Unit 5 Cellular Energy

I. Enzymes (159) There are countless numbers of chemical reactions occurring in every cell all the time. Virtually all of these reactions require the action of _______, catalytic __________. A catalyst _________a chemical reaction without being _______________________. An enzyme works by lowering the activation energy, that is the energy required to __________________. enzymes proteins Speeds up Used up in the reaction Get the reaction going

Enzymes share four common features: A. Enzymes work best within a narrow _____ and _____________ range. This is because of the importance of the ______ or ____________ of the enzyme. When the pH or temperature is altered, the _____________ and interactions are also changed, changing the shape of the enzyme. pH temperature shape conformation Chemical bonds

B. Enzymes do not make a reaction happen that couldn’t happen on its own; they simply make the reaction occur much _________. C. Enzymes are not ________________. The same enzyme may be used over and over again. faster Used up in the reaction

D. Enzymes are __________________. The substrate is the___________ D. Enzymes are __________________. The substrate is the___________. The substrate fits into a portion of the enzyme called the ____________. As the substrate fills the active site, this leads to a phenomenon known as __________, almost like a _________. It is this induced fit that is responsible for lowering the ________________of the reaction. Substrate-specific reactant Active site Induced fit squeeze Activation energy

Metabolism (218-221) All chemical reactions in a cell are referred to as cell ______________ Metabolic pathways- series of chemical reactions in which the __________of one reaction is the ___________for the next reactions. metabolism product reactant

2 Types: Release energy A. Catabolic pathways- _____________by breaking down larger molecules into smaller molecules EX. Cellular Respiration- ______ molecules broken down to release _______ for cell to use. B. Anabolic pathways- use the energy released by catabolic pathways ______________molecules from ______________ molecules. EX. Photosynthesis- ______________from Sun is ______________ to ______________in form of glucose. The relationship of anabolic & catabolic pathways results in the ________________________within an organism as well as within an ecosystem. organic energy To build larger smaller Light energy converted Chemical energy Continual flow of energy

III. CHEMICAL ENERGY AND LIFE (pp. 218-221) A. Energy and Life Energy is the ___________________. Cells require energy for ________ reactions, _____ transport,________, and maintaining ___________. We obtain energy from _____, but most energy originally comes from the sun. Plants are able to capture the sun’s energy and use it to produce glucose,________. This process, known as___________, occurs in the _________of plant cells. Ability to do work metabolic active Cell division homeostasis food C6H12O6 photosynthesis chloroplasts

The reaction for photosynthesis is: ______+______+__________________+_____ CO2 H2O Energy C6H12O6 O2

Plants and other organisms that can make their own food are known as ________________. Humans and other organisms that have to obtain food are known as ______________. Although glucose is the preferred energy molecule for the cell, other ___________, _______, and _______ can also be broken down for energy. autotrophs heterotrophs carbohydrates lipids proteins

B. Chemical Energy The chemical energy in food (and all molecules) is stored in the_____________. This is__________ energy. When the bonds are broken and the _________ are released, some energy is lost as ________, but a percentage of the potential energy can be converted to useable energy in the form of _____. Food molecules cannot be used as a direct energy source for the cell because food contains too much energy ... if it were released all at once, it would be _______ and ____________. chemical bonds potential electrons heat ATP wasteful destructive

C. ATP ___________________is a __________ that is composed of: ___________ - nitrogen base ___________ - 5 carbon sugar ___________________Groups Adenosine TriPhosphate nucleotide adenine ribose 3 phosphate

ATP - Adenosine Triphosphate. Has 3 phosphate groups. Energy is stored in __________________________. These “rechargeable batteries” are mostly present in the cell in two forms: ATP - Adenosine Triphosphate. Has 3 phosphate groups. ADP - Adenosine Diphosphate. Has 2 phosphate groups. Phosphate-phosphate bonds

_____ has the most phosphate bonds, and therefore contains the most ________ or stored energy. Cells are able to use and recycle ATP by breaking off or adding a _________ group. ATP potential phosphate

1. Energy can be used when a ________ bond is _________ 2. Energy is stored; that is, ATP is “recharged” by adding a phosphate group to ADP + P → ATP *Under normal conditions, both of these processes are occurring at the same time and all the time in a cell* phosphate broken ATP  ADP + P

REACTIONS of PHOTOSYNTHESIS Unit 4 http://vilenski.org/science/safari/cellstructure/chloroplasts.html REACTIONS of PHOTOSYNTHESIS Unit 4 http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

Research into PHOTOSYNTHESIS began centuries ago with this simple question: When a tiny seed grows into a huge plant, where does all the “new plant” come from? CO2 and H20 http://www.nofretete-page.de/gemischtNeu/TN_plant_grow_w.JPG

