CHAPTER 5 ENERGY AND LIFE

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• CHAPTER 5 ENERGY AND LIFE
• Chemical Reaction A chemical reaction
• Involves the making of bonds between atoms.
• Energy can be absorbed or released in chemical
• Reactions. Chemical reactions In the body is
  called METABOLISM.
• Enzymes are organic Catalysts that provide
• Energy to start a chemical reaction. Enzymes
• Speed up chemical reactions.
• Carbonic Anhydrase is an enzyme that helps remove
  Carbon Dioxide from blood. Carbon Dioxide is
  converted to Carbonic Acid.
• Without this enzyme 200 molecules ? per hour
  per liter
• 
  of water
• With this enzyme 600,000 molecules ? per second
  per
• 
  liter of water

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Carbonic Anhydrase enzyme
Carbonic Anhydrase from the Marine Diatom
Thalassiosira weissflogii
Carbonic Anhydrase from the Marine Diatom
Thalassiosira weissflogii
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The enzyme carbonic anhydrase catalyzes the
hydration/dehydration reaction CO2 H2O
H2CO3 The reaction for dissociation of H2CO3
into its constituent ions H2CO3 H HCO3-
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Substrate Enzymes rely on shapes. Substrates
are specific Sites on a molecule where enzymes
bind.
Shape is important When it comes to Enzyme
action. Think Of the enzymes as being Like
KEYS that can Fit into specific sites.
The Site where the enzyme Binds is called an
active Site and the molecule to Which the enzyme
binds Is called the SUBSTRATE.
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A model of an enzyme attaching to a substrate.
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Cells have THOUSANDS of DIFFERENT Enzymes.
Enzymes can be Different in different cells.
Cells can have SPECIFIC purposes. For Example,
Heart Cells, Nerve Cells and even the cells of
the EYES have Different enzymes which affect
different chemical reactions. Heat, Acidity and
Enzyme concentration affect Enzyme function. If
the human body temperature reaches 112 degrees F
many enzymes Are destroyed. Even a
temperature of 105 degrees F affects
enzymes. Eating an all protein diet can affect
the acidity of the blood causing Enzyme problems.
Pepsin Enzyme is an enzyme that helps digest
food and can exist in a High acid environment.
Pepsin is found in the human stomach.
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Cells Transfer Glucose energy by converting the
energy into an cell energy Transfer molecule
called ATP Adensine Triphosphate. STARCH -gt
Enzyme action to get Glucose -gt Enzyme action to
get ATP There is also Carbon Dioxide and Water
too. When ATP is broken down by cell
enzymes ATP -gt ADP P Energy for the
cell. ADP - Adensine Diphosphate
P - Phosphorus The ATP molecule is
composed of One Sugar One Adenine group

and 3 Phosphate groups.
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PHOTOSYNTHESIS Some plants can absorb energy
from the sun to produce ATP and
Carbohydrates. There are Three Stages to
photosynthesis 1. Energy Capture (the
light reactions) 2. Using this energy to
make ATP. 3. ATP is used to make
Carbohydrates. (The Calvin Cycle-called the Dark
Cycle). In this cycle Carbon Dioxide is
important.

6 CO2 12 H2O light ? C6H12O6 6 O2 6
H2O This is the equation for the Calvin Cycle.


carbon dioxide water light energy ? glucose
oxygen water

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• In Photosynthesis PIGMENT molecules absorb energy
  from the sun. In your
• Own eyes the pigment cells, Retinal absorb light
  energy so you can see.
• In plants the MAJOR pigments are
• CHLOROPHYLL. These pigments absorb RED and BLUE
  light. Plants look
• green
  because Chlorophyll REFLECTS GREEN LIGHT.
• Carotenoids. These pigments absorb yellow
  and orange light.
• COLD Temperatures break down
  CHLOROPHYLL. This is why is the fall you
• can see the Carotenoid pigments.
  Think of all the yellow, orange and even red
• colors you can see in the leaves
  during the fall.

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• In animal cells no photosynthesis can take place.
  Euglena protists are an
• exception. Animals rely on FERMENTATION and
  on OXIDATIVE
• RESPIRATION to power their cells.
• FERMENTATION IS ANAEROBICit DOES NOT need
  oxygen.
• This is thought to be an ANCIENT way
  for a cell to operate and
• suggests that CELLS were at one point
  able to survive on an Earth
• with little of NO oxygen on it. This
  takes place in the CYTOPLASM
• of the cell.
• OXIDATIVE RESPIRATION IS AEROBICIT DOES need
• oxygen. This is also called the
  KREBS CYCLE. This takes place
• in the MITOCHONDRIA of the cells.

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In both Fermentation and In Oxidative
Respiration(Krebs Cycle) Glucose Is broken down
into the compound PYRUVATE. This initial
process is Called GLYCOLYSIS.the breakdown of
GLYCOGEN(GLUCOSE). Lysis Means to BREAK
DOWN. Glucose ?undergoes Glycolysis(ENZYMES) ?
Pyruvate Pyruvate can undergo Fermentation or
Oxidative Respiration. Pyruvate ? Fermentation
?Lactic acid(causes leg cramps) ethyl alcohol
Carbon


Dioxide Pyruvate ? Oxidative Respiration ?
36 ATP molecules.
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Fermentation in cells. When You need a Quick
boost of Energy. Think about how You get out of
breath. You Build an OXYGEN DEBT.
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