants and animals dependent n each ther?

7 Vcabulary: Cell Energy Cycle Vcabulary Aerbic respiratin a chemical prcess in which xygen is used t prduce energy frm carbhydrates. Aerbic respiratin prduces much mre energy than anaerbic respiratin. Aerbic respiratin results in the frmatin f 30 t 38 ATP mlecules per mlecule f glucse. Anaerbic respiratin a chemical prcess in which carbhydrates are partially brken dwn withut using xygen. A small amunt f energy is prduced in this manner. Anaerbic respiratin prduces much less energy than aerbic respiratin, resulting in the frmatin f 2 ATP mlecules per mlecule f glucse. ATP adensine triphsphate, a mlecule that prvides energy fr cellular prcesses. Energy is released when an ATP mlecule is cnverted t an ADP (adensine diphsphate) mlecule. Cellular respiratin a prcess by which energy is released frm fd. When xygen is present, xygen and glucse cmbine t prduce energy in the frm f ATP mlecules. The by-prducts f cellular respiratin in the presence f xygen are carbn dixide and water. When xygen is nt present, a smaller amunt f energy is prduced frm the breakdwn f glucse. Pssible by-prducts include lactic acid and alchl. Chemical energy energy that is released r absrbed in chemical reactins. In the cell, chemical energy is stred in glucse mlecules and ATP mlecules. Chemical energy is released when glucse mlecules are brken dwn and when ATP mlecules are cnverted t ADP. Chlrphyll a green pigment inside chlrplasts that cnverts light energy int a chemical frm the plant can use. Chlrplast an rganelle fund in the cells f plants and algae that cntains chlrphyll and is the site f phtsynthesis. Cytplasm a jelly-like substance cmpsed mainly f water and fund between the cell membrane and the nucleus. Glucse a simple sugar that serves as the majr energy surce fr all cellular prcesses. The chemical frmula f glucse is C 6H 12O 6.

8 Glyclysis a prcess by which glucse is partially brken dwn int pyruvic acid withut the use f xygen. Glyclysis ccurs in the cytplasm f the cell. Mitchndria rganelles fund in eukarytic cells that are the site f aerbic respiratin. Phtsynthesis the prcess by which light energy is used t cmbine water and carbn dixide int glucse and xygen. Radiant energy energy in the frm f electrmagnetic radiatin. Light and heat are examples f radiant energy.