Chapter 3 Biochemical Processes in cells Slide 2 Chemical Energy
in organic compounds reading p. 62 Living organisms require energy
in the form of organic compounds to survive Heterotrophs (= other
feeding) Rely on an external energy source Uses organic matter from
dead and living organisms or their products to obtain carbon
Autotrophic organisms (= self feeding) build organic compounds from
simple inorganic compounds such as carbon dioxide and water. Use an
external source of energy, usually the sun, to build organic
compounds. Slide 3 When organic compounds react to form products
with lower energy, such as inorganic compounds, energy is released
(see figure 3.5). Some of this energy is available as chemical
energy and some is released as heat energy. In every reaction that
involves either the transfer or transformation of energy, some
always appears as heat energy. We (will) consider two types of
energy reactions, those releasing energy and those requiring
energy, using the terms exergonic (catabolic) and endergonic
(anabolic) respectively. Exergonic reaction is oxidation. Oxidation
reactions involve the addition of oxygen to a substance. Oxidation
reactions are controlled by catalysts or enzymes. Under control of
enzymes, reactions occur at temperatures and rates that can sustain
the living state. Example: oxidation of glucose through
respiration. Exergonic & Endergonic Reactions reading p. 62
Slide 4 break down macromolecules into smaller molecules, releasing
energy in the form of ATP (and heat) for use by the organism occur
when large molecules are broken down into smaller ones rate of
reactions controlled by enzymes in living cells under control of
enzymes, reactions occur at temperatures and rates that can sustain
the living state. Drawing: Figure 3.7 Example: oxidation of glucose
in respiration Oxidation reactions involve the addition of oxygen
(or removal of electrons from) to a substance. Oxidation reactions
are controlled by catalysts or enzymes. Exergonic (Catabolic)
Reactions reading p. 62-64 Slide 5 Require energy endergonic
reactions are also known as anabolic reactions. Occur when a cell
makes large molecules from smaller molecules Examples: DNA
synthesis from nucleotides, Photosynthesis. Reduction reactions are
endergonic and involve the removal of oxygen from organic
compounds. See table 3.1 page 64 Drawing Endergonic (Anabolic)
Reactions reading p. 62-64 Slide 6 The change in energy from
initial state to final state is referred to as G. Exergonic
reactions release energy. Endergonic reactions require the input of
energy. (a) (b) Slide 7 In Your Books 1. Use selected examples to
explain the difference between exergonic and endergonic reactions.
Exergonic reactions involve a release of energy. These occur when
the chemical bonds in molecules are broken. E.g. Cellular
respiration. Endergonic reactions require an input of energy. These
are reactions in which larger molecules are constructed from
smaller ones, by forming chemical bonds. E.g. Photosynthesis. Slide
8 8 Energy is required to form bonds. Atoms or molecules Energy +
Energy Larger molecule The energy that was used to form the bonds
is now stored in this molecule. Slide 9 ATP as the energy currency
of cells Living cells do not have direct access to the energy
stored in organic molecules Organic molecules must be broken down
into smaller molecules to release their energy The energy released
from such reactions is used to produce ATP (Adenosine Triphosphate)
from ADP (Adenosine diphosphate) ATP is formed when energy is
released during cellular respiration of glucose. Slide 10 10 CH N C
C C NH 2 N HC N N C C C C O C O P O P O P O CH 2 O O O O - O - O -
- H OH H ATP (Adenosine Triphosphate) 3 phosphate groups Base
(adenine) Ribose Slide 11 11 ATP (Simplified Drawing) A Base
(adenine) Sugar (ribose) 3 phosphate groups Slide 12 12
Phosphorylation ATP is synthesized from ADP + P i. The process of
synthesizing ATP is called phosphorylation. Slide 13 Figure 2 This
is the two-dimensional structure of ATP, adenosine triphosphate.
