Download Fill in the Captions AP Lesson #26 Are our diets only glucose? How

Fill in the Captions
AP Lesson #26
EQ: How does metabolism utilize
other organic compounds and
regulate cellular respiration?
2
2
~32
Are our diets only glucose?
How do we get energy from other carbs?
• Glycolysis accepts a wide range of
carbohydrates fuels
polysaccharides → → → glucose
hydrolysis
• ex. starch, glycogen
other 6C sugars → → → glucose
Modified by enzymes
• ex. galactose, fructose
How can we get energy from Proteins?
proteins → → → → → amino acids
How do we get energy from lipids?
fats → → → → → glycerol + fatty acids
hydrolysis
hydrolysis
glycerol (3C) → → G3P → → glycolysis
waste
H O
H
| ||
N —C— C—OH
|
H
R
amino group =
waste product
excreted as
ammonia, urea,
or uric acid
fatty acids → 2C acetyl → Acetyl → Krebs
groups
CoA
Cycle
glycolysis
Krebs cycle
2C sugar =
carbon skeleton =
enters glycolysis or
Krebs cycle at
different stages
3C glycerol
enters
glycolysis
as G3P
2C fatty acids
enter
Krebs cycle
as acetyl CoA
1
Which has more energy, carbs or fats?
• Coordination of chemical
processes across whole
organism
• Fat generates 2x ATP vs. carbohydrate
– more C in gram of fat
• more energy releasing bonds
• takes longer to digest = slower release of energy
– digestion
• catabolism when organism needs
energy or needs raw materials
– more O in gram of carbohydrate
• so it’s already partly oxidized
• less energy to release
What is metabolism?
– synthesis
• anabolism when organism has
enough energy & a supply of raw
materials
fat
carbohydrate
– by regulating enzymes
CO2
• feedback mechanisms
• raw materials stimulate production
• products inhibit further production
What role does
digestion play in
metabolism ?
What role does
synthesis play in
metabolism ?
• enough energy?
build stuff!
• cell uses points in
glycolysis & Krebs cycle
as links to pathways for
synthesis
• Digestion
– run pathways “backwards”
• have extra fuel, build fat!
CO2
pyruvate
→ → glucose
Krebs cycle
intermediaries
acetyl CoA
Remember Feedback Inhibition
• Regulation & coordination
of production
– final product is allosteric
inhibitor of earlier step
– no unnecessary
accumulation of product
– production is self-limiting
→
X
1
→
A→B→C→D→E→F→G
→
– ATP is only good as short
term energy
– Feedback inhibition
→ → fatty acids
→
• Feedback Control
amino
acids
→
How do we make sure that we don’t have
ATP just hanging around?
→→
→
– Catabolism of
carbohydrates, fats &
proteins
• all break down through
same pathways
• enter at different points as
intermediates
– cell extracts energy from
every source
2
3
4
5
6
enzyme enzyme enzyme enzyme enzyme enzyme
allosteric inhibitor of enzyme 1
2
How is metabolism similar to an
economy in living things?
How is ATP production
regulated?
• Phosphofructokinase
• Basic principles of supply & demand regulate
metabolic economy
– allosteric regulation of this
enzyme
• why here?
“can’t turn back” step before
splitting glucose
– balance the supply of raw materials with the products
produced
– these molecules become feedback regulators
• they control enzymes at strategic points in
glycolysis & Krebs cycle
– AMP & ADP stimulate
– ATP inhibits
– citrate inhibits
• Balancing synthesis with availability of both
energy & raw materials is essential for survival!
Why is this regulation important?
Balancing act:
availability of raw materials vs.
energy demands vs. synthesis
Summarizing Strategy
• Acrostic – Cell Respiration
C
E
L
L
– a short phrase or sentence that begins with each
letter of the vertical word and offers important
information or key characteristics about the topic.
Assessment
HW: Complete Case Study #3
R
E
S
P
I
R
A
T
I
O
N
Fill in the Captions
2
2
~32
Fill in the Captions
2
2
~32
3