Wed Sept 13
• Review worksheet covering objectives for
cell respiration, after 1st...
• Wrap up enzyme function (as an example
of modulating protein function)
• You might remember from last time: 3 D
shape of protein is key to function
Multi-enzyme pathways & Regulatory
Enzymes
e4
Int-4
e3
Int-3
e2
Int-2
Threonine
e1
Int-1
• In bacterial cells a multiple enzyme pathway is
involved in generating isoleucine from threonine
• Why regulate this?
• How could one regulate this, most efficiently?
• Also see fig 3.39
e5
Isoleucine
• What is
glycolysis and
where does it
occur?
• How many ATP
are produced
(gross) by
glycolysis for
each glucose
molecule that is
metabolized?
• How many are
used up?
• What is the net
ATP production
for this set of
reactions?
• What are the electron carrying coenzymes that are
modified during glycolysis and what is their
relevance to cellular respiration?
• In the presence of oxygen how many of each of the
reduced coenzymes are produced (per glucose)?
• With oxygen the carbons from the original glucose
exit glycolysis as what molecule?
• How many (per glucose)?
•
Without oxygen how many of each of the reduced coenzymes are
produced during glycolysis?
─
Without oxygen the carbons from the original glucose exit glycolysis as what
molecule?
─
How many?
─
Why are there differences in the end products of glycolysis based on oxygen
availability?
• In the presence of oxygen, what molecule or molecules
enter the citric acid cycle?
─ What is/are the molecular precursor(s) of this/these molecule(s)?
• Where in the cell does the citric acid cycle occur?
•For every
glucose that
began
glycolysis...
─...how many of
each type of
reduced
coenzyme is
produced during
the citric acid
cycle?
─...how many of
what waste
products are
produced?
─...how many ATP
are produced from
the Krebs cycle?
•
How is ATP produced by electron
transport/oxidative phosphorylation?
─ Does glucose go straight into this process?
─ What is the role of reduced coenzyme?
─ What is the role/inter-relationship of/between
proton pumping/matrix/intermembrane
space/proton gradient/diffusion of
protons/ATP synthase?
http://www.wiley.com/legacy/college/boyer/0470003790/animations/elec
tron_transport/electron_transport.htm
• For every glucose that starts glycolysis,
how many ATP are produced by electron
transport/oxidative phosphorylation?
─Note:
NADH
=
3 ATP
FADH2
=
2 ATP
Oxygen is used to form H2O
Prior steps yielded 10 NADH + H+ & 2 FADH2 /
glucose
To Summarize Energy Production
per mole glucose (Aerobic)
• Cytosolic
2 NADH + H+
2 ATP
• Mitochondrial
─Branch Point
2 NADH + H+
─Citric Acid Cycle 6 NADH + H+
2 ATP
2 FADH2
─Oxidatative Phos.
•
34 ATP
Total:
38 ATP
• The metabolism of a
certain triglyceride
(storage fat) produces
glycerol and three fatty
acids for a total of 28
acetyl-CoA molecules.
In the presence of
oxygen, how many ATP
will be produced from
this triglyceride?
• Pantothenic acid is one of the B-complex
vitamins and as such is one of many
essential nutrients required for normal
functioning of our metabolic processes.
─A) What is an essential nutrient?
─B) In terms of cellular respiration, what is the
importance of pantothenic acid?