3. What are the solutions????
1) Alcoholic fermentation (fungi & Plants)
2) Lactic Fermentation (Animals)
One method involves transferring the hydrogen atoms of NADH
to certain organic molecules instead of the electron transport
chain. This process is called fermentation. Bacteria have
evolved dozens of different forms of fermentation, but
eukaryotes primarily use two methods: ethanol
fermentation and lactate (lactic acid) fermentation.
4. Alcohol fermentation
• AKA ethanol fermentation!!
In ethanol fermentation, NADH passes its hydrogen atoms to
acetaldehyde, a compound formed when a carbon dioxide molecule is
removed from pyruvate by the enzyme pyruvate decarboxylase.
This forms ethanol, the alcohol used in alcoholic beverages.
This process allows NAD+ to be recycled and glycolysis to continue.
The two ATP molecules produced satisfy the organism’s energy
needs, and the ethanol and carbon dioxide are released as waste
products. Humans have learned ways of making use of these
metabolic wastes.
Ethanol fermentation carried out by yeast (a variety of single-celled
fungi) is of great historical, economic, and cultural importance. Breads
and pastries, wine, beer, liquor, and soy sauce are all products of
fermentation.
5. Let’s get into it some more:
• Bread is leavened by mixing live yeast cells with starches (in flour) and
water.
• The yeast cells ferment the glucose from the starch and release carbon
dioxide and ethanol. Small bubbles of carbon dioxide gas cause the bread
to rise (or leaven) and the ethanol evaporates away when the bread is
baked.
• In beer making and winemaking, yeast cells ferment the sugars found in
carbohydrate-rich fruit juices, such as grape juice. The mixture bubbles as
the yeast cells release carbon dioxide gas and ethanol during
fermentation.
• In winemaking, fermentation ends when the concentration of ethanol
reaches approximately 12%. At this point, the yeast cells die as a result of
ethanol accumulation and the product is ready to be consumed as a
beverage.
Flooded plants undergo ethanol fermentation in the roots and may die if
oxygen is not returned to the roots.
***This is why it is important not to overwater houseplants.
8. Lactate Fermentation
• We’ve all experienced it!!
- Now you can impress all your friends with this knowledge and be a
know-it-all.
- Let’s begin:
9. What is it?
• Under normal conditions, animals such as humans catabolize glucose
by aerobic respiration. However, during strenuous exercise, muscle
cells respire glucose faster than oxygen can be supplied.
Under such conditions, oxidative respiration slows down and lactate
fermentation begins.
- In lactate fermentation, NADH produced in glycolysis transfers its
hydrogen atoms to pyruvate in the cytoplasm of the cell,
regenerating NAD+ and allowing glycolysis to continue.
- This results in a change of pyruvate into lactate. The accumulation
of lactate molecules in muscle tissue causes stiffness, soreness,
and fatigue. Lactate is transported through the bloodstream from
the muscles to the liver. When vigorous exercise ceases, lactate is
oxidized back to pyruvate, which then goes through the Krebs cycle
and oxidative phosphorylation.
10. Note!
• The extra oxygen required to catabolize lactate to CO2 and H2O
(through the aerobic pathway) is referred to as oxygen debt.
Panting after bouts of strenuous exercise is the body’s way of
“paying” the oxygen debt.
• Remember the question of
• “why do we breathe heavily after exercise?”
• This is why!
11.
12. Let’s watch a quick recap vid on all of this…
• https://www.youtube.com/watch?v=YbdkbCU20_M
13. Now that we have looked at the major
differences between aerobic vs anaerobic …
• Let’s compare!
• Besides the obvious: the presence or absence of oxygen during the
processes.
17. Conclusion:
• The fundamental difference between aerobic and anaerobic respiration is
the usage of oxygen in the process of cellular respiration.
• Aerobic respiration, as the name suggests, is the process of producing the
energy required by cells using oxygen. The by-product of this process
produces carbon dioxide along with ATP – the energy currency of the cells.
• Anaerobic respiration is similar to aerobic respiration, except, the process
happens without the presence of oxygen. Consequently, the by-products of
this process are lactic acid or ethanol and ATP.
• Contrary to popular belief, multicellular organisms, including humans, use
anaerobic respiration to produce energy, though this only happens when
the muscles do not get adequate oxygen due to extremely vigorous
activities
18. Aerobic vs anaerobic CR
• BOTH have glycolysis
• Total ATP –
• Aerobic= Glycolysis (2 ATP) + Krebs (2 ATP) + ETC (about 32)
Total of 36-38ish ATP
Anaerobic= Glycolysis – total of 2ATP !!!
