CELL ENERGY

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CELL ENERGY

• PHOTOSYNTHESIS CELLULAR RESPIRATION

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All Cells Need Energy

• Cells need energy to do a variety of work
• Making new molecules (whats this called?)
• Building membranes and organelles
• Moving molecules in and out of the cell
• Movement

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Most Missed Midterm Question!

• The bodys preferred energy source is ____.
• A. Lipids
• B. Proteins
• C. Nucleic Acids
• D. Carbohydrates
• Correct answer D Carbohydrates!
• Carbohydrates are easiest to be broken down to
  recharge ATP!!!
• Truly the answer is ATP.

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What energy sources can you think of?

• Cars Gasoline
• Cell Phone Battery
• TV Electricity
• Human Food
• http//ed.ted.com/lessons/the-simple-but-fascinati
  ng-story-of-photosynthesis-and-food-amanda-ooten

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Energy Flow

• 2 types of energy reactions
• ENDERGONIC
• Require an INPUT of energy (stores E)
• Build/Repair tissues
• Cell reproduction
• EXERGONIC
• Release energy
• Chemical reactions of the body give off E
• Ex. Muscle contraction
• Heat is released - EXERcise

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Where Does A Cell Get Energy?

• Food is broken down to a form the cell can use
  (glucose).
• Extra energy is stored in an ATP molecule.

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How is ATP/ADP Like a Cell Phone Battery?
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What Is ATP?

• ATP adenosine triphosphate is a molecule made
  up of
• 1 Adenine (NH group amine group)
• 1 Ribose Sugar
• 3 phosphate groups

Adenine
phosphate groups
Ribose
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How Does ATP Work?

• Energy is stored in the bond between the second
  and third phosphate group.
• When the bond is broken, energy is released and
  ADP is formed.

Adenine
Ribose
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• 9.1 ATP

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Lets look at ATP and see how it works

• LAB TIME Cell Energy/ATP Lab

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ATP Energy Currency

• Within a cell, formation of ATP from ADP and
  phosphate occurs over and over, storing and
  releasing energy.
• As the cell uses energy, ATP breaks down
  repeatedly to release energy and form ADP and
  phosphate.

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Adrenaline Rush.It must be my cAMP!
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MAKING USING Energy

• AUTOTROPHS
• - BANK ATP in food photosynthesis
• Release ATP from food cellular respiration

• HETEROTROPHS
• ACQUIRE BANKED ATP eating
• Release ATP from food cellular respiration

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MAKING USING Energy

• PHOTOSYNTHESIS
• Endergonic stores energy
• Takes place in cells with chloroplasts
• Cellular respiration
• Exergonic releases energy
• Takes place in all living cells
• Takes place in mitochondria

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What level do we know things?
The What
The How
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9.2 Photosynthesis

• Trapping light energy (sun) and converting it to
  chemical energy (carbohydrate which one?)
• Happens where?

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Photosynthesis

• Using light from the sun, plants combine water
  and carbon dioxide to make sugar .

• General Equation
• 6CO2 6H2O energy ? C6H12O6 6O2
• Reactants Products

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WHAT EXACTLY IS LIGHT?

• Light visible spectrum
• E travels in packets called photons
• These photons travel in waves
• The amount of energy in each packet depends on
  the wavelength (?)

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The electromagnetic spectrum
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WHAT EXACTLY IS LIGHT?
?
?

• Short ? ____ E _____ frequency
• Long ? _____ E ____ frequency
• ?s range (for visible light) 400-700nm
• (violet-red)
• Molecules can either _______ the entire photon or
  not (______)

?
?
absorb
reflect
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Figure 10.7 Determining an absorption spectrum
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Why leaves are green interaction of light with
chloroplasts
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How do plants capture light?