The removal of one phosphate group (green) from ATP requires the
breaking of a bond (blue) and results in a large release of free
energy. Removal of this phosphate group (green) results in ADP,
adenosine diphosphate. Interesting Fact: In a typical cell, an ATP
molecule is used within a minute of its formation. ATP as the
energy currency of cells copy Slide 14 14 A ATP ATP Stores Energy
This phosphate bond is a high-energy bond A Energy ADP + P i +
Energy Breaking the bond releases the energy. Slide 15 15 ATP ADP +
P i Energy (from glucose or other high-energy compounds) ATP is
Recycled copy ATP (Adenosine Triphosphate) is an energy-containing
molecule used to supply the cell with energy. The energy used to
produce ATP comes from glucose or other high-energy compounds. ATP
is continuously produced and consumed as illustrated below. ADP + P
i + Energy ATP + H 2 O (Note: P i = phosphate group) Slide 16 ATP /
ADP Cycle The usable energy of ATP is contained in its three
phosphate bonds. Usually the energy from only one bond is released
for biologically useful work. The resulting ADP (adenosine
diphosphate) is recycled using energy derived from the breakdown of
glucose. Formula: ATP ADP + Pi (+ 60% as heat) Task Biozone p.44
Slide 17 17 Energy Supplied Energy Released Anabolic Reactions
Anabolic reactions consume energy. Substrates (Reactants) Products
Menu Slide 18 18 Energy Supplied Energy Released Catabolic
reactions release energy. Catabolic Reactions Substrate (Reactant)
When bonds are broken, energy is released. Menu Slide 19 ENZYMES
Slide 20 Enzymes reading page64-67 are proteins that act on other
molecules are organic catalysts are protein molecules that increase
the rate of reactions that occur inside the organism. are generally
intracellular (exception: digestive enzymes) some require a
non-protein cofactor (i.e vitamins, CoQ10) before they can act have
a region, known as the active site, that alligns with a particular
substrate the compounds obtained as a result of the enzyme action
are called the products enzymes are highly specific in their
action. Each enzyme acts on a particular substrate. Diagram Slide
21 Substrate Enzyme Active Site Enzyme-Substrate Complex Product
Enzyme 1 2 3 Enzymes Enzymes are organic catalysts. Menu Slide 22
22 Enzymes Catalysts are substances that speed up chemical
reactions. Organic catalysts (contain carbon) are called enzymes.
Enzymes are specific for one particular reaction or group of
related reactions. Many reactions cannot occur without the correct
enzyme present. They are often named by adding "ase" to the name of
the substrate. Example: Dehydrogenases are enzymes that remove
hydrogen. Slide 23 Enzyme Action lock and key theory Reading p65-66
This complementary fitting of shapes is known as the lock and key
theory of enzyme action. See figure 3.10a Slide 24 Enzyme Action
induced fit theory Reading p65-66 in some cases, the shape of the
active site varies slightly from that of the substrate and the two
fit only after the substrate induces a complimentary shape at the
active site theory of enzyme action. The induced-fit theory assumes
that the substrate plays a role in determining the final shape of
the enzyme and that the enzyme is partially flexible. Slide 25
Enzyme Action poisons such as cyanide and arsenic, block the active
sites of enzymes to prevent them from working. enzymes are
typically named for their substrates: Maltase works on maltose
Lipases works on lipids Amylase works on amylose DNA ploymerase the
ase ending tells us that it is an enzyme. Task Biozone p.37-38
Slide 26 Factors Affecting Enzyme Action reading p.67-68 each
enzyme: has optimal conditions of pH and temperature for its action
may be unable to combine with its substrate if pH is not optimal
may be denatured if the temperature rises above the optimal enzymes
in human cells work best at pH 7.6 and at 37.4 o c absence of a
co-factor may prevent or inhibit enzyme action rate of reaction
will be dependent upon amount of: substrate concentration enzyme
concentration cofactors concentration presence of inhibitors such
as poisons Tasks Quick Check 1-5 p.68 Biozone 39-40 Slide 27
Factors Affecting Enzyme Action Enzyme Concentration By increasing
the total amount of enzyme present, the amount of product made by
unit-time will increase. Substrate Concentration The addition of
more substrate increases the amount of product made, but does not
affect the rate of a reaction. Slide 28 Factors Affecting Enzyme
Action Inhibition Another substance may compete with the normal
substrate. This causes the intruder to block the active site of the
enzyme and not allow the substrate to combine. Enzyme inhibition
can cause death. Slide 29 ATP as the energy currency of cells
Living cells do not have direct access to the energy stored in
organic molecules Organic molecules must be broken down into
smaller molecules to release their energy The energy released from
such reactions is used to produce ATP (Adenosine Triphosphate) from
ADP (Adenosine diphosphate) ATP is formed when energy is released
during cellular respiration of glucose. Task Biozone p.44 Slide 30
Ecosystem Trophic Levels Plants provide the worlds organisms with
food Slide 31 Photosynthesis Slide 32 Photosynthesis is the process
by which plants produce their own food takes place in chloroplast
6CO 2 + 6 H 2 O + light C 6 H 12 O 6 + 6O 2 Slide 33 Chloroplast
Organellephotosynthesis Organelle where photosynthesis takes place.