THE BIG PICTURE → sunlight Scientists discovered that in the presence of _________, plants transform CO2 and water into carbohydrates and release oxygen. sunlight Carbon dioxide WATER Sugars Oxygen _____________ + ____________ _______________ + ____________ 6 CO2 6 H2O → C6H12O6 6 O2 _____________ + ____________ _______________ + ____________

PHOTOSYNTHESIS: Reactants & Products LIGHT ENERGY 6CO2 + 6H2O SUGAR + 6O2

chlorophyll light energy In addition to water and , __________________ Carbon dioxide In addition to water and , __________________ and are needed for photosynthesis to happen. http://fig.cox.miami.edu/~cmallery/255/255phts/255phts.htm chlorophyll light energy

Chloroplast Found mainly in the _______ of most plants Disk-shaped organelles contain 2 main compartments Thylakoids- flattened ____________________ that are arranged in stacks, this is where the light-dependent rxn take place here. Grana- stacks of ____________ Stroma- __________________ that is outside the _______, this is where light-independent rxn takes place leaves saclike membranes thylakoids Fluid-filled spaces grana

Pigments- light ___________colored molecules absorbing thylakoid Found in __________ membranes Different pigments absorb specific _____________ of light ___________- ______most strongly in the ____________ region of the visible light spectrum & __________ light in the ______ region of the spectrum. (Why leaves appears green to our eyes) More abundant than other pigments in leaves, thus hides the colors of the other pigments. Different types called __________________ wavelengths Chlorophyll absorb Violet-blue reflect green Chlorophyll a & b

Accessory pigments- allows plant to _______ different __________ of light energy ______________- _________in _______________region &________, __________________________ Ex. β – carotene In fall production of ____________________slows down or stops, thus bringing out the colors of the accessory pigments. absorb wavelengths Carotenoids absorb Blue & green reflect Yellow, orange & red chlorophyll

http://son.nasa.gov/tass/images/cont_emspec2.jpg http://www.ology.amnh.org/einstein/lightmatterenergy/light.html

colors Visible light is made up of many different _______________of light Your eyes “see” different sizes of waves as different ___________ wavelengths colors http://www.simontucket.com/_Portfolio/PortLarge/L_Il_Prism.jpg

BUT… We “see” reflected light Light wavelengths that are ___________ off of objects bounce back to our eyes . That is the ___________ we “see” REFLECTED COLOR Image modified from: http://www.visibledreams.net/Web/color/color_3.html

ENERGY & ELECTRONS When chlorophyll absorbs light, the http://www.mhhe.com/biosci/pae/botany/uno/graphics/uno01pob/vrl/images/0160.gif When chlorophyll absorbs light, the energy is transferred to electrons in the chlorophyll molecule. HIGH ENERGY ____________ make photosynthesis work! ELECTRONS http://www.wjcc.k12.va.us/ROBB/Atom%20Animation%20Resources_files/image003.gif

PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS Proteins that are part of the thylakoid membrane organize ________________________________ into clusters called _____________________ Light absorbing PIGMENTS PHOTOSYSTEMS http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

LIVING THINGS NEED ENERGY CARRIERS Molecule that carries = _______ Molecule that carries HIGH ENERGY ELECTRONS = ___________ ATP NADP+ Images by Riedell

NADP ____________ is one of the carriers that cells use to transport Frying pan image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006 NADP ____________ is one of the carriers that cells use to transport high energy electrons. NADP+ ________ + _____ + _____ → ____________ 2 e- H+

LIGHT DEPENDENT REACTION Requires ______________ Molecules are part of ________________ Made up of __________________ connected by ______________________ & ___________________ Uses light energy to change ADP + P → _______ NADP+ + 2e- + H + → _________ Breaks apart ______ molecules and releases _____________ LIGHT THYLAKOID membranes PHOTOSYSTEMS II & I ELECTRON TRANSPORT CHAIN ATP SYNTHASE ATP NADPH H20 oxygen

LIGHT-DEPENDENT REACTIONS Pearson Education Inc; Publishing as Pearson Prentice Hall LIGHT-DEPENDENT REACTIONS SEE A MOVIE ATP SYNTHASE IN ACTION See an animation about the ELECTRON TRANSPORT CHAIN http://www.stolaf.edu/people/giannini/flashanimat/metabolism/atpsyn1.sw http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf

CALVIN CYCLE ____________ require ____________ (also called _________________________) ____________ require ____________ Happens in _________ between thylakoids NADPH donates _______________ ATP donates _________________ CO2 donates ______________ to make __________ LIGHT INDEPENDENT DOES NOT LIGHT STROMA Hydrogen + electrons ENERGY Carbon & oxygen GLUCOSE http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html

Calvin Cycle CO2 Enters the Cycle Energy Input 5-Carbon Molecules Regenerated 6-Carbon Sugar Produced See Calvin cycle animation Sugars and other compounds

PHOTOSYNTHESIS OVERVIEW Pearson Education Inc; Publishing as Prentice Hall