• Plants have 2 light-capturing pigments
• 1. Chloroplasts Chlorophyll
• Absorb red, blue
• Reflect 500-600nm (green)
• 2. Carotenoids
• Absorb light blue, green
• Reflect yellow, orange, red

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The structure of the chloroplasts

• Each is surrounded by a double-membrane envelope
• Thylakoid
• Stroma
• Grana
• The pigment is chlorophyll
• Comes in 2 forms
• Chlorophyll A and Chlorophyll B

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Photosynthesis

• Sets of Reactions (steps)
• 1. Light Reactions
• Light dependent
• 2. Calvin Cycle (Melvin Calvin)
• Light independent
• dark reactions

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1. Light Reactions

• Occurs in the grana/thylakoids chlorophyll
• Light E ? Chemical E (ATP)

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1. Light Reactions

• 1. Light absorbs into 2 reaction centers
• 680nm 700nm
• (photosystem II) (photosystem I)
• 2. Electrons are energized excited by light

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Excitation of chlorophyll by light
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1. Light Reactions

• 1. Light absorbs into 2 reaction centers
• 680nm 700nm
• (photosystem II) (photosystem I)
• 2. Electrons are energized excited
• 3. P680 energy splits H2O Releases H O
• 4. Excited e-s convert ADP to ATP
• 5. P700 e-s convert NADP to NADPH
• NADP is a carrier molecule (used in dark
  reactions)

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http//www.cst.cmich.edu/users/baile1re/bio101fall
/enzphoto/photoanima.htm
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Photosystems

• Light harvesting units of the thylakoid membrane
• Composed mainly of protein and pigment antenna
  complexes
• Antenna pigment molecules are struck by photons
• Energy is passed to reaction centers
• e-s are excited and passed through an electron
  transport system
• A series of proteins in the thylakoid membrane

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Electron Transport

• photons excite chlorophyll e-
• e-s travel to Photosystem I down an electron
  transport chain
• as e-s fall, ADP forms ATP

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1. Light Reactions

• Light Reactions Summary
• Light energy is converted to chemical energy to
  split hydrogen from water.
• Takes place in the grana of the chloroplasts (the
  coin-like stacks of thylakoids).
• Byproducts are
• Oxygen waste
• NADPH/ATP used in the dark reactions

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Part 2 of PhotosynthesisLight Independent
(dark) reactions
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2. Light Independent Reactions

• Calvin Cycle
• ATP and NADPH from the light reactions are used
  along with CO2 to form a simple sugar (glucose).
• Takes place in the stroma of the chloroplasts
  (the liquid filling).
• Byproducts are
• C6H12O6 (glucose)
• ADP and NADP (which return to the light
  reactions).

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http//highered.mcgraw-hill.com/sites/0070960526/s
tudent_view0/chapter5/animation_quiz_1.html
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The Calvin cycle

• 3 molecules of CO2 are fixed into
  glyceraldehyde 3-phosphate (G3P)
• Phases 1- Carbon fixation each CO2 is
  attached to RuBP (rubisco enzyme)
• 2- Reduction electrons H from NADPH reduces
  to G3P ATP used up
• 3- Regeneration G3P rearranged to
  RuBP ATP used cycle continues

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Calvin Cycle, net synthesis

• For each G3P (and for 3 CO2). Consumption of
  9 ATPs 6 NADPH (light reactions regenerate
  these molecules)
• G3P can then be used by the plant to make glucose
  and other organic compounds
• Carbohydrates!

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Figure 10.17 The Calvin cycle (Layer 1)
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Figure 10.17 The Calvin cycle (Layer 2)
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Figure 10.17 The Calvin cycle (Layer 3)
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Sunlight
O2
Photosystem I II
H2O
ATP
NADP ADP
NADPH
CO2
Calvin cycle
Glucose
CHLOROPLAST
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Photosynthesis an overview

• H2O is split, e- (along w/ H) are transferred to
  CO2, reducing it to sugar
• 2 major steps
  
• light reactions (photo) energy made
• NADP (electron acceptor) to NADPH
• Photophosphorylation ADP ---gt ATP
• Calvin cycle (synthesis) carbohydrate is
  made
• Carbon fixation carbon into sugars
• http//www.stolaf.edu/people/giannini/flashanimat/
  metabolism/photosynthesis.swf

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Photosynthesis

• Using light from the sun, plants combine water
  and carbon dioxide to make sugar .

• General Equation
• 6CO2 6H2O energy ? C6H12O6 6O2
• Reactants Products

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Tracking atoms through photosynthesis
Released Oxygen came from Water!!!!
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Desert Plant Adaptation

• -Plants must conserve H2O
• -Opening stoma on leaves of plant CO2 BUT water
  diffuses out!
• -Hot/dry days - stomata close CO2 decrease, no
  ATP or food generated
• Solution..