Granum Thylakoid Stroma Outer Membrane Inner Membrane Slide 34
Thylakoid Thylakoid Membrane Thylakoid Space Granum Slide 35 Slide
36 Site of Photosynthesis takes place in chloroplast Slide 37
Chloroplasts reading pages 69-71 are (double) membrane-bound
organelles found in the cytosol of (some) plant and algal cells are
the site of photosynthesis internal membranes (thylakoid membrane)
forms disks called grana stack of grana membranes are called granum
the fluid surrounding the thylakoid membrane inside the
chloroplasts is called the stroma and contains enzymes are not
found in every plant cell! Copy figure 3.16 Task Quick check
6-8p.71 Slide 38 Chlorophyll (& Carotenoids) is a photon
trapping pigment trapping red and blue-violet light comes in two
kinds (chlorophyll a & b) reflect green light (carotenoids
absorb blue-violet light and appear orange yellow or red) Slide 39
Chlorophyll Molecules thylakoid membranes Located in the thylakoid
membranes. Mg + Chlorophyll have Mg + in the center. Chlorophyll
pigments absorbingwavelengthsblue-420 nm Chlorophyll pigments
harvest energy (photons) by absorbing certain wavelengths (blue-420
nm and red-660 nm are most important). Plantsgreen
wavelengthreflectednot absorbed Plants are green because the green
wavelength is reflected, not absorbed. Slide 40 Describing
Photosynthesis in brief reading pages 69-71 is light dependent and
involves the trapping of sunlight (radiant energy) by pigments such
as chlorophyll by producer organisms is the process of converting
the energy of sunlight to chemical energy the raw materials are
carbon dioxide and water, and the products are carbohydrate and
oxygen. In plants and algae, photosynthesis occurs in the organelle
chloroplasts light (photons) 6CO 2 + 12H 2 0 C 6 H 12 O 6 + 6O 2 +
6H 2 O *new water! chlorophyll Examine diagram page 69 Task Biozone
page 45, 49 Slide 41 Photosynthesis Overview A bit simplified and
we will slightly change this equation momentarily! More detail is
required, but first. Slide 42 Question: Why are plants green? Why
are plants green? Slide 43 Why Plants are Green? Slide 44 Slide 45
Absorption of Chlorophyll wavelength Absorption violet blue green
yellow orange red Slide 46 Slide 47 Slide 48 Two Stages in
Photosynthesis reading pages 72 The word photosynthesis is made up
of two parts: photo = light and synthesis = put together. The name
reflects the two-stage nature of the process. Stage One: a light
dependent stage involving trapping energy of light (in grana) Stage
Two: a light independent stage, known as carbon reduction (in
stroma) Slide 49 Light vs. Dark Reactions Energy & Reducing
Power Slide 50 50 Electron Carriers Electron carriers function in
photosynthesis and cellular respiration. Three major electron
carriers are listed below. You do not need to memorize these, but
may come across them in your reading. Photosynthesis NADP +
Respiration NAD + FAD These carriers work to form electron transfer
chains in many biochemical pathways. Slide 51 Stage 1: Light
Dependent Stage reading pages 72 Where: occurs within the grana of
chloroplasts (particularly the grana membrane) and the stroma of
the discs Key Materials in this Stage: Photosystems II Photon
Energy Thylakoid Disc/ Chlorophyll Excited chlorophyll electrons
Electron Carrier Proteins Stroma Water releasing H+ ions Enzyme ATP
Synthase Energy Carrier ADP + Pi Key Outcomes ATP H+ ions Oxygen
Photosystems I boost of Photon energy excited H+ electron energy
carrier NADP Key Outcomes NADPH+ Slide 52 Light to Dark Reaction
Slide 53 Photosynthesis Slide 54 Diagram of Light Dependent Stage
Slide 55 Stage 2 Light Independent (Dark) Stage reading pages 72
Where: occurs within the stroma of the chloroplasts Key Materials
in this Stage: ATP NADPH+ CO2 PGA Enzyme rubisco Produces PGAL
(Glycerheldihyde phostphate) universal building block of
carbohydrates Then PGAL can easily be converted into 6 carbon
