Are You Ready?
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Page 176/177
 Complete
# 1, 2, and 4.
 Make sure you know # 1!!
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Are You Ready . . . #1
= Nucleus – overall control
 B = Cell Membrane – Protection
 C = Chloroplast – contains chlorophyll (where
photosynthesis occurs)
 D = Vacuole – water and nutrient storage
 E = Mitochondria – where cellular respiration occurs
(powerhouse of the cell)
 F = S.E.R. – associated with fat and oil production
 G = R.E.R. – has ribosomes
 H = Flagellum – movement
 I = Cell Wall – rigid frame around a PLANT cell.
 Not included in the Picture:
A

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Ribosomes- site of protein (amino acid) synthesis
Lysosomes- contain strong chemical that digest molecules
Unit C:
Photosynthesis and
Cellular Respiration
Chapter 6: Photosynthesis
http://www.teachertube.com/members/viewVideo.php?video_id=62625&tit
le=Photosynthesis
Electromagnetic radiation (EMR)
•Light is a type of EMR
•All EMR occurs in the form of individual packets of energy called photons
•Photons with short wavelengths have high energy and those with long
wavelengths have low energy
750nm
380 nm
harmful radiation
Photosynthesis - Overview

Simply looking at beginning and end
products



CO2(g) + H2O (l) + energy  C6H12O6 + O2(g)
Solar energy is the ultimate source of energy(for
everything?)
Review:



Name 3 groups that carry out photosynthesis.
Define light
What is a photon?
Review

Photosynthesis is carried out by who?
 These
organisms all contain what?
Chlorophyll
Chlorophyll absorbs photons from solar
energy and begins the process of
photosynthesis
 Chlorophyll a (blue green) and chlorophyll b
(yellow green) two common forms
 Chlorophyll a primary light-absorbing
pigment found in plants

Chlorophyll

Chlrorophylls a and b absorb photons with energies
in the blue-violet and red regions and reflect those in
the 500-600nm region (green)
Chlorophyll
 Chlorophyll
a is the only pigment that
can transfer the needed energy of
photosynthesis
 In the fall other colors are seen due to
chlorophyll being disassembled,
showing the accessory pigments such
as carotenoids and xanthophylls
Chloroplasts






Chlorophyll is found in chloroplasts
A typical chloroplast has ~60 grana, each has
~30-50 thylakoids.
Adjacent grana connected by unstacked
thylakoids called lamellae
Photosynthesis occurs in stroma and thylakoid
membrane
Thylakoid membrane contains light gathering
pigment molecules and electron transport chains
Thylakoid lumen – the fluid filled space inside a
thylakoid
Chloroplast Structure

Thickened regions
called thylakoids. A
stack of thylakoids is
called a granum.
(Plural – grana)

Stroma is a liquid
surrounding the
thylakoids.
Page 185
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# 1-4
Oxidation – Reduction Reactions
Oxidation – a reaction in which an atom or
molecule loses electrons
 Reduction- a reaction in which an atom or
molecule gains electrons


LEO goes GER
The Reactions of Photosynthesis
The Molecules Formed during Photosynthesis
Molecule
Function
ATP
Energy-supply molecule for cellular functions
Provides immediate sources of energy for cellular
processes (growth and movement)
NADPH
Electron donor involved in energy transfers
Glucose
Transport molecule
Medium term energy storage in most cells
ATP
ATP is formed by the addition of a nonorganic phosphate group to ADP. Can be
release with the reversal of this reaction.
 ADP + P + energy  ATP
 When phosphate(s) are added it is called
phosphorylation.

NADP+ and NADPH
NADP+ accepts one hydrogen atom and
two electrons to form NADPH
 NADPH can then donate electrons to other
molecules
 This contributes to photosynthesis . . .

Photosynthesis

Broken into different stages
 Stage

(light dependent reactions – occur on the thylakoid
membrane)
 Stage

2 –Electron Transfer and ATP synthesis
(light dependent reactions – occur on the thylakoid
membrane)
 Stage

1 –Capturing Solar Energy
3 – The Calvin Cycle and Carbon Fixation
(light independent reaction – occur in the stroma)
Stage 1: Capturing Solar Energy

Relies on two photosystems I and II (picture)
 Photosystem-
a cluster of phosynthetic pigments on the
thylakoid membrane
 Thousands found on every granum



Solar energy is captured when an electron in a
chlorophyll molecule absorbs a photon. This
excites the electron (giving it more energy)
The excited electron moves down the electron
transport chain (moving from PSII to PSI).
Electron transport chains allow the energy to be
released slowly
Electron Transport Chain (Stage 2)

As the excited electron moves down the
chain it releases energy, used to:
additional H+ into the thylakoid lumen.
 Building a positive charge in the lumen.
 pump
Once the electrons get to PSI they become
energized (sun) and two are transfer to
NADP+ with an H+ ion making NADPH.
 NADPH will be used in the Calvin Cycle
(stage 3).

