Respiration ReviewRespiration Review Fill in the blanks!Fill in the blanks!

A=2,A=2, B=3, B=3, C=4C=4 D=8D=8 E=32E=32

F=36F=36

************************************************************************************************************ Glycolysis makes ____ Glycolysis makes ____ NET ATPNET ATP and ______ and ______ (Intermediate Step) 2 pyruvate(Intermediate Step) 2 pyruvate 2 acetyl CoA 2 acetyl CoA

makes _____________makes _____________ Krebs Cycle makes ____________, _________, Krebs Cycle makes ____________, _________,

and _______and _______ ATP ATP

PhotosynthesisPhotosynthesis

6CO2 + 6 H20 6CO2 + 6 H20 C6H12O6 + 6O2 C6H12O6 + 6O2

Inside a leafInside a leaf

Chloroplasts are in cells of the Chloroplasts are in cells of the mesophyll, green tissue in the leaf’s mesophyll, green tissue in the leaf’s interiorinterior

CO2 enters and O2 exits the leaf thru CO2 enters and O2 exits the leaf thru pores called stomatapores called stomata

Stomata are controlled by guard cells Stomata are controlled by guard cells which can open and close themwhich can open and close them

LIGHT Dependent Reaction!LIGHT Dependent Reaction!

Takes place in the thylakoid (multiple Takes place in the thylakoid (multiple thylakoids= granum)thylakoids= granum)

Photons of light (energy units) strike a leaf Photons of light (energy units) strike a leaf and activate chlorophyll which will excite and activate chlorophyll which will excite electrons.electrons.

Activated chlorophyll molecule then Activated chlorophyll molecule then passes these excited electrons down to a passes these excited electrons down to a series of electron carriers to produce ATP series of electron carriers to produce ATP and NADPHand NADPH

Point of light reaction…make ATP + Point of light reaction…make ATP + NADPHNADPH

A bit about light…A bit about light…Sunlight is electromagnetic. It has a behavior that Sunlight is electromagnetic. It has a behavior that

is both wavelength and particle like…is both wavelength and particle like…

-The wavelengths are the distance between crests -The wavelengths are the distance between crests of electromagnetic wavesof electromagnetic waves

-Wavelengths that are absorbed disappear…what -Wavelengths that are absorbed disappear…what color would a pigment that absorbs all color would a pigment that absorbs all wavelengths be?wavelengths be?

-When white light which contains all wavelengths -When white light which contains all wavelengths of visible light illuminates a pigment, the color of visible light illuminates a pigment, the color you see is the color most reflected or transmitted you see is the color most reflected or transmitted by the pigmentby the pigment

Chlorophyll a + Chlorophyll b + Chlorophyll a + Chlorophyll b + carotenoidscarotenoids

-Chlorophyll a= only pigment that works -Chlorophyll a= only pigment that works directly and green in colordirectly and green in color

-Chlorophyll b=blue-green-Chlorophyll b=blue-green

-Cartenoids= yellow-orange…these -Cartenoids= yellow-orange…these have the ability to dissipate excessive have the ability to dissipate excessive light energy that would otherwise light energy that would otherwise damage chlorophylldamage chlorophyll

PhotosystemsPhotosystems

Chlorophyll a, b, and cartenoids are assembled Chlorophyll a, b, and cartenoids are assembled into photosystems within the thylakoid.into photosystems within the thylakoid.

Photosystems are light harvesting complexes.Photosystems are light harvesting complexes. Each photosystem has:Each photosystem has:

-Antenna complex-Antenna complex

-Reaction center chlorophyll-Reaction center chlorophyll

-Primary Electron Acceptor-Primary Electron Acceptor

Photosystem I and IIPhotosystem I and II

Photosystem I=has specialized Photosystem I=has specialized chlorophyll a molecule known as p700 chlorophyll a molecule known as p700

Photosystem II= has specialized Photosystem II= has specialized chlorophyll a molecule known as p680chlorophyll a molecule known as p680

They were named I and II because of the They were named I and II because of the order they were discovered, but order they were discovered, but photosystem II actually occurs before photosystem II actually occurs before photosystem I.photosystem I.

Noncyclic PhotophosphorylationNoncyclic Photophosphorylation produces produces ATP and NADPH using Photosystem I and II.ATP and NADPH using Photosystem I and II.

