Download CHAPTER 5 Energy and Life.

CHAPTER 5 ENERGY AND LIFE
1.
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.
2.
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
Carbonic Anhydrase
enzyme
Carbonic Anhydrase from the Marine
Diatom
Thalassiosira weissflogii
Carbonic Anhydrase from
the Marine Diatom Thalassiosira weissflogii
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-
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.
A model of an enzyme attaching to a substrate.
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.
Cells Transfer Glucose energy by converting the energy into an cell energy
Transfer molecule called ATP – Adensine Triphosphate.
STARCH -> Enzyme action to get Glucose -> Enzyme action to get ATP
There is also Carbon Dioxide and Water too.
When ATP is broken down by cell enzymes:
ATP -> 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.
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.
+ 12 H2O + light → C6H12O6 + 6 O2 + 6 H2O
This is the equation for the Calvin Cycle.
6 CO2
carbon dioxide + water + light energy → glucose + oxygen + water
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:
1.
2.
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.
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.
1.
FERMENTATION: IS ANAEROBIC…it 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.
2.
OXIDATIVE RESPIRATION: IS AEROBIC…IT DOES need
oxygen. This is also called the KREBS CYCLE. This takes place
in the MITOCHONDRIA of the cells.
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.
Fermentation in cells. When
You need a Quick boost of
Energy. Think about how
You get out of breath. You
Build an OXYGEN DEBT.