glucose molecule C 6 H 12 O 6 Slide 56 occurs in the stroma of
chloroplasts this stage does not require light but It does not have
to take place in the dark! it involves the reduction of carbon
dioxide using NADPH and ATP from the light-dependent reaction. for
C3 plants (and photosynthetic bacteria), the carbon reductions
begin with the Calvin cycle, the carbon dioxide is fixed by
combining it with a 5-carbon compound ribulose biphospate (RuBP)
This forms an unstable 6-carbon compound Continued Stage 2: Light
Independent Stage Sometimes referred as Dark Reactions but doesnt
ohave to occur in dark reading pages 72 Slide 57 Light Independent
stage C3 plants The 6-carbon compound breaks down into two
molecules of the 3-carbon glycerate 3- phosphate (Phosphoglycerate
- PGA). Carbon-Dioxide Fixation ATP and NADPH (from the
light-dependent reaction) are used to convert PGA into
glyceraldehyde 3-phosphate (PGAL). PGAL can be converted into
glucose. Some of it is used to regenerate RuBP. ADP and NADP return
to the light-dependent stage Each time the cycle precedes, one CO 2
molecule is fixed and reduced. To produce a 6 carbon glucose
molecule, 6 turns of the cycle must take place Task See figure 3.22
& Complete Biozone 47/ 47 Slide 58 Summary of photosynthesis
reading pages 75-77 one important product formed in the calvin
cycle is PGAL (phosphoglceraldehyde), a compound that contains 3C
atoms. PGAL can react to form various sugars, including glucose,
fructose, sucrose. sucrose is the form in which carbohydrates are
transported through the phloem. Starch (a polysaccharide) is the
storage carbohydrate in plant cells. Tasks Quick Check 9 - 11 Slide
59 Calvin Cycle Carbon Fixation (light independent rxn). Carbon
Fixation (light independent rxn). C 3 plants (80% of plants on
earth). Occurs in the stroma. Uses ATP and NADPH from light rxn.
Uses CO 2. To produce glucose: it takes 6 turns and uses 18 ATP and
12 NADPH. Slide 60 Light Independent Stage Slide 61 Photosynthesis
Overview Slide 62 Light Independent stage C4 plants in a small
number of plants, a series of reactions preceeds (goes before) the
Calvin cycle these plants are known as C4 plants the first step in
C4 plants, one 3c compound is fixed to form a C4 compound Occurs in
mesophyll cells the C4 compound undergoes further reactions and is
transported to cells surrounding the vascular bundles Here the C4
plant releases a molecule of CO2 which enters the Calvin cycle Task
Biozone page 47-48 Slide 63 C4 Plants Hot, moist environments Hot,
moist environments. 15% of plants (grasses, corn, sugarcane). 15%
of plants (grasses, corn, sugarcane). Divides photosynthesis
spatially. Divides photosynthesis spatially. Light rxn - mesophyll
cells. Calvin cycle - bundle sheath cells. Slide 64 C3 and C4
plants Differ in leaf anatomy C 4 plants have a ring of
photosynthetic cells known as bundle sheath cells around vascular
bundles as well as mesophyll cells. C 3 plants have only the
mesophyll cells that are photosynthetic. The first step of carbon
fixation occurs more rapidly in C 4 plants. The first step in C 3
plants occurs in the mesophyll cells. These are close to stomata
and air spaces. C 4 plants are able to use CO 2 more efficiently
and carry out photosynthesis are a higher rate. C 4 plants occur in
the hot dry deserts where the stomata are often closed during the
day. C 3 plants are high producers in the forests and ecosystems in
temperate regions. Slide 65 Redox Reaction transferonemore
electrons one reactantanother The transfer of one or more electrons
from one reactant to another. Two types: Two types: 1.Oxidation
2.Reduction Slide 66 Oxidation Reaction losselectrons The loss of
electrons from a substance. gainoxygen Or the gain of oxygen.
glucose 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Oxidation Slide 67
Reduction and Oxidation Reminder: When a molecule gains a hydrogen
atom or electron during a reaction it is said to have been reduced.
