Transcript L22 HH Cellular Respiration & ATP

Definition
......
occurs in ...
2 types ......
Equation?
Reactants  Products
Equation?
Reactants  Products
Extra Bonus Marks – Interestingly .....
• Define cellular respiration
• Identify the energy source in cells and within
a molecule of ATP
• Understand the link of ATP between
catabolic and anabolic reactions
• Explain the process of phosphrylation
• Potential for LO3
Cellular Respiration
Definition – Biochemical process by which energyrich substrate molecules (foodstuff) are
progressively broken down in enzymatic pathways
to form adenosine triphosphate (ATP, high energy
compound)
Foodstuff is usually glucose. Glucose is broken
down in a series of enzyme controlled steps.
Hydrogen and high energy electrons are removed
by dehydrogenase enzymes and used to yield ATP.
What is ATP?
Adenosine Triphosphate is a molecule
composed of:
Guess what it
would be called
• 1 x Adenosine (adenosine)
with only 2
• 3 x inorganic phosphate (Pi)
phosphates? 1
phosphate?
Adenosine
Bonds contain energy
Pi
Pi
Pi
3 Inorganic Phosphate Groups
How could it release energy?
Energy Release & ADP
When
the terminal bond is broken energy is released.
Adenosine Triphosphate
Diphosphate
A
Pi
Pi
1 Free
Inorganic
Phosphate
Molecule
Pi
2 (di-) Inorganic
Adenosine Molecule Phosphate
Energy released
molecules molecules
Inorganic Phosphate
when bond breaks
1 phosphate – adenosine monophosphate
Adenosine triphosphate (ATP)
• Main energy carrier molecule in the body (and all
living things).
• ATP is used to transfer (links) the energy released
(catabolic) from cellular respiration to synthetic
pathways (anabolic) and other cellular processes
where energy is required Which cells/processes need energy?
Carbon dioxide
and water
ATP
energy
CELLULAR
RESPIRATION
Glucose and
oxygen
Amino acids
energy
ENERGY
TRANSFER
SYNTHETIC
PATHWAY
energy
energy
ADP +Pi
Protein
Uses of ATP in cells are:
Muscle cell
Liver
cell
Image source: http://www.sccollege.edu
Image source: http://www.agen.ufl.edu
Sperm
cell
Image source: http://www.dkimages.com
Nerve cell
Image source: http://www.dkimages.com
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Muscle contraction
Driving chemical reactions
Active transport
Synthesis of e.g. protein
Transmission of nerve
impulses
Bioluminescence Demonstration Luminescence is emission of light by a
substance not resulting from heat; it is thus
a form of cold body radiation
ADD ATP
George McGavin
Edith Widder
Fluoro Fish
http://lem.ch.unito.it/didattica/infochimica/2008_GFP/Fish.html
Fluoro Fish
Taiwan's leading fluorescent fish industry has developed fluorescent
fish that only glow from their blood vessels, takes so much ATP unable
to have enough energy to reproduce.
This technology could be used in the future to detect tumours in other
species.
The Fluoro Fish are available at pet stores in all the US states, except
California. They are marketed as GloFish and are available in Star-fire
Red, Sunburst Orange, and Electric Green. They cost between $5-10.
The fluorescent zebra fish are created by microinjecting a fluorescent
gene construct into fertilized zebra fish embryos.
Australia, Canada, New Zealand and Europe prohibit
the sale of genetically modified organisms, such as
GloFish and they can not be purchased there.
Is it morally right to produce glowing fish for fish tanks?
Predict what would happen after 10 minutes? Why?
Demonstrate Questions
1. Calculate the percentage decrease
2. Why is it necessary to use percentage
decrease in length in the comparison of the
results?
3. What would be a good control for the
experiment?
4. Muscle cells use energy for contraction.
State one other cell activity that uses
energy.
ATP
• 2 million molecules of ATP per second is
needed to satisfy energy requirements for an
active cell (such as liver/muscle etc)!
• How and where is it stored?
Glucose (6C)
ATP
ATP
• Not stored! Rapid turnover of ATP molecules
occurs continuously in a cell.
• Remains quite constant as the same amount is
made that is used up (~50g)
• Cell conserves resources by only producing ATP
when needed – it is another example of feedback
inhibition .
• ATP and citric acid inhibit phosphofructikinase
Phosphorylation at step 1
Other metabolic pathways
(eg. stored as glycogen)
ADP+ Pi
Intermediate 1
Intermediate 2
Irreversible step
ATP
ADP+ Pi
ATP & citric acid inhibit
phosphofructikinase! So
go back to intermediate 2
Phosphorylation at step 3 catalysed by
phosphofructokinase
Intermediate 3
Citric Acid Cycle & Electron
Transport Chain
Phosphorylation
• Phosphorylation is process which is enzyme
controlled where a phosphate group (Pi) is added
to a molecule.
ATP
Breakdown
energy released
Build-up
energy required
ADP +Pi
Phosphorylation
• Not only making ATP is called phophorylation
(remember post translational modifiction of
proteins), also when Pi from ATP given to
another molecule in a metabolic pathway it
makes them more reactive. For example
glucose in glycolysis ......
ATP
Glucose
ADP +Pi
Glucose-6-phosphate
(high energy)
• The phosphorylation of molecules to alter
their reactivity.
Effect of phosphorylase on
phosphorylated substrate
• Investigation p100
• Controls?
• 3 minute intervals or 10 as shown below
Advantages of ATP
 Instant source of energy in the cell
 Releases energy in small amounts as needed
 It is mobile and transports chemical energy to
where it is needed IN the cell
 Universal energy carrier and can be used in
many different chemical reactions
Complete your exit slip before you go
ATP Exit cards
Draw/label ATP
Complete the following equation:
ATP  _____ + ________ + _______
The process name of adding a phosphate?
What happens to the molecules then?
Name 3 process that need ATP;
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