Download Cellular Respiration - Miss Jan`s Science Wikispace

Do now – make sure the following
terms are in your glossary
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Turgid
Flaccid
Facilitated diffusion
Vesicle
Endocytosis
Exocytosis
Cellular Respiration
Introduction to Respiration
SLOs
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Describe the key component/ terminology used in
respiration what each molecule does
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ATP – energy carrier (analogy with money)
NADH – carries hydrogen atoms
Glucose
Acetyl CoA
Pyruvate
Krebs Cycle
Electron transport system
Give the overall word and chemical equation for
the respiration reaction
State the reactants and products in respiration
Respiration
Respiration = conversion of chemical
energy in organic compounds into energy
that can be used by the cell.
 Large food molecules are broken down to
release energy. I.e. Glucose is broken
down via a series of enzyme reactions.
 ATP (Adenosine triphosphate) is the endproduct of cellular respiration
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Respiration Equation
Glucose + oxygen
C6H12O6 + O2
energy + carbon dioxide + water
CO2 + H2O + energy
Role-playing demo
ATP (Adenosine triphosphate)
ATP is the energy carrier in cells. It diffuses
through cells and is used for all energyconsuming processes in the cell
 ATP exists in three forms, you only need to
know two of these forms:
- ATP = high energy form, energy carrier
- ADP (adenosine diphosphate) = the “empty”
energy carrier
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ATP (continued)
ATP ↔ ADP + Phosphate + energy
OR
Adenosine-P-P-P
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Adenosine-P-P + energy + P
ATP (continued)
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ATP loses a phosphate when it gives up its
energy, and becomes ADP
ADP has to return to the cytoplasm and the
mitochondria to be recharged with energy by
the process of respiration
The conversion of ATP to ADP + Pi and the
reverse reaction is called the ATP/ADP cycle.
The ATP/ADP cycle provides cells with
energy for cellular activity.
The ATP/ADP cycle
Overall equation for
Respiration
6O2 + C6H12O6 + 38 ADP + 38 P
 enzymes
6CO2 + 6H2O + 38 ATP
ATP song (to the tune of the Beatles "Yesterday")
ATP, active transport needs you, can't you see?
Sodium pumps require energy to go against the gradient.
Cilia and flagella depend on you, not to mention pinocytosis
to internalize small molecules.
Sometimes when water needs to be pumped out of a cell,
That's when contractile vacuoles make it seem more
iso-to-o-o-nic.
ATP, the triphosphate of adenosine; ribose has five carbons
in between.
Three phosphates and an adenosine.
Glucose finds its way through the carrier molecules;
Those are proteins which are embedded in the cell
membrane.
Suddenly, turgor pressure builds up in a leaf
When water rushes into the hypertonic plant cells
Without the help of ATP.
Burning paper demo
Types of Respiration
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Aerobic respiration: respiration occur in
presence of oxygen
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Anaerobic respiration: respiration occur in
absence of oxygen
(anaerobic = “without air”)
NAD – the hydrogen carrier
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Hydrogen contains most of the energy that
charges up ADP to ATP.
The hydrogen comes from the breakdown of
glucose during respiration.
The hydrogen is carried around by the carrier
nicotinamide adenine dinucleotide (NAD)
When it is ‘full’ it is NADH2
Do Now – try to do this without
looking at your notes!
1. Give the word and symbol equations for cellular
respiration
Glucose + oxygen  energy + carbon dioxide + water
C6H12O6 + O2  CO2 + H2O + energy
2. Name the two forms of ATP – which is the high
energy form?
ATP – adenosine triphosphate (high energy form)
ADP – adenosine diphosphate (energy carrier)
3 Stages of respiration
1.
2.
3.
Glycolysis
The Krebs cycle (citric acid cycle)
The respiratory chain (electron transport
system)
[Sometimes the formation of acetyl coenzyme A
is included a separate step – see p68]
1. Glycolysis
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Glycolysis = “glucose-splitting”
Both aerobic and anaerobic respiration
begin with glycolysis
Takes place in the cytoplasm
Glucose (6C) is broken down into pyruvate
(3C) molecules and 2ATP (net gain)
2 NADH2 carry hydrogen to the electron
transport chain
The Krebs cycle
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Can only occur in the presence of O2 (aerobic
only)
The pyruvate produced from glycolysis diffuses
into the matrix of the mitochondria [matrix =
space enclosed by the inner mem.], where they
enter the Krebs cycle.
Pyruvate reacts with a molecule called
coenzyme A, and forms acetyl coenzyme A
Pyruvate acetyl coenzyme A (acetyl coA)
+ CO2
The Krebs Cycle (continued)
Acetyl group in acetyl coA is broken down to
CO2, H atoms, and ATP in the Krebs cycle.
Coenzyme A is not broken down and return to
pick up another acetyl group
i.e. Pyruvate
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Acetyl CoA
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Acetyl group  ATP + CO2 (waste) + H+
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The Krebs cycle (continued)
The Respiratory Chain
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Most of the ATP is made in this step
Takes place on the inner membrane of the
mitochondrion (cristae)
Also aerobic (needed to oxidise hydrogen to
water)
Uses the hydrogen produced in the Krebs
cycle. A chain of reaction results in the
release of ATP.
High energy electrons are produced by the
hydrogen (from Krebs cycle)
The Respiratory Chain
(continued) – Advance
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The electrons are passed along the
respiratory chain, losing their energy to H+
pumps across the cristae (folding of the inner
mito. mem.)
The H+ ions move back across the cristae
after the electron has passed along the
respiratory chain, providing energy for ATP
production.
Oxygen is used to oxidise hydrogen to water
Yield of energy:
 Glycolysis
= 2 ATP
 Krebs Cycle = 2ATP
 Electron transport = 34 ATP
 Total = 34 ATP
Summary
Brainpop
Cellular respiration
http://www.brainpop.com/science/cellularlifeand
genetics/cellularrespiration/
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321 REQ
Anaerobic respiration
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If oxygen is absent, pyruvate remain in the
cytoplasm and is broken down into:
 Lactic acid + energy in animals
 Ethyl alcohol + carbon dioxide + energy in
plants (fermentation)
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Lactic acid = poison (but can be take away when oxygen is
available)
Fermentation: only 2 ATP is produced (vs. 38 ATP in aerobic
respiration)
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Factors Affecting the rate of
respiration
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2.
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4.
Rate of respiration = how rapidly glucose is
broken down to produce energy
Rate of respiration depends on:
The amount of oxygen present in cells
The amount of glucose or fat present in the
cell
The cell or body’s demand for energy
Temperature – higher the temp., the greater
the rate of respiration