Transcript cellular respiration

Cellular
Respiration:
• Overall Equation: (reverse of photo)
Glucose + Oxygen  Water + CO2 + ATP
•Takes place in the mitochondria.
•The process by which glucose in our
food is “burned” to release usable energy
in the form of ATP molecules.
2 Types
 Anaerobic – requires no oxygen (occurs in some
bacteria and yeast)
 Aerobic – does require oxygen (occurs in us and most
other organisms); much more energy efficient
Stage 1:
 (a).GLYCOLYSIS (“splitting of sugar”)
 Occurs in the cytoplasm and does NOT require oxygen
 (b).Glucose is split into (c) 2 pyruvic acids (3-carbon
sugars)
 (d)NAD+ picks up electrons to become (e)NADH
 It takes (f) 2 ATP’s to start this and (g) 4 ATP’s are
produced, giving a net gain of 2 ATP’s during
glycolysis!
Now, if NO oxygen is avail…
 (h)Anaerobic Respiration occurs…known as
(i)Fermentation!
 Pyruvic acid is converted to either:
A. (j)ethyl alcohol & CO2 (yeast for ex.) – important
in industry for breads/alcoholic beverages
OR
B. (k)lactic acid – (human muscle cells) – causes
cramping when you run out of O2
If oxygen is avail….
 (L)AEROBIC respiration occurs inside the
(m)MITOCHONDRIA!!
 Much more energy efficient than fermentation.
 Pyruvic acid will be converted through 2 more steps
after glycolysis!
 Changed into Acetyl-CoA before entering the
mitochondria
Stage 2:
 (n)Kreb’s Cycle or Citric Acid Cycle – (much like the
Calvin cycle of photosynthesis instead of building
glucose, we are breaking it down!)
 2 molecules of (o)CO2 are produced with every turn
and (p)ADP is turned into (q)ATP and energized
electrons are produced that are picked up by NAD &
FAD to be carried on to stage 3….
Stage 3:
 (r)Electron Transport Chain: much like the one in
photosynthesis, electrons are passed along like a hot
potato or a football down the field, releasing energy at
each step….(s)32 ATP molecules are formed during
this step alone!!!!
 Oxygen is necessary because it waits at “the end of the
field” for the electrons (“football”) to be passed to it
and forms the (t)water that is produced during
respiration!
 http://www.pearsonsuccessnet.com
Summary

Total ATP’s formed:
Anaerobic
vs.
Aerobic
2
during glycolysis
2
n/a
Kreb’s Cycle
2
n/a
Electron Transport
32
____________________________________________
(u)2
TOTAL ATP’s
(v)36