When it loses a hydrogen atom or electron, or gains an oxygen atom,
it is said to have been oxidised. So a reduction and oxidation
reaction occur together. If one substance is oxidised the other is
reduced. When a substance goes from being reduced to oxidised,
energy is released. Eg. Fuels burning in the air. Slide 68
Photosynthesis - Overview + Energy Slide 69 Cellular Respiration
reading pages78-79 Respiration - Overview Slide 70 Cellular
Respiration reading pages78-79 The chemical energy in glucose and
other organic compounds is not directly used by cells. This energy
is transferred to other compounds, typically ATP, before it can be
used by cells. Cells carry out a series of reactions that release
chemical energy and transfer it to ATP (then immediately available
to the cell) The series of energy releasing reactions that break
organic compounds of foods (lipids, proteins & carbohydrates),
releasing chemical energy that is trapped in the form of ATP is
known as Cellular Respiration Cellular Respiration: The series of
energy releasing reactions that break organic compounds of foods
(lipids, proteins & carbohydrates), converting this to the
usable form, ATP Glucose (C 6 H 12 O 6 ) is an energy rich mcule
and can be used as an energy source. Cellular respiration may occur
in the absence of oxygen, this is called anaerobic respiration
Cellular respiration may occur in the presence of oxygen, this is
called aerobic respiration Aerobic respiration yields (much) more
ATP molecules per unit of organic material than does anaerobic
respiration Aerobic respiration gives 36 (38 in some cases) mcules
of ATP Anaerobic produces 2 mcules of ATP for each molecule of
glucose. Slide 71 EQUATION FOR RESPIRATION C 6 H 12 O 6 + GLUCOSE
6O 2 OXYGEN 6CO 2 + CARBON DIOXIDE 6H 2 O + ENERGY WATER 36 38 ATP
Slide 72 Mitochondria: Site Of Respiration In Eukaryotes Slide 73
Are membrane bound organelles suspended in the cytosol of
eukaryotic cells Are the site of some stages of aerobic respiration
(double membrane bound!): Have an outer membrane and a highly
folded inner membrane, called cristae Fluid inside called matrix
Contain respiration enzymes on the internal membranes Are the
production site of most ATP occur in larger numbers in cells with a
higher energy requirement Mitochondria See figure 3.29 page 82
Slide 74 Anaerobic Vs Aerobic reading page80 (Table 3.2)
AnaerobicAerobic Oxygen not requiredOxygen required Rapid ATP
ProductionSlow ATP Production Mammals sustain over a short period
(60 secs) Sustain indefinitely Less efficient energy transferMore
efficient energy transfer 2 mole of ATP produced per 1 mole of
glucose used 36 mole of ATP produced per 1 mole of glucose used
(some 38) Various waste products: lactic acid, water (Humans)
Ethanol, CO2 (Yeasts) Butyl alcohol (bacteria) Waste Products: CO2
and water Biozone: Page 50 Slide 75 Slide 76 Aerobic Respiration
reading page 81 Respiration Summary Reaction The three "stages" of
Respiration 1. Glycolysis - involves the initial oxidation (and
partial breakdown) of Glucose 2. Krebs Cycle - is the further
removal of the electrons from the remnants of Glucose (called
Pyruvate). 3. Electron Transport Chain - is where the energy of the
electrons from the above Redox reactions is used to make ATP. C 6 H
12 O 6 + 6O 2 6CO 2 + 6H 2 O E 36-38 ATP Slide 77 Stage 1:
Glycolysis reading page 82 glycolysis occurs in the cytosol of
cells. each step is catalysed by a specific enzyme. the aim of
glycolysis is to transform 6 carbon glucose molecules into 3 carbon
pyruvate molecules. in the process 2 ADP molecules are charged into
ATP (note energy transfer) Hydrogen atoms are removed from glucose
and collected by acceptor molecules, nicotinamide adenine
dinucleotide: 2NAD 2NADH to be used in step 3 the pyruvate
molecules move into and are used for the second stage of
respiration the krebs cycle. Slide 78 Step 1: Glycolysis Glycolysis
simplified: 6 Carbon Glucose 2 x 3 Carbon Pyruvate 2 ATP 2 ADP + Pi
2 NAD 2 NADH Slide 79 Slide 80 GLYCOLYSIS Energy will be released
from molecules as the electrons are removed and Oxygen atoms are
added. In Respiration, this occurs Carbon by Carbon until each of
the six Carbons in the Glucose has been completely oxidized to
Carbon Dioxide. The process starts with Glycolysis, which is the
