Download Cellular-Respiration Student

Cellular Respiration
Nelson Biology
Chapter 7
Pages 204 - 228
General Learning Outcome
• Explain the role of cellular respiration in
releasing potential energy from organic
compounds
Focusing Questions
• How is the energy in organic matter
released for use by living systems?
• How do humans in their application of
technologies impact photosynthesis
and cellular respirations
7.1 The Importance of Cellular
respiration
Pg. 204-209
Importance of Cellular Respiration
• Cellular respiration is the process
where
Importance of Cellular Respiration
• When cells require energy it is
supplied by ________
– This is the role of _____________________
• Both plant and animal cells release
energy
– Energy is stored in bonds of ___________
Electron Carriers
• NADH
– __________ electrons in cellular processes
• NAD+
– __________ electrons in cellular processes
• FADH2
– __________ electrons in cellular processes
• FAD+
– __________ electrons in cellular processes
L.E.O. goes G.E.R.
• Loss Electrons
Oxidation
• Gain Electrons
Reduction
• The transfer of electrons _________
__________
• This energy can be used to make _____
Oxidation and Phosphorylation
ATP
High Reactants - glucose
Energy
Oxidationreduction
reaction
Energy from the
Energy is
reaction
Released
Low
Energy
Products CO2+ H2O
ATP Formation
ADP + P
Energy, Cells & ATP
• Energy for most cellular processes are
supplied by:
ATP
• Typical human cell estimated to contain
1.0x109 molecules ATP
– Continually broken down to __________
– __________ energy to __________
– __________ to be used again
Active Transport
• Used to ____________________into or
out of the cell
• Is __________ a concentration gradient
– Often referred to as “__________”
• Utilizes _________________________________
and energy from __________
Sodium-Potassium Pump
Large Scale Motion
• Critical use of ATP
– Energy from ATP
used for
____________________
Glucose & ATP
• All cells use energy from __________
• ATP ____________________in food
– Provide relatively ____________________of
__________ per molecule
Carbohydrates - They are Good!
• Most useable source of energy
– Notably in the form of __________
• Contains about __________ as much energy as
an individual ATP molecule
• ____________________ by the cell
• Some energy in glucose is __________________
ATP is like GOLD
• The cell is like a
Western
amusement park
– Operates off gold
coins
– Stores only accept
gold coins
Bars vs. Coins
• Glucose is like bars of gold
– Contains 100x more energy
than an individual ATP coin
– Have ____________________
____________________
• Virtually all process
conducted require__________
– ____________________________
______________________
Breaking the Bonds, Releasing the
Energy
• Respiration - _________________of food
molecules are ____________________
– New bonds form in resulting
____________________
• _____________________________to break
chemical bonds
• Energy is ____________________when
new bonds form
• ______________________________than
consumed
Starting
Substance
Exchange Rate
• Food molecules such as glucose have
____________________
– Trade in one $100 gold bar for individual
coins
• Exchange rate is at best 36%
• For every 1 gold bar, will only receive $36 in
gold coins
– ____________________
2 Types of Cellular Respiration
• Aerobic Cellular Respiration
– Takes place in __________________________
– Complete ____________________
• End products: ____________________molecules
• Anaerobic Cellular Respiration
– Takes place in ____________________
– Glucose __________ completely oxidized
• Broken into ____________________
Aerobic Respiration
•
•
•
•
Stage
Stage
Stage
Stage
1:
2:
3:
4:
____________________
____________________
____________________
____________________
______________________________________________________
Anaerobic Cellular Respiration
• Stage 1: __________
• Stage 2: __________
7.2 Glycolysis
Pg. 210-212
Glycolysis
• Greek for
“____________________”
• Glucose molecule
(________________) breaks
down to two______
molecules (
carbon
sugar)
• Takes place ____________
____________________
• Occurs in the __________
of the cell
• Pyruvate (pyruvic acid)
moves into the
________________________
________________________
• Uses a hydrogen
carrier __________
– Photosynthesis uses
NADPH
• Produces a net of
__________
molecules
– Also produces
____________________
Key Steps in Glycolysis
1. __________molecules are __________ ______________________________
2. Redox reactions occur - 2 positive
__________remove _____ from the
pathway to form ____________________
3. Enough energy is released to join ___
_____ molecules with ______molecules
 this forms _________molecules
Glycolysis
• When complete, cell has
• consumed
– ______________________
– produced
– __________molecules______
________________________
____________________
– These ATP molecules are
available for __________
__________ __________
(the gold coins)
REACTANTS
PRODUCTS
Glycolysis
• Alone glycolysis is not a highly-efficient energyharnessing mechanism
– Transfers only _________________________in glucose to
ATP
• Some energy released as ____________________
• Majority is trapped in __________________________________
• ALL organisms carry out __________ - either as only
ATP source or as first step in more energy-productive
process
– EX. ______________________________
7.3 Aerobic Cellular Respiration
Page. 213-220
RECALL: Aerobic Respiration
• Stage 1: glycolysis
– 10 step process in cytoplasm
• Stage 2: pyruvate oxidation
– 1 step process in mitochondria
• Stage 3: the Krebs cycle
– 8 step cyclical process in mitochondria
• Stage 4: ETC and chemiosmosis
– Multi-step process in inner mitchondrial
membrane
C6H12O6 + 6O2 +36ADP +36Pi  6CO2 + 6H2O + 36
ATP
Mitochondria
- Round or
sausage-shaped
organelles in cell’s
cytoplasm
___________________
___________________
___________________
- Cannot proceed
without free oxygen
Mitochondrial Powerhouse
• Cristae
– Folds in inner
membrane
– Increases ________
area
– Site of ATP
synthesis
• Mitochondrial
Matrix
– Site of the Citric
Acid Cycle
Stage 2: Pyruvate Oxidation
• By the end of Stage 1  cell has
formed
• 2 ATPs,
• 2 NADHs,
• 2 pyruvate molecules
Stage 2: Pyruvate Oxidation
• Pyruvate oxidation is a chemical
pathway connecting glycolysis in
cytoplasm with the Kreb’s cycle in
the mitochondrial matrix
– The 2 pyruvate molecules must be
transported through the two
mitochondrial membranes into the
matrix
Key Steps in Pyruvate Oxidation
1.
