Respiration Flashcards
Aerobic respiration
the release of energy (from organic compounds) which uses (needs) oxygen
anabolic or catabolic and why?
catabolic because a complex molecule is broken down into simpler molecules with the release of large amounts of energy
equation for the aerobic respiration
C6H12O6 + 6 O2 = 6 CO2 + 6 H2O
STAGE 1
glycolysis
anaerobic no oxygen
occurs in cell cytosol
glucose (6C) splits in half
forms pyruvic acid (3C)
oxygen presents- Stage 2 reactions proceed in the mitochondrion.
Oxygen absent ~ Fermentation or ‘anaerobic respiration’ occurs and stage 2 reactions do not take place.
STAGE 2
Krebs’s cycle
aerobic
lumen of mitochondria
pyruvic acid losses CO2
forms acetyl co enzyme A
joins Krebs cycle
products:
1. ATP - breaks down with the release of energy
2. carbon dioxide - released into atmosphere
3. NADH - formed when 2 energized electrons and a hydrogen ion is captured by NAD+
STAGE 2
Electron Transport Chain
oxygen must be present
cristae of the mitochondria
NADH moves to the cristae
here it releases pair of energized electrons
passed down by protein carriers
energy is lost picked up by ADP to form ATP
at the end water is formed
now low energized electron pair transfer to oxygen combine with hydrogen to form water
final electron acceptor oxygen
products are = water and ATP
fermentation
defn : anaerobic respiration of glucose.
Fermentation involves Glycolysis only in the cytosol
Occurs in muscles deprived of 02, yeast and some bacteria.
PLANTS
ethanol and glucose
C6H12O6 = 2 C2H5OH + 2 CO2 + 2ATP
ANIMALS
Glucose = Lactic Acid + 2ATP
ATP / ADP
ATP is Adenosine Triphosphate and ADP is Adenosine Diphosphate
ATP stores and transports and releases energy within the cell
The energy is stored when ADP joins with P
ADP + P + energy = ATP
The energy is released when ATP breaks down to ADP + P
ATP = ADP + P + energy
Yeast
unicellular fungus
can respire both aerobically or anaerobically but mainly anaerobically
yeast life cycle
Yeast reproduces by a form of mitosis known as ‘budding’ where the cells eventually break apart
Yeast gets it energy from anaerobic respiration (fermentation) of glucose C6H12O6 = 2 C2H5OH + 2 CO2
Glucose = ethanol + Carbon dioxide
structure
diagram of yeast budding
mitochondria
diagram
- non nuclear DNA
- outer membrane
- inner folded membrane
- cristae
- lumen
- ribosomes
Role of Microorganisms in Industrial Fermentation
- Bacteria and fungi are used.
- Conditions of temperature, pH and nutrient levels monitored and controlled carefully.
- Products include antibiotics, vitamins, alcohol, cheese and yoghurt,
- These products are made in bioreactors.
Prepare and Show the Production of Alcohol by Yeast.
sterilize equipment to kill all living organism
obtain two conical flask ( test and control )
prepare glucose solution
pour 300cm3 of glucose solution into conical flask
boil 5 minutes remove 02 anaerobic conditions
once cool add sachet of dried yeast ( glucose is substrate for yeast to ferment)
cover with oil layer to stop O2 from re entering
glass tubing to connect the flask to a beaker containing limewater—-limewater is the *reagent to test for carbon dioxide.
Place the conical flask in a water bath at 300C for 24 hours—300C is the *optimum temperature for yeast fermentation.
After 24 hours , continue to monitor the apparatus until fermentation *has stopped —i.e. no more bubbles are visible.
control
add glucose only, no yeast in *the same set-up. A control is used *for comparison, *to provide a standard against which the actual experiment can be judged.
