Download Cellular Respiration

Cellular Respiration
1. Harvesting Chemical Energy
a. Plants and animals both use products of
photosynthesis (glucose) for metabolic fuel
b. Heterotrophs: must take in energy from
outside sources, cannot make their own e.g.
animals
c. When we take in glucose (or other carbs),
proteins, and fats-these foods don’t come
to us the way our cells can use them
2. Cellular Respiration
a. Cellular Respiration is the process
that releases energy by breaking
down food molecules in the
presence of oxygen.
b. These reactions proceed the same
way in plants and animals.
c. 6O2 + C6H12O6  6CO2 + 6H2O +
ATP Energy
d. Oxygen + Glucose  Carbon
Dioxide + Water + Energy
3. Cellular Respiration Overview
a. Breakdown of glucose begins in the
cytoplasm: the liquid matrix inside
the cell
b. At this point life diverges into two
forms and two pathways
i. Anaerobic cellular respiration (aka
fermentation)
ii. Aerobic cellular respiration
Section 9-1
Chemical Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without
oxygen)
Electron
transport
Alcohol or
lactic acid
4. Glycolysis
a. Series of reactions which break the 6carbon glucose molecule down into two
3-carbon molecules called pyruvate
b. Process is an ancient one-all organisms
from simple bacteria to humans
perform it the same way
c. Yields 2 ATP molecules for every one
glucose molecule broken down
d. Yields 2 NADH per glucose molecule
Section 9-1
Glucose
Glycolysis
2 Pyruvic acid
To the
electron
transport
chain
5. Fermentation
a. Releases energy from glucose without the
presence of oxygen.
b. There are two types of fermentation:
alcoholic and lactic acid.
i.
Alcoholic fermentation is done by yeasts and
some microorganisms. It produces alcohol &
Carbon Dioxide
ii. Lactic Acid is produced by muscles during
rapid exercise when the body cannot supply
enough oxygen.
6. Anaerobic Cellular Respiration
a. Some organisms thrive in environments with
little or no oxygen
i.
Marshes, bogs, gut of animals, sewage treatment
ponds
b. No oxygen used= ‘an’aerobic
c. Results in no more ATP, final steps in these
pathways serve ONLY to regenerate NAD+ so it
can return to pick up more electrons and
hydrogen in glycolysis.
i.
End products such as ethanol and CO2 (single cell fungi
(yeast) in beer/bread) or lactic acid (muscle cells)
Section 9-1
Lactic Acid Fermentation
Glucose
Pyruvic acid
Lactic acid
7. Aerobic Cellular Respiration
a. Oxygen required=aerobic
b. 2 more sets of reactions which occur
in a specialized structure within the
cell called the mitochondria
i. Kreb’s Cycle
ii. Electron Transport Chain
Cellular Respiration: An
Overview
Section 9-1
Mitochondrion
Electrons carried in NADH
Pyruvic
acid
Glucose
Glycolysis
Krebs
Cycle
Electrons
carried in
NADH and
FADH2
Electron
Transport
Chain
Mitochondrion
Cytoplasm
8. The Krebs Cycle
a. During the Krebs Cycle, pyruvic acid
is broken down into carbon dioxide
in a series of energy-extracting
reactions.
b. Citric Acid is created in this cycle
thus giving it the nickname Citric
Acid cycle.
c. Net ATP Production is 2 ATP.
8. Kreb’s Cycle
c. Completes the breakdown of glucose
i.
Takes the pyruvate (3-carbons) and breaks it
down, the carbon and oxygen atoms end up
in CO2 and H2O
ii. Hydrogen and electrons are stripped and
loaded onto NAD+ and FAD to produce NADH
and FADH2
d. Production of only 2 more ATP but loads
up the coenzymes with H+ and electrons
which move to the 3rd stage
9. Electron Transport Chain
a. The electron transport chain uses
the high-energy electrons from the
Krebs Cycle to convert ADP to ATP.
b. Total ATP 32.
9. Electron Transport Chain
c. Electron carriers loaded with electrons
and protons from the Kreb’s cycle move
to this chain-like a series of steps
(staircase).
d. As electrons drop down stairs, energy
released to form a total of 32 ATP
e. Oxygen waits at bottom of staircase,
picks up electrons and protons and in
doing so becomes water
Section 9-2
Electron Transport Chain
Electron Transport
Hydrogen Ion
Movement
Channel
Intermembrane
Space
ATP synthase
Inner
Membrane
Matrix
Mitochondrion
ATP
Production
10. Energy Tally
a. 36 ATP for aerobic vs. 2 ATP for
anaerobic
i. Glycolysis
2 ATP
ii. Kreb’s
2 ATP
iii. Electron Transport 32 ATP
i.
36 ATP
b. Anaerobic organisms can’t be too
energetic but are important for
global recycling of carbon
Aerobic Cellular Respiration
Section 9-2
Glucose
(C6H1206)
+
Oxygen
(02)
Glycolysis
Krebs
Cycle or
Citric Acid
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
11. Energy & Exercise
a. Quick energy – Lactic Acid
fermentation is used to get quick
energy and gives off lactic acid as a
by product, thus the muscle pain.
b. Long-Term Energy – Use cellular
respiration to produce energy.
Exercising or activities that last for
at least 15 to 20 minutes. Best form
for weight control.
12. Comparing Photosynthesis &
Respiration
Photosynthesis
Cellular
Respiration
Function
Energy Storage
Location
Chloroplasts
Energy
Release
Mitochondria
Reactants
CO2 and H2O
Products
C6H12O6 and O2
C6H12O6 and
O2
CO2 and H2O
Equation
6CO2 + 6H2O 
C6H12O6 + 6O2
C6H12O6 + 6O2
6CO2 + 6H2O