Download Cellular Respiration

Cellular Respiration
chapter 7
ENERGETICS ch 6&7
the Big Picture
4/28/2017
A. Autotrophs ex. Plants
make Glucose
from CO2, H2O and Light
in their chloroplasts.
B. Autotrophs & Heterotrophs
make ATP
From C6H12O6 & O2
in their mitochondria.
2
Q: Animals are heterotrophs… what do they
need to live?
A: Food, Oxygen, Water
Q: WHY???
A: To make ATP so their cells can do cellular
work.
Ex. powering: active transport, cell division, protein synthesis.
Q: How is food turned to ATP?
A: The biochemical pathway of aerobic
respiration OXIDIZES food, removing
electrons and H+, which are used to create
ATP by chemiosmosis.
ATP
Chemical work
Mechanical work
Transport work
Membrane
protein
P
Motor
protein
Solute
P
Reactants
P
P
P
Product
Molecule formed
4/28/2017
P
Protein moved
ADP  P
Solute transported
4
CELLULAR RESPIRATION IS…
The complex biochemical pathway…
–
–
Series of linked chemical reactions in which
the product of the first reaction is a reactant in
the next
By which cells make ATP by breaking down
organic compounds.
1. Carbohydrates (easiest)
2. Proteins
3. Lipids
Enzymes are used at each
step in the process…
• What do you remember about enzymes?
ENZYMES
• Protein (polypeptide made of amino acids)
catalysts of reactions that aid in all steps of
metabolism.
• Shape of “active site” is specific for a
certain substrate- so there is a different
enzyme used in each rxn.
• Lower the amount of activation energy
needed to start a rxn- so they speed up
reactions.
• Are reused.
• Examples from this unit: Coenzyme A ,
water splitting enzyme, ATP synthase,
Rubisco,.
• Enzymes assist in every step of the
biochemical pathways of photosynthesis
and cellular respiration.
ACTIVATION
ENERGY
Amount of energy
needed to start
a chemical
reaction.
HERE’S A REACTION WITH A HELPER… A CAT
ENZYMES are biological catalyst.
4/28/2017
10
SOME RELEASE ENERGY
ex. cellular respiration
SOME REQUIRE ENERGY
ex. .Photosynthesis
C6H12O6 + 6 O2  6 CO2 + 6 H2O + 38 ATP
OXIDATION is losing electrons (and protons)
C6H12O6 6 CO2 + 12 H+ + 12 eGlucose is oxidized
REDUCTION is gaining electrons (and protons)
6 O2  6 H2O
Oxygen is reduced
The electrons are picked up by “electron carrier
molecules” and transported to the Electron
Transport Chain of proteins where they do work.
Energy Molecules: ATP & NADH
A molecule that gains a phosphate
group is PHOSPHORYLATED.
e- e- H+
ATP
NADH
NAD+
ADP
A molecule that gains electrons is REDUCED.
A molecule that loses electrons is OXIDIZED.
Energy Molecules
cellular respiration’s
breakdown of glucose begins
with the biochemical pathway
of GLYCOLYSIS
•
•
•
•
•
means“to cut a sugar”
CREATES:
2 ATP
2 NADH
2 pyruvic acid
GLYCOLYSIS
TWO PHASES:
1. Energy investment
requires 2 ATP
2. Energy payoff:
creates 2 NADH
creates 4 ATP
Note: only the carbon
Skeleton is shown. There
Are oxygens & hydrogens
also
PRODUCTS:
1) 2 NADH
2) 2 ATP (net gain)
3) 2 pyruvic acid
What happens after glycolysis is
determined by the presence or
absence of oxygen…
(without oxygen)
Anaerobic Respiration
FERMENTATION
1. lactic acid
NAD+
2. Ethyl alcohol
carbon Dioxide
NAD+
(with oxygen)
Aerobic Respiration
OXIDATIVE RESPIRATION
1. 6 CO2
2. 8 NADH
3. 2 FADH2
4. up to 36 ATP
5. 6 H20 molecules
Glycolysis
& Fermentation
Q: If fermentation doesn’t
produce any more ATP
then why bother with it???
