Cellular Respiration How Cells Harvest Chemical Energy – Cellular Respiration.
Cellular Respiration Part 1
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Transcript of Cellular Respiration Part 1
Cellular Respiration Part 1Pages 90 to 92
Fig. 9-2
Light energy
ECOSYSTEM
Photosynthesis in chloroplastsCO2 +
H2O Cellular respiration
in mitochondria
Organic molecules+ O2
ATP powers most cellular work
Heat energy
ATP
Summarize Relationship•Sunlight provides energy to power
photosynthesis – ultimate source of energy
•Photosynthesis produces glucose and oxygen needed for cellular respiration
•Cellular respiration produces water and carbon dioxide needed for photosynthesis; it also produces ATP needed to do cellular work
Do plants undergo cellular respiration?
•Yes!•They need ATP for cellular work (building,
maintaining, transporting, etc…) just like animals, protists and bacteria
Respiration - Write about it…•When you hear the word RESPIRATION,
what do you think of? Write your response on the ½ sheet provided. Write at least 2 sentences explaining what respiration means to you. You should use complete sentences in your answer.
How is your breathing related to cellular respiration?•Breathing provides the oxygen needed for
cellular respiration to occur•Breathing eliminates carbon dioxide
waste produced by cellular respiration
Complete balanced equation for cellular respiration…• C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP•Glucose + oxygen yields carbon dioxide +
water + Energy•Is this reaction endergonic or exergonic?
▫Exergonic – releasing energy
Differentiate between life sustaining activities and voluntary activities• Life sustaining
▫ Heart pumping▫ Breathing ▫ Maintain Body Temp▫ Essential for LIFE▫ 75% of your daily energy
requirements
• Voluntary▫ Biking▫ Running▫ Swimming▫ Etc..▫ 25% of your daily energy
requirements
Redox Reactions (oxidation/reduction)•The transfer of electrons during chemical
reactions releases energy stored in organic molecules
•This released energy is ultimately used to synthesize ATP
•Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactions
Redox Reactions• In oxidation, a substance loses electrons,
or is oxidized•In reduction, a substance gains
electrons, or is reduced (the amount of positive charge is reduced)
Fig. 9-UN1
becomes oxidized(loses electron)
becomes reduced(gains electron)
Cellular Respiration - Redox•What is being oxidized (gives up
electrons)▫Glucose
•What is being reduced (takes on electrons)▫Oxygen
Fig. 9-UN3
becomes oxidized
becomes reduced
What is the role of dehydrogenase in cellular respiration?•The enzyme that catalyzes the chemical
reaction in which one or more hydrogen atoms are removed from a molecule
Dehydrogenase
What is the role of NAD+ (NADH)?• NAD+ accepts electrons from carbon containing
compounds (e.g. glucose) to form NADH• NADH then shuttles the electrons to an electron
transport chain where they are used to create ATP• It is one of the electron carriers of cellular
respiration• This is a redox reaction• What is oxidized?
▫Glucose / carbon compounds• What is reduced?
▫NAD+ to form NADH
Fig. 9-4
DehydrogenaseReduction of
NAD+
Oxidation of NADH
2 e– + 2 H+ 2 e– +
H+
NAD+
+ 2[H]
NADH
+
H+
H+
Nicotinamide(oxidized form)
Nicotinamide(reduced form)
Fig. 9-5
Free
ene
rgy,
G Fr
ee e
nerg
y,
G
(a) Uncontrolled reaction
H2O
H2 + 1/2 O2
Explosiverelease ofheat and
lightenergy
(b) Cellular respiration
Controlled
release ofenergy forsynthesis
ofATP
2 H+ + 2 e–
2 H + 1/2 O2
(from food via NADH)
ATP
ATPATP
1/2 O2
2 H+
2 e–Electron
transportchain
H2O
Where is the Electron Transport Chain?•The inner membrane of the mitochondria
(aka – the cristea)