2.
One CO2 is removed from each pyruvate released as a waste product
Remaining 2-carbon portions are oxidized by
NAD+
1.
Gains 2 H+ (2 protons and 2 electrons) from pyruvate
1.
Remaining 2-C compounds become an acetic acid group
1. High energy hydrogens are transferred to NAD+
3.
Coenzyme A (CoA) attaches to acetic acid group forms acetyl-CoA
1.
This acetyl-CoA can enter the Krebs cycle
Stage 3: the Krebs Cycle
Key Features of the Krebs Cycle
1. Krebs cycle occurs ______ for each
molecule of ________ processed
2. Acetyl-CoA enters and releases the CoA,
which is recycled for the next pyruvate
3. During one cycle
1.
___ NAD+s and __ FAD are reduced  forms
____ NADH and ___ FADH2
2. 1 ADP + Pi combine to form 1 ___
3. 2 CO2 molecules are produced and released as
________
Key Features of the Krebs Cycle
• ALL 6 carbon atoms of glucose have
been ________ to CO2
– Released from cell as metabolic waste
• All that remains is some free energy in form of
ATP and high-energy NADH and FADH2
• NADH and FADH2 go on to Stage 4
– Here much of their energy will be
transferred to ATP
Stage 4: Electron Transport and
Chemiosmosis
Stage 4
• Occurs on the _______ mitochondrial
membranes
• NADH and FADH2 eventually transfer
the hydrogen atom electrons through
the electron transport chain
– The energy associated with the electrons
pumps H+ ions into the intermembrane
space
Oxygen - the Final Acceptor
• Oxygen _______ the 2 e- from the final
carrier
– Also uses 2 H+ ions from the matrix
• Forms water H2O
• This is why all aerobic organisms must obtain
oxygen from the environment on a continual
basis
Chemiosmosis & Oxidative ATP
Synthesis
• Production of ATP in mitochondria is
similar to that which occurs in the
____________ membranes in
photosynthesis
•In photosynthesis, the use of light
energy in ATP synthesis is called
photosphosphorylation
• In cellular respiration, it is referred
to as oxidative phosphorylation, or
oxidative ATP synthesis
• Named because the energy used
to drive ATP synthesis comes from
the energy released in the ETC from a series of oxidation
reactions
Where does the ATP go?
• After ATP molecules are formed by
chemiosmosis they are transported
through both mitochondrial
membranes
– Used to drive processes requiring energy
All in the Family
• The three stages of aerobic cellular
respiration - pyruvate oxidation, the
Krebs cycle, and ETC &
chemiosmosis) are all linked to each
other
– Dependent on _________ for the
production of ________
7.4 Anaerobic cellular respiration
Page 221-228
Anaerobic Cellular Respiration
• Glycolysis changes _____ to NADH
– Without NAD+ this reaction does not
occur
• Cells have a ________ supply of NAD+
• Without a way to convert NADH to NAD+,
glycolysis will cease
– ATP no longer will be produced and cell death
occurs
Anaerobic Cellular Respiration
• Evolved in organisms as a way of recycling
NAD+
– Allows glycolysis to continue
• One method involves transferring H atoms
of NADH to specific organic molecules
– Process called fermentation
•
•
Anaerobic Cellular Respiration
• Occur in only 2 stages
– Glycolysis: same process as that in
aerobic cellular respiration
– Fermentation: products of glycolysis
recycled in 2 different ways
• ___________ and _________ are final waste
products (alcohol fermentation)
• Lactic acid is the final waste product (lactic
acid fermentation)
Alcohol Fermentation
• NADH molecules pass their H atoms
to acetaldehyde
– This forms ___________
• Same type of alcohol used in alcoholic
beverages
– Recycles NAD+ and allows glycolysis to
continue
• The 2 ATP produced are enough to satisfy the
organism’s energy needs
Alcohol Fermentation - Application
• Can be carried out by a single-celled fungi
C6H12O6 + 2 ADP + 2 Pi  2C3H6OH + 2CO2 + 2 ATP
ethanol
Lactic Acid Fermentation
• Under normal conditions, humans
obtain energy from glucose by
aerobic cellular respiration
– During strenuous exercise, the ATP
demand is greater than what can be
supplied by aerobic respiration alone
Lactic Acid Fermentation
• NADH transfers its H to pyruvate in
the cytoplasm
–
– Pyruvate changes into lactic acid
Exercise Phsiology
• Most common problem faced by
athletes  shortage of energy
– Aerobic fitness  factor in judging overall
fitness
Exercise Phsiology
• Muscle cells require energy from ATP
• ATP production requires oxygen
• Thus assume ATP production
increases if more oxygen is absorbed
by body cells
Maximum Oxygen Consumption
• VO2 max
– Measure of the body’s ability to generate
energy required for activity