Photolysis of water
This occurs at PSII
 Light breaks down H2O into H+, 4e- and O2(g).
 This replaces the electron that move into the
electron transport chain from P.S. II
 And releases Oxygen, and pushes H+ into the
thylakoid lumen
 Occurs in the Thylakoid lumen

Chemiosmosis
High concentration of H+ ions in the lumen
(positive charge)
 The H+ can only escape through ATP
synthases (on the thylakoid membrane)
 H+ rush through the ATP synthases
releasing energy, the ATP synthase uses
the energy to combine ADP with Pi
making ATP.

From the Light Dependent Reaction we
now have NADPH and ATP transferring on
to Stage 3.
 We also had O2 being released into the
atmosphere

Stage 3:
The Calvin Cycle and Carbon Fixation
Light independent reaction
 Uses ATP, NADPH (from light reactions) to
make G3P (a sugar used to make glucose)




One glucose molecule needs 6 CO2, 12 NADPH, 18 ATP.
Calvin Cycle requires CO2, it diffuses directly into the
chloroplasts from the atmosphere (through stomata)
G3P is used to make glucose and other carbohydrates
such as sucrose, cellulose and starch.

Diagram from Botany Notes, and Diagram
from page 193.
Concept Map
Photosynthesis
includes
Light
independent
reactions
Light
dependent
reactions
uses
Light
Energy
Thylakoid
membranes
to produce
ATP
NADPH
occurs in
occur in
Stroma
of
O2
Chloroplasts
uses
ATP
NADPH
to produce
Glucose
Cellular Respiration
Chapter 7
Objective

explain, in general terms, how glucose is
oxidized during glycolysis and the Krebs
cycle to produce reducing power in NADH
and FADH; and describe where in the cell
these processes occur
From photosynthesis we now have G3P,
or glucose.
 Cellular Respiration is a process that the
cells of animals and plants use to release
the energy stored in the bonds of glucose

The Beginning and The End …

C6H12O6 + O2(g)  CO2(g) + H2O (l) + energy

The Middle …
Intermediate products include:

 NADH,
FADH2, and ATP
 NADH – an electron carrier, donates electrons
 NAD+ - an electron carrier, accepts electrons
 FADH2 – an electron carrier, donates electrons
 FAD+ - an electron carrier, accepts electrons
 Their role is to transfer electrons through oxidationreduction reactions (releases energy)
Energy


Each time electrons
are transferred in
oxidation-reduction
reaction energy is
made available for
the cell to make ATP
~one billion ATP
molecules present in
a typical human cell.
Active Transport


Movement of substances through a membrane
against a concentration gradient using
membrane-bound carrier proteins and energy
from ATP.
The carrier proteins often called pumps
Sodium-Potassium Pumps – active transport pump
that pumps 3 sodium ions out for every 2 potassium
ions into the cell. Important to nerve cells and muscle
cells.
 Ex.
Functions
requiring ATP
Role of ATP
Examples
Motion
- Causes fibres (& muscle
fibres) within cells to
contract causing movement
Chromosome movement
Contraction of skeletal,
smooth, and cardiac
muscles
Transport of ions Powers active transport
and molecules
Sodium-potassium
pump
Hydrogen ion pump
Building
molecules
Provides energy for building Joining amino acids in
large molecules
protein synthesis
Switching
reactions on or
off
Alters shape of molecule,
changing it’s function
Bioluminescence Reactions with luciferin and
oxygen
Switches certain
enzymes on or off
Produces light (fireflies)
Glucose and ATP



ATP- is needed for virtually all cellular processes
Glucose- can’t be directly used, must be
converted in ATP
Glucose is used as storage as it is ideal for
transportation (because it is small and highly
soluble).
Energy
• It
takes energy to break bonds of
glucose, but it releases more energy
then is used.
•Primary role of cellular respiration
is to transfer energy in food into ATP
•This is not 100% efficient, only
about 36% of the energy is
converted. 64% lost as heat.
•Mammals and birds use this energy
to maintain their body’s warmth.
Page 209
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# 1-4
Two types of Cellular Respiration

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
The First Type:
Aerobic cellular respiration – in the presence of
oxygen end products are CO2(g), H2O, and 36 ATP
molecules
Occurs in the mitochondria
4
Stages:


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
Stage 1 – Glycolysis
Stage 2 – Pyruvate oxidation
Stage 3 - The Krebs cycle
Stage 4 - The electron transport chain and chemiosmosis
Two Types of Cellular Respiration


Type 2
Anaerobic cellular respiration – takes place in the
absence of oxygen
 Two



Stages
Stage 1: glycolysis
Stage 2: fermentation
Two types of anaerobic cellular respiration
represented by the following equations.
Glycolysis (STAGE 1)



Occurs in the cytoplasm of the cell
Glucose molecule is broken into two pyruvate
molecules (3 carbons each)
2 ATP needed to start reaction, 4 ATP are
produced thus the net gain is 2 ATP.
Aerobic Cellular Respiration
Pyruvate Oxidation (Stage 2)


End of stage one we had 2ATP’s, 2NADHs, 2 pyruvate molecules (in
the cytoplasm)
The pyruvate is transported through the two mitochondrial membranes
into the matrix then undergoes 3 changes:
1 – CO2 is removed from each pyruvate and released (waste)
 2 – NAD+ oxidizes the carbon portions remaining. NAD+ gains 2H+ ions
from pyruvate and the remaining carbon compound becomes an acetic
acid group
 3 – Coenzyme a (CoA) attaches to the acetic acid group, forming acetylCoA, moves to Stage 3 The Krebs Cycle.