splitting of the the six-carbon sugar Glucose into 2, 3-Carbon
sugars (each is called Glyceraldehyde). After this, the 3-Carbon
Glyceraldehyde is oxidized as the electrons are removed. This
eventually provides our cells with Energy in the form of ATP. The
reactions of Glycolysis The term Glycolysis mean
"Sugar-splittingATP Slide 81 definition: a cyclic series of
biochemical reactions, usually in the mitochondria, that represents
the final common pathway in all aerobic organisms for the oxidation
of amino acids, fats, and carbohydrates, and that converts the
citric acid, etc. from food into carbon dioxide and ATP Step 2:
Krebs Cycle reading page 82-83 Slide 82 occurs on the inner
membranes (cristae) of mitochndria uses the pyruvate from
glycolysis. pyruvate molecules leave the cytosol and enter the
mitochondia. hydrogen atoms are gathered by acceptor molecules,
with a total of 4 NADH and one FADH 2 for each pyruvate molecule
(note 6 Hydrogen in 6 out!) another intermediate product formed is
Acetyl Coenzyme A. for each molecule of pyruvate used 3 carbon
dioxide molecules are formed. 1 ATP also produced for each pyruvate
Slide 83 Pyruvate (3 carbon molecule is converted to a 2 carbon
molecule, Acetyle coenzyme A prior to stage 2 Krebs Cycle. Carbon
Dioxide is formed from this oxidation reaction. Slide 84 Slide 85
Step 2: Krebs Cycle Cytosol Mitochondria Pyruvate CO 2 Coenzyme A
Acetyl Coenzyme A NAD NADH CO 2 ATP ADP + P FAD FADH 2 3NAD 3NADH
Krebs Cycle Slide 86 Slide 87 Step 3: Electron Transport reading
page 83 takes place on compounds within the inner membrane of the
mitochondria (cristae) compounds called cytochromes Requires oxygen
as an input (substrate) involves reactions of loaded acceptor
molecules such as NADH and FADH2 from the previous two stages.
during ET electrons from loaded acceptors (NADH & FADH2) are
successively transferred from one cytochrome to another until the
hydrogen are finally accepted by an oxygen. when oxygen combines
with this loose hydrogen 6 water molecules are produced. In total
32 ATP produced Slide 88 Step 3: Electron Transport Water (H2O)
Oxygen NADH NAD ADP + P ATP FADH2 FAD Slide 89 Slide 90 Slide 91
RESPIRATION CYTOPLASM GLYCOLOSIS HAPPENS HERE! MITOCHONDRIA
RESPIRATION HAPPENS IN THIS ORGANELLE! PROTEINSCARBS(SUGARS)
AMINOACIDS FATS(LIPIDS) GLUCOSE C 6 H 12 O 6 ACETYL-CoA PYRUVICACID
GLYCOLOSIS IN CYTOPLASM NO OXYGEN! KREBS CYCLE AND
ANDELECTRONTANSPORT MAKES 36 ATPS MAKES 2 ATPS O 2 ENTERS HERE CO 2
IS RELEASED ATP TOTALS GLYCOLOSIS=2 Krebs + ETC =36 minus 2 Overall
=36! Slide 92 Outcome Of The Three Stages reading pages 83-84 Tasks
Examine Table 3.3 & 3.32 & 3.4 Quick Check 14 & 15
Biozone pages: 51-52 Slide 93 Anaerobic Respiration in Some Human
Tissue reading page 89-92 Glucose + 2 ADP + 2Pi 2 ATP + lactic acid
when the body undertakes strenuous short term exercise, in some
tissues (ie muscle) a process called anaerobic glycolysis occurs
does not require oxygen is a series of reactions in the cytosol
transfers some of the chemical energy in glucose to chemical energy
in ATP glucose is converted to Pyruvate which in turn is converted
into Lactate acceptor molecule (NAD) used in process of converting
pyruvate produces a net gain of two ATP molecules for each glucose
molecule produces waste called lactate Lactate is toxic and in
excess causes pain and fatigue in the tissue. Slide 94 Anaerobic
Respiration To Produce Bread and Beer anaerobic Respiration in
yeasts is called Fermentation. during fermentation, pyruvate is
broken down to carbon dioxide and ethanol (alcohol). beer is made
by fermenting barley grains. spirits are made by fermenting: Vodka
Potatoes Fruit Juice Brandy Molasses Rum Glucose + 2 ADP + 2Pi 2
ATP + ethanol + CO 2 Tasks Quick Check 16-18 Biozone 53 Slide 95
Slide 96 What Happens During Starvation? Reading page 93 animals
require a continuous supply of energy and matter for survival when
an animal is starved it uses energy from body tissue. after glucose
is used up, fats and then proteins are used. during starvation
people use up to 97% of fat tissue, 31% of skeletal muscle and 27%
of blood. when an animal reaches this stage, it is called
autophagia (feeding off self). see fig 3.42 page 93 Tasks Quick
Check 19-20 Slide 97 Students to complete Biochallenge page 96
Students to complete Chapter review Pg 97 99