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Alternative carbon fixation methods, II

• CAM plants open stomata during night, close
  during day (crassulacean acid metabolism) cacti,
  pineapples, etc.
• Less water loss
• Photo (day) store energy
• Synthesis (night) make sugar

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• Post Lecture Questions Answer on separate sheet
• 1. What is the equation for photosynthesis?
• 2. What are the reactants of the light reactions?
  
• 3. What are the products of the light reactions?
• 4. What is the purpose of NADPH and ATP in
  photosynthesis?
• 5. What are the reactants of the
  light-independent reactions (Calvin Cycle)?
• 6. What are the products of the light-independent
  reaction (Calvin Cycle)?
• 7. Which step of photosynthesis is exergonic?
• 8. Which step of photosynthesis is endergonic?

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Formative Review

• Summarize the 2 reactions (Light Dark/Calvin)
  using the following words
• Light
• CO2
• ADP
• NADP
• NADPH
• Water
• ATP
• Carbohydrate
• e-
• H

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Formative Review Example

• In the light reactions, water is split using the
  energy from light. Light excites the electrons
  from water, which catalyze the reaction of ADP
  back to ATP. The H atoms and e from water are
  then picked up by the electron carrier molecule
  NADP which becomes NADPH and taken to the Calvin
  Cycle.
• In the Calvin Cycle, the e- and H from NADPH are
  added to CO2 using the energy from ATP to build a
  carbohydrate.

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Switch it, Grade it

• Every word used right (correctly in the right
  step) is 10 pts only count once
• What did they score?

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Nutrient adaptation

• Nutrients necessary for plant health
• ATP, NADPH contain Nitrogen, Phosphorous (common
  in fertilizer)
• Carnivorous plants seeking nutrients!

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Photosynthesis the BIG picturePlants in
SPACE?!?!
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• 5.3 Cellular Respiration Harvesting Chemical
  Energy to Make ATP

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How can cells replenish ATP?

• CELLULAR RESPIRATION
• uses food and breathing to make E
• (glucose) (oxygen) (ATP)
• ? THE GENERAL EQUATION
• C6H12O6 6O2 38ADP 38Pi ?
• 6CO2 6H2O 38ATP

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How can cells replenish ATP?

• BUT
• To break the glucose we use 2 ATPs so what is
  the net ATP from cellular respiration?
• NOTE Some energy is lost by heat
• Cellular Respiration takes the energy in glucose
  to make ATPs
• Aerobic Respiration Using oxygen to make Energy

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Cellular Respiration

• 3 Steps
• Glycolysis
• Citric Acid Cycle
• Electron Transport Chain
• Also called oxidative phosphorylation

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Cellular Respiration STEP 1

• Glycolysis
• Oxygen is NOT required!
• Glucose is split to form pyruvate.
• Takes place in the cytoplasm of the cell.
• ATP is a byproduct.
• http//www.science.smith.edu/departments/Biology/B
  io231/

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Cellular Respiration STEP 1

• Glycolysis
• Glucose 2ATP 2NAD ?2 Pyruvic Acid 4ATP
  2NADH
• (pyruvate)
• Not very efficient to make more ATP cells must
  move on to step II and III (only if O2 is
  present)
• NAD Coenzyme which carries electrons (Hs) to
  make NADH (used later to make ATP)

Why is this only 2 ATP?
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Cellular Respiration STEP 1

• Pyruvate now moves into the mitochondria step 2

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Cellular Respiration STEP 2

• Citric Acid Cycle (Krebs)
• Pyruvate is used to build citric acid (a carbon
  compound), which is broken down to release ATP.
• Takes place in the cristae (the folded membrane
  in the mitochondrion).
• CO2 is released
• NADH FADH2 carry hydrogen ions electrons to
  the electron transport chain (step 3)
• http//www.science.smith.edu/departments/Biology/B
  io231/

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Mitochondrion
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Cellular Respiration STEP 2

• Citric Acid Cycle (Krebs cycle)
• Pyruvic acid oxidizes (breaks) into Acetyl-CoA
• happens PRIOR to the cycle
• Also made NADHs, FADH2, GTP (converts to ATP)

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Formation of Acetyl CoA
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Cellular Respiration STEP 2

• CITRIC ACID CYCLE
• 2-C (acetyl-coA) 4-C (oxaloacetic acid) 6-C
  (citric acid)
• The 4-C molecule is recycled
• Releasing 2 Cs as.
• Cycle turns twice WHY?