Now we have CO2 diffuse out of the mitochondria as waste, two
molecules of NADH proceed to stage 4 (electron transport and
chemiosmosis), and acetyl-CoA entering the Krebs cycle.
Stage 3: The Krebs Cycle



A cyclic (8 step process) series of reactions that
transfers energy from ATP, NADH, and FADH2,
and removes carbon atoms as CO2.
Occurs twice for each molecule of glucose (due
to two acetyl-CoA that are produced)
By the end of the cycle we see all 6 Carbon
atoms from glucose have been oxidized to CO2
and released. 2ATP have been produced, 6
NADH, 2 FADH2.
Objective

explain, in general terms, how
chemiosmosis converts the reducing
power of NADH and FADH to store
chemical potential energy as ATP; and
describe where in the mitochondrion these
processes occur
Stage 4: Electron Transport and
Chemiosmosis



Electron carriers (NADH, and FADH2) loaded with
electrons and protons from the Kreb’s cycle move
to this the electron transport chain-like a series of
steps (staircase).
As electrons drop down stairs, energy released to
form a total of 32 ATP
Oxygen waits at bottom of staircase, picks up
electrons and protons and in doing so becomes
water
Electron Transport



The NADH carries electrons to the transport
chain, where protein complex’s take the
electrons and are passed along carrier
molecules, energy that is released is used to
pump H+ into the intermembrane space. Builds
up a positive charge.
The electrons are finally accepted by oxygen
molecules. (forms water)
FADH2 works in a similar fashion only less H+ is
pumped into the intermembrane space.
Chemiosmosis




ETC – forms an H+ ion gradient across the inner
mitochondrial membrane. This energy is used in
chemiosmosis to make ATP.
Higher positive charge in the intermmbrance
space than in the matrix
The H+ protons are forced to pass through an
ATP synthase (a special proton channel).
As the H+ moves through the ATP synthase
complex, energy is released driving the
synthesis of ATP from ADP and Pi.




NADH – pumps enough H+ into inner membrane
to make 3ATP’s
FADH2 pumps enough H+ to make 2ATP’s
The energy released in the ETC results from a
series of oxidation reactions resulting in ATP –
called oxidative ATP synthesis.
Now ATP can be used for cellular processes.
The Energy Sheet

Page 212 # 2, 3
Page 220
 Work on # 1, 2, 4, 5, 6, 7, 9, 10.

Objective

distinguish, in general terms, between aerobic and
anaerobic respiration and fermentation in plants, animals
and yeast summarize and explain the role of ATP in
cellular metabolism; e.g.,






active transport
cytoplasmic streaming
phagocytosis
biochemical synthesis
muscle contraction
heat production.
Anaerobic Cellular Respiration

Two Stages





Stage 1: glycolosis – already covered.
Stage 2: Fermentation- uses products of glycolosis with either
ethanol or lactic acid being the final waste product
No oxygen used= ‘an’aerobic
Results in no more ATP, final steps in these pathways
serve ONLY to regenerate NAD+ so it can return to pick
up more electrons and hydrogens in glycolysis.
End products such as ethanol and CO2 (single cell fungi
(yeast) in beer/bread) or lactic acid (muscle cells)
Alcohol Fermentation
2 Pyruvate converted to 2 acetaldehyde,
generating carbon dioxide, ethanol and
NAD+
 Ethanol is used in alcoholic beverages
 It also recycles NAD+ allowing glycolysis to
continue.
 Only 2 ATP produce in glycolysis, enough
for an organism to survive.

Importance of Alcohol
Fermentation

Breads, pastries, wine, beer, liquor and
soy sauce are all produced using
fermentation
Lactic Acid Fermentation
Fermentation occurring in animal cells.
 NADH transfers its hydrogen atoms to
pyruvate, making NAD+ and lactic acid.
 It also recycles NAD+ allowing glycolysis to
continue.

Lactic Acid
Accumulation of lactic acid molecules in
muscle tissue causes stiffness, soreness
and fatigue
 When exercise stops lactic acid is
changed back to pyruvate, requires extra
oxygen (call this the oxygen debt) and is
why we pant.
 Allows pyruvate to continue through
aerobic respiration
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Page 228
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# 1, 2, 3,
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Page 222 -- Work on # 1-3.
Page 222
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Read page 222.

? VO2 Max . . .