Step 1) P680 (photosystem II) captures light and Step 1) P680 (photosystem II) captures light and passes 2 excited electrons down an ETC to passes 2 excited electrons down an ETC to make ATP and then returned to P700make ATP and then returned to P700

Step 2) A molecule of water is split (Step 2) A molecule of water is split (photolysisphotolysis) ) by sunlight which releases….?by sunlight which releases….?

Step 3) P700 (photosystem I) captures light and Step 3) P700 (photosystem I) captures light and passes excited electrons down an ETC to passes excited electrons down an ETC to produce NADPHproduce NADPH

Chemiosmosis in Chemiosmosis in PhotosynthesisPhotosynthesis H+ ions accumulate in thylakoids…as H+ ions accumulate in thylakoids…as

photolysis occurs this releases H+ to the photolysis occurs this releases H+ to the inside of thylakoids (oxygen released inside of thylakoids (oxygen released outside) AND H+ accompany electrons as outside) AND H+ accompany electrons as they pass in the ETC between PS 1 and 2they pass in the ETC between PS 1 and 2

Similar situation as with chemiosmosis in Similar situation as with chemiosmosis in respiration…pH and electric gradient is respiration…pH and electric gradient is made, ATP synthase generates ATPmade, ATP synthase generates ATP

Reminder of What Chemiosmosis Is:Reminder of What Chemiosmosis Is: ChemiosmosisChemiosmosis is the diffusion of is the diffusion of ionsions across a across a

membranemembrane. More specifically, it relates to the . More specifically, it relates to the generation of ATP by the movement of generation of ATP by the movement of hydrogenhydrogen ions ions across a membrane. across a membrane.

Requires: Requires: a phospholipid bilayer, a proton pump, a phospholipid bilayer, a proton pump, protons and ATPaseprotons and ATPase

Chemical Energy is used to pump protons through a Chemical Energy is used to pump protons through a proton pump (intrinsic protein).  This creates a high proton pump (intrinsic protein).  This creates a high concentration of protons (H+). ATP synthase has a concentration of protons (H+). ATP synthase has a channel that allows for the facilitated diffusion of channel that allows for the facilitated diffusion of protons back in through the membrane which in turn protons back in through the membrane which in turn catalyzes the formation of ATP.catalyzes the formation of ATP.

Exists in respiration (in mitochondria) and Exists in respiration (in mitochondria) and photosynthesis (in chloroplasts)photosynthesis (in chloroplasts)

Cyclic PhosphorylationCyclic Phosphorylation Step 1) P700 (Photosystem 1) Step 1) P700 (Photosystem 1)

captures light and passes excited captures light and passes excited electrons down an ETC to make electrons down an ETC to make ATP…it’s much simpler.ATP…it’s much simpler.

Step 2) ATP is made BUT NADPH is Step 2) ATP is made BUT NADPH is NOT and water is NOT split by NOT and water is NOT split by sunlightsunlight

Why is this done? Calvin needs a Why is this done? Calvin needs a LOT of ATP, and this pathway is LOT of ATP, and this pathway is quick and another way to supplement quick and another way to supplement the ATP needed besides noncyclic. the ATP needed besides noncyclic.

ANIMATION: http://www.cst.cmich.edu/users/baile1re/bio101fall/enzphoto/photoanima.htm#

Calvin Cycle (Light Calvin Cycle (Light Independent, C3)Independent, C3)

This takes place in the stromaThis takes place in the stroma It will use what was made in light reaction It will use what was made in light reaction

(ATP, NADPH) to make SUGAR(ATP, NADPH) to make SUGAR Also, this is where the CO2 will be taken in. Also, this is where the CO2 will be taken in.

CO2 will be “fixed” in this cycle.CO2 will be “fixed” in this cycle. CO2 enters, and is combined with rubisco CO2 enters, and is combined with rubisco

(RuBP)(RuBP) 6 CO2+ 6 RuBP= 12 PGA (phosphoglycerate)6 CO2+ 6 RuBP= 12 PGA (phosphoglycerate)

12 ATP + 12 NADPH are used to convert 12 ATP + 12 NADPH are used to convert 12 PGA to 12 PGAL 12 PGA to 12 PGAL (phosphoglyceraldehyde) …basically what (phosphoglyceraldehyde) …basically what you’re doing is giving it more energy (from you’re doing is giving it more energy (from the ATP and NADPH)the ATP and NADPH)

2 of the PGAL is used to build glucose. 2 of the PGAL is used to build glucose. From glucose you can make fructose or OR From glucose you can make fructose or OR combine with disaccharides (like sucrose)combine with disaccharides (like sucrose)

