Energy and Life

1
Energy Metabolism
2
Matter Energy

• Matter- anything that takes up space and has mass
• Energy- the ability to do work
• Kinetic (energy in motion)
• Potential (stored)

3
Energy takes on different forms in the body

• Chemical- ATP?ADP Pi (glycolysis)
• Mechanical- muscles moving, producing heat,
  digestion
• Electrical- charges particles Na/K, Ca,
  nerve and muscle
• Radiant (electromagnetic)- energy that travels
  in waves (visible, UV, IR) ? Retina,
  light?skin?vitamin D

4
Consequences of This Energy (Work)

• Maintaining Homeostasis
• Reproduction, Development Growth
• Movement

5
Potential vs Kinetic Energy
6
Potential Energy Stored energy
7
Potential Energy Chemical Energy
8
Kinetic Energy Energy in motion
9
Kinetic Energy Molecular Motion
10
Exergonic vs Endergonic Reactions

• Endergonic- A nonspontaneous chemical reaction
  where energy is absorbed from the surroundings

• Exergonic- A spontaneous chemical reaction where
  there is a net release of free energy

11
Endergonic Reactions
6CO2 6H2O energy ? C6H12O6 6O2 ADP Pi
energy ? ATP
Energy

Product
Reactants
12
Exergonic Reactions
C6H12O6 6O2 ? 6CO2 6H2O energy ATP ?
ADP Pi energy
Energy released
Reactants
Products
13
ATP
14
Hydrolysis of ATP
ATP ? ADP Pi energy
15
Enzymes

• Catalysts- speed up a reaction
• Not used up by reaction
• Decrease activation energy of a reaction
• (activation energy is needed to break chemical
  bonds)

Enzymatic reactions are affected by

• Temperature
• pH
• Substrate conc.
• Enzyme conc.

16
Enzymes
Are very specific for their substrate
Substrates Bind only to a
restricted region of the enzyme (active site)
Held in place by weak interactions
(H-bonds)
Active site
Substrate (sucrose)
Enzyme (sucrase)
Specificity of enzyme
Lock and key
17
The Functioning of Enzymes
active site
18
Activation Energy
19
Activation Energy
20
Regulating Enzyme Activity
Enzyme
21
Regulating Enzyme Activity
22
Metabolism

• The sum total of the chemical processes that
  occur in living organisms, resulting in growth,
  production of energy, elimination of waste
  material, etc.
• Anabolism- build up of complex molecules
• Catabolism- break down of complex molecules

23
Fates of Organic Building Blocks in ATP Metabolism
ORGANIC BUILDING BLOCK MOLECULES Monosaccharides A
mino acids Acetates Nucleotide bases
ATP
energy
catabolic processes
energy
anabolic processes
ADPPi
Polymers other energy rich molecules
CO2 H2O
24
Cellular Respiration
C6H12O6 6O2 36ADP 36Pi ? 6CO2
6H2O 36ATP
25
Basic Steps Involved
1
Glycolysis
2
Acetyl CoA Formation
3
Krebs Cycle
4
Electron Transport System
26
Overview of Glycolysis
27
Fats
Glycogen
Protein
Other Metabolic Pathways
28
Glycolysis
29
Glycolysis
P
ATP
ADP
ADP
ADP
NAD
P
H
P
ADP
ATP
NAD
Glucose
H
P
2 pyruvate
ATP
NADH
ATP
ADP
ATP
P
ATP
NADH
ADP
P

• Net
• 2 ATP
• 2 NADH
• 2 Pyruvate molecules

Cystol
30
Balance Sheet for Glycolysis

• Input
• 1 Glucose
• 2 ADP Pi
• 2 NAD
• Output
• 2 Pyruvate
• 2 ATP
• 2 NADH

ADP
ADP
P
P
NAD
NAD
ATP
ATP
NADH
NADH
31
Transition Reaction
2 pyruvates
NAD
CO2
CoA
NADH
H
2 Acetyl CoAs
32
2 Acetyl CoAs
Transition Reaction
CoA
FADH2
Krebs Cycle
2
CO2
FAD
3NAD 3H
NADH
NADH
ATP
NADH
3
ADPPi
33
Krebs Cycle
34
Balance Sheet for the Transition Reaction and
Krebs Cycle

• Input
• 2 Pyruvate
• 2 ADP 2 Pi
• 8 NAD
• 2 FAD

• Output
• 6 CO2
• 2 ATP
• 8 NADH
• 2 FADH2

35
Krebs Cycle
Handles other substrates Intermediate molecules
used proteins and lipids Replenishment of
intermediates necessary
Hans Krebs (1937) paper originally rejected
36
Krebs Cycle
Takes 2 complete cycles 8 steps, each with an
enzyme
37
3
Krebs Cycle
38
Oxidative Phosphorylation
http//vcell.ndsu.nodak.edu/animations/etc/movie.h
tm
39
Each Glucose Molecule
CO2 6 NADH 10 FADH2 2 ATP 4
40
Electron Transport System
CO2 6 NADH 10 FADH2 2 ATP 4
used to make ATP
41
4
Electron Transport System
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Electron Transport System
43
(No Transcript)
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Net ATP Yield
34 to 36 molecules ATP for every glucose molecule
about 40 efficiency
45
Transition cycle
46
Overall ATP Production
Electron Transport System 34 Citric Acid
Cycle 2 Glycolysis 2 SUBTOTAL 38 NADH Transport
into Mitochondrion -2 TOTAL 36
47
Fermentation (Anaerobic Respiration)
48
Anaerobic Respiration (Lactic Acid Fermentation/
Glycolysis)
49
INQUIRY

1. What is the end product in glycolysis?
2. What substance is produced by the oxidation of
   pyruvate and feeds into the citric acid cycle?
3. Name a product of fermentation.
4. What role does O2 play in aerobic respiration?
5. What stage during cellular respiration is the
   most ATP synthesized?
6. What is chemiosmosis?
7. When NAD and FAD are reduced what do they form?
8. What are they used for?