A: fermentation restores
NADH to NAD+, NAD+ is
essential for glycolysis.
If oxygen is present… reactions occur in the
MITOCHONDRIA
1.
2.
3.
4.
5.
6.
7.
Oxidation of Pyruvate
Reduction of NAD+ & FAD
Electron Transport Chain
Proton Pumping
Concentration Gradient
Chemiosmosis
ATP synthesis
Pyruvic acid conversion to
Acetate & The Krebs Cycle
• pyruvic acid diffuses into the
matrix & is oxidized
• NAD+ is reduced NADH.
• A molecule of CO2 is given off
• The remaining 2 carbon
fragment (acetate)joins with
co-enzyme A
1. Acetyl-CoA enters the Krebs
cycle and joins with a 4 carbon
compound (OAA)
2. 2 more CO2 are released and the
energy is transferred into:
3 NADH, 1FADH2, 1ATP
3. OAA is regenerated
4. Process repeats
Pyruvic acid conversion to
Acetate & The Krebs Cycle
• pyruvic acid diffuses into the
matrix & is oxidized
• NAD+ is reduced NADH.
• A molecule of CO2 is given off
• The remaining 2 carbon
fragment (acetate)joins with
co-enzyme A
1. Acetyl-CoA enters the Krebs
cycle and joins with a 4 carbon
compound (OAA)
2. 2 more CO2 are released and
the energy is transferred into:
3 NADH, 1FADH2, 1ATP
3. OAA is regenerated
4. Process repeats
Electron Transport Chain
• NADH and FADH2 supply
electrons to the ETC.
• Series of proteins that
electrons travel through.
• Oxygen is the final electron
acceptor at the end of the
ETC- water is formed.
• Some energy is used to
pump H+ into the Inter
Membrane Space.
• CHEMIOSMOSIS
• Kinetic Energy of H+
diffusing through ATP
synthase channels is used
to produce 34 ATP.
• (2 + 2 + 34 = 38)
Electron Transport Chain
• NADH and FADH2 supply
electrons to the ETC.
• Series of proteins that electrons
travel through.
• Oxygen is the final electron
acceptor at the end of the ETCwater is formed.
• Some energy is used to pump
H+ into the Inter Membrane
Space.
• CHEMIOSMOSIS
• Kinetic Energy of H+ diffusing
through ATP synthase channels
is used to produce 34 ATP.
• (2 + 2 + 34 = 38)
VOCAB SCRAMBLE
ATP
NADH
FADH2
NADPH
ATP synthase ADP
PSII
PS1
Water
oxygen
pigments
chloroplast
Mitochondria
Coenzyme A
CO2 Calvin Cycle
Krebs Cycle
chemiosmosis RUBP
PGAL
Glycolysis
ETC
Rubisco
protonpump
Photons
NAD+
FAD
NADP+
Chlorophyll A
Chlorophyll B
carotenoids PGA
Make a VENN DIAGRAM showing these words’association
PHOTOSYNTHESIS
BOTH
RESPIRATION
VOCAB SCRAMBLE
PHOTOSYNTHESIS
BOTH
• used
WATER
• formed
OXYGEN
• formed
GLUCOSE
• Rubisco
ENZYME
• chloroplast
ORGANELLE
Pigments:
Chlorophyll A&B, Carotenoids
• Photons-Photosystems 1 &2
• Endergonic
RXN
• NADP+/NADPH
• Calvin
• RuBP
•
•
electron carriers
RESPIRATION
formed
Used
used
Co-A
mitochondrion
glycolysis
Exergonic
NAD+/NADHFAD/FADH2
CYCLE
ATP/ADP ATP synthase
ETC/proton pump/chemiosmosis
Krebs
OAA