Download Note sheet Chap 5, Sect 3

Chapter 5, Section 3
The main point of photosynthesis is to produce __glucose__, which is then used
_______________.
Most of our energy comes in the form of _ATP_, which is produced more efficiently in
the presence of __oxygen___. This is called __aerobic respiration__.
Where does this occur? mitochondira
The process of getting/harvesting energy from organic compounds is known as
___cellular respiration____.
The equation for cellular respiration:
C6H12O6 + 6O2
 6CO2 + 6H2O + energy
Glucose oxygen carbon dioxide water
ATP
2 Stages of Cellular Respiration:
Stage 1: Break down of glucose
The primary fuel for cellular respiration is __glucose__, which comes from the
breakdown of __carbohydrates__.
Glucose is broken down in the __cytoplasm__ during a process called ___glycolysis___,
which is an enzyme assisted __anaerobic_ process (means no oxygen needed) that
breaks down _1- 6 carbon molecule_ to __2 – 3 carbon molecules_called pyruvate.
As glucose is broken down, __H atoms_ are transferred to _NAD+_ - forming _NADH__.
See diagram on page 105 (figure 11)
Summary:
Glycolysis uses__2__ ATP but produces __4 _ATP, for a net of __2 ATP___.
Another set of reactions produces __2__ NADH.
Stage 2: Production of ATP
Can occur with or without __0xygen__.
With oxygen:
The __pyruvate____ produced during glycolysis enters __mitochondrion___ and is
converted to a __2 – carbon __ compound – producing __1 – CO2____, __1 - NADH___,
and __1 – 2 carbon acetyl group__ (which then attaches to a __coenzyme A__ and is
called __acetyl-CoA______)
The Kreb’s Cycle- series of enzyme assisted reactions
(occurs in the liquidy part of the __mitochondria__)
See diagram on page 106 (figure 12)
Summary:
_Acetyl-CoA__ compound enters the cycle, a __4-_carbon__ compound continues
around the cycle while: __2 – CO2__ are released.
__3__ NADH; __2__ ATP; and __1___ FADH2 (another electron carrier) are produced.
The __NADH___ and ___FADH2____ are electron carriers and store energy.
Electron Transport Chain
Electrons donated by __NADH__ and __FADH2__ pass to an electron transport chain in
the _folds__ of the __mitochondrion_____.
___H+ ions___ are pumped across the membrane: forming __H2O__ when combine
with oxygen ; and help to produce __ATP____.
A total of __up to 34____ ATP are produced for each molecule of glucose.
Without oxygen:
Fermentation – breakdown of carbohydrates in the absence of oxygen
NAD+ is recycled to continue making ___ATP____ through glycolysis.
Does not make it into the mitochondria. (no Kreb’s Cycle)
2 types of Fermentation:
1. Lactic Acid
Occurs in ___animal cells______ - produces __lactic acid__ and __ATP____.
Build up causes muscle soreness/fatigue
2. Alcoholic
Occurs with ___yeast cells__ - produces __ethanol____ and ___ATP_____.
Used for many food and beverages
So a total of __uo to 38___ ATP are produced in cellular respiration.
Which is more efficient? Aerobic or anaerobic
Why? Aerobic is more beneficial – more ATP from harvested from each glucose