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Cellular Respiration STEP 3

• Electron Transport Chain
• H ions are stripped of their energy large
  amounts of ATP are formed.
• Takes place in the inner membrane of the
  mitochondrion.
• The used ions are combined with oxygen to form
  H2O.
• Also called oxidative phosphorylation
• http//www.science.smith.edu/departments/Biology/B
  io231/

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Cellular Respiration STEP 3

• Electron Transport Chain
• e- energy pumps H to intermembrane space
• H concentration gradient builds
• NADH and FADH2 pass electrons (Hs) to water
• Flow of H to matrix through ATP synthase protein
  channel ? ADP into ATP (34)
• H and O make H2O

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Cellular Respiration SUMMARY
Glycolysis Citric Acid Cycle Electron Transport
USES
MAKES
OCCURS
ATP
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Cellular Respiration SUMMARY
Glycolysis Citric Acid Cycle Electron Transport
USES Glucose ATP (2) NAD
MAKES NADH ATP (4) 2 pyruvate
OCCURS Cytoplasm
ATP 2 NET (4 gross)
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Cellular Respiration SUMMARY
Glycolysis Citric Acid Cycle Electron Transport
USES Glucose ATP (2) NAD Pyruvate (2) ?Acetyl Co-A (2)
MAKES NADH ATP (4) ATP CO2 NADH FADH2
OCCURS Cytoplasm Inner membrane of Mitochondria
ATP 2 NET (4 gross) 2 (1 for each Acetyl-coA)
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Cellular Respiration SUMMARY
Glycolysis Citric Acid Cycle Electron Transport
USES Glucose ATP (2) NAD Pyruvate (2) ? Acetyl Co-A (2) NADH FADH2 O2
MAKES NADH ATP (4) CO2 NADH FADH2 H2O ATP (32)
OCCURS Cytoplasm Inner membrane of Mitochondria Inner membrane of Mitochondria
ATP 2 NET (4 gross) 2 (1 for each Acetyl-coA) 32
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Cellular Respiration SUMMARY

• C6H12O6 6O2 ? 6CO2 6H2O Energy
• (glucose) (breath) (used in photosyn.)
  (ATPs)

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http//www.science.smith.edu/departments/Biology/B
io231/
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Heat
Electron Transport System
O2
ATP
H2O
NADH
NAD
CO2
citric acid cycle
Glucose
ATP
Pyruvate
MITOCHONDRION
ATP
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Sunlight
Heat
O2
Photo- System I
Photo- system II
Electron Transport System
ATP
H2O
ATP
NADP ADP
NADPH
NAD
NADH
CO2
Calvin
Citric Acid
Cycle
Cycle
ATP
Glucose
Pyruvate
CHLOROPLAST
MITOCHONDRION
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Sunlight
Heat
O2
Photo- System I
Photo- system II
Electron Transport System
ATP
H2O
ATP
NADP ADP
NADPH
NAD
NADH
Calvin
CO2
Cycle
Citric Acid
Cycle
ATP
Glucose
CHLOROPLAST
MITOCHONDRION
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Cellular respiration
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Energy efficiency

• Cellular respiration- 40
• Gasoline powered engine- 25

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What if O2 is not present?

• Anaerobic Respiration
• Making E without oxygen
• Glycolysis can still occur
• Its an ANAEROBIC AEROBIC process
• This is NOT efficient enough why?
• Two types of respiration occurring without
  oxygen
• Lactic Acid Formation
• Fermentation

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What if O2 is not present?

• Lactic acid fermentation in muscles
• When O2 runs out, but glucose is still starting
  to break down into pyruvate
• C6H12O6 4ADP 4Pi? 2CH3CHOHCOOH 4ATP
• (lactic acid/lactate)
• Note the ATP difference
• Converts pyruvate to lactate (lactic acid)

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What if O2 is not present?

• Alcoholic fermentation in plants (foods)
• Makes CO2 and ethanol (an alcohol)
• C6H12O6 4ADP 4Pi ? 2C2H5OH 2CO2 4ATP
• (ethnaol)
• Converts pyruvate to lactate (lactic acid)

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