10 of the PGAL is converted (by the help of 10 of the PGAL is converted (by the help of 6 ATP) to make 6 RuBP to allow the cycle 6 ATP) to make 6 RuBP to allow the cycle to repeat: (6 CO2+ 6 RuBP= 12 PGA )to repeat: (6 CO2+ 6 RuBP= 12 PGA )

Overall equation for Calvin Cycle Overall equation for Calvin Cycle was:was:

6CO2+ 18 ATP + 12 NADPH 6CO2+ 18 ATP + 12 NADPH 18 ADP + 18 Pi + 12 NADP+ 1 18 ADP + 18 Pi + 12 NADP+ 1

gulcosegulcose

The Problem of Photorespiration…The Problem of Photorespiration…

RuBP is one of the most common proteins RuBP is one of the most common proteins on Earth. A great thing for plants, but it’s on Earth. A great thing for plants, but it’s not so picky. It can fix CO2 but it also will not so picky. It can fix CO2 but it also will just as well fix O2. just as well fix O2.

Bright light can stunt the growth of C3 Bright light can stunt the growth of C3 plants. Why do you think this could be?plants. Why do you think this could be?

The specific name of this is called The specific name of this is called photorespirationphotorespiration which means it fixes which means it fixes oxygen. The products of this aren’t useful oxygen. The products of this aren’t useful so plant perioxisomes are often used to so plant perioxisomes are often used to help break them down.help break them down.

Added HelpAdded Help C4 Photosynthesis…an “add on feature” C4 Photosynthesis…an “add on feature”

that enhances CO2 fixation in areas that that enhances CO2 fixation in areas that are hot and would have lots of are hot and would have lots of photorespiration photorespiration

Carbon dioxide can combine with Carbon dioxide can combine with phoenolpyruvate (PEP) now instead of phoenolpyruvate (PEP) now instead of rubisco. It makes OAA (oxaloacetate) rubisco. It makes OAA (oxaloacetate) which is then converted to malate.which is then converted to malate.

Malate is like a bus that will deliver CO2 to Malate is like a bus that will deliver CO2 to specialized cells called the specialized cells called the bundle sheath bundle sheath cellscells. These cells are deeply packed and . These cells are deeply packed and not in contact w/ much O2not in contact w/ much O2

In the sheath cell, malate is converted into In the sheath cell, malate is converted into pyruvate and CO2..pyruvate is shuttled back pyruvate and CO2..pyruvate is shuttled back and ATP will convert it back into PEPand ATP will convert it back into PEP

CAM PHOTOSYNTHESIS:CAM PHOTOSYNTHESIS:-Similar to C4 photosynthesis EXCEPT the -Similar to C4 photosynthesis EXCEPT the

OAA is converted into malic acid (instead of OAA is converted into malic acid (instead of malate) and sent to a cell’s malate) and sent to a cell’s vacuolevacuole at night. at night. During the day, it converts back to During the day, it converts back to oxaloacetate and CO2 is released for oxaloacetate and CO2 is released for photosynthesisphotosynthesis

-Very useful for very dry environments. Cacti -Very useful for very dry environments. Cacti and succulents commonly do CAM and succulents commonly do CAM photosynthesisphotosynthesis

Why CAM Photosynthesis Why CAM Photosynthesis is Usefulis Useful

Most plants open stomata (leaf pores) in Most plants open stomata (leaf pores) in the day time to take in CO2. But CAM the day time to take in CO2. But CAM photosynthesis allows stomata to open at photosynthesis allows stomata to open at night (as these plants in dry night (as these plants in dry environments want to conserve water environments want to conserve water and do not want to lose water during the and do not want to lose water during the hot, sunny daytime)hot, sunny daytime)

Ultimate QuestionUltimate QuestionFor the following, pick (A) Photosynthesis, (B) For the following, pick (A) Photosynthesis, (B)

Respiration, or (C) both.Respiration, or (C) both.

1.1. Uses NAD+, an electron carrier.Uses NAD+, an electron carrier.2.2. Uses chemiosmosis to generate ATP.Uses chemiosmosis to generate ATP.3.3. Has a step that takes place in the thylakoid.Has a step that takes place in the thylakoid.4.4. Generates CO2 as a byproduct.Generates CO2 as a byproduct.5.5. Is endergonic.Is endergonic.6.6. Can be done by bacteria.Can be done by bacteria.7.7. Needs a proton (H+) pump.Needs a proton (H+) pump.8.8. A probe that measures oxygen could determine A probe that measures oxygen could determine

its rate.its rate.