Nutrients Required for Life
1. Water
2. Nitrogen, phosphate and other inorganic compounds
3. Energy source: from oxidation of reduced C molecules or
sunlight
4. Carbon source: reduced C molecules (sugar) or oxidized
ones (CO2)
5. Electron acceptor: like oxygen (not always oxygen)
Nutrients Required for Life: Water
The unique structure of water molecules makes it:
1. Stick together (plants)
2. Tolerate heat
3. Excellent solvent
Nutrients Required for Life: Inorganic Molecules
NITROGEN, PHOSPHATE AND OTHER INORGANIC MOLEC.
proteins
nucleic acids (RNA,
DNA)
Nutrients Required for Life: Energy Source
The direct energy source of ALL cells in ALL organisms is ATP!
Adenine
Phosphate
groups
Ribose
What kind of molecule does this remind you of?
Nutrients Required for Life: Energy Source
What Makes ATP a high energy molecule?
ATP
water
Hydrolysis Reaction:
Water breaks bond of the
3rd phosphate
ADP
inorganic
Energy
phosphate
Exergonic Reaction:
Releases energy
Nutrients Required for Life: Energy Source
Released energy used to fuel endergonic reactions
•Polymerization of nucelotides to make
DNA
•Transcription (DNA to RNA)
•Translation (RNA to amino acid chain)
•Polymerization of amino acids to make
proteins
•Contraction of muscle cells
•Transmission of nerve impulses
Nutrients Required for Life: Energy Source
The cleaved phosphate regulates cellular reactions
It binds amino acids on proteins  change in protein shape 
(de)activation of proteins
For example:
Membrane proteins
Enzymes and substrates
Nutrients Required for Life: Energy Source
Conformation of enzymes and substrates must be exact for them
to interact and result in a reaction
Enzyme cannot bind
its substrate in this form
Now, it can.
Nutrients Required for Life: Energy Source
Cells are good at making ATP, but do not always have a
reserve supply of ATP ready to be hydrolyzed whenever
the cells need energy
ATP is not very stable
An ATP molecule stable for about 30-90 seconds
When a cell needs ATP, it needs to generate it
How is ATP
generated?
Phosphate
groups
Adenine
Ribose
Nutrients Required for Life: Energy Source
To make ATP:
Essential
nutrient
+
ADP
+
phosphate
Energy
?
ATP
• 10,000,000 ATPs generated/min in
each cell!!!
• Where does the cell get all the
energy to do that?
Nutrients Required for Life: Energy Source
Energy from bonds in
highly reduced molecules
(=sugar)
Eating some type of high energy carbon molecule like sugar: C6H12O6
Nutrients Required for Life: Energy Source
C6H12O6 is a reduced molecule
•High energy stored as electrons in
the many C-H bonds
•Breaking those bonds releases the
energy
•BUT, those electrons have to go
somewhere- to another molecule
•This other molecule is called the
“electron acceptor”
This is what happens during
Cellular Respiration
•Sugar is the “electron donor”
Nutrients Required for Life: Energy Source
Energy from Reduced Carbon Molecules is released when they
Are broken down in the presence of oxygen (oxidized)
“Cellular Respiration”
e- donor e- acceptor
C6H12O6 +
6O2 +
ADP + Pi + energy  ATP
CO2 +
6 H20 +
energy
heat
Nutrients Required for Life
1. Water

2. Nitrogen,
phosphate and other inorganic compounds

3. Energy source: from oxidation of reduced C molecules
or

sunlight
4. Carbon source: reduced C molecules (sugar) or oxidized
ones (CO2)
5. Electron acceptor: likeoxygen (not always oxygen)
Nutrients Required for Life: Energy Source
Animals get their sugar from plants.
Plants use their own sugar for cell respiration
But, in order to make the sugar, they need another form of energy
not required by animal cells
Generation of that reduced C molecule requires energy
+
CO2
+
H2O
C6H12O6
+
O2
Nutrients Required for Life
1. Water

2. Nitrogen,
phosphate and other inorganic compounds

3. Energy source: from oxidation of reduced C molecules
or

sunlight

4. Carbon source: reduced C molecules (sugar) or oxidized
ones (CO2)
5. Electron acceptor: likeoxygen (not always oxygen)
Nutrients Required for Life: Carbon Source
Aside from needing carbon molecules (sugar) to generate ATP,
also need to take in carbon from their environment to use as a
building block to make C-containing molecules (amino acids,
lipids, nucleotides)
Animals use reduced C molecules
(sugar) from plants for both their
energy molecule and C building block
What about plants? They don’t take in
Sugar from their environment so what
C molecule do they take in to use for
Building new C molecules including
Sugar made during photosynthesis?
Nutrients Required for Life
1. Water

2. Nitrogen,
phosphate and other inorganic compounds

3. Energy source: from oxidation of reduced C molecules
or

sunlight

4. Carbon source: reduced C molecules
(sugar) or oxidized

ones(CO2)
5. Electron acceptor: likeoxygen (not always oxygen)
True or False
1. Plants use CO2 as their carbon source for building new C molecules AND
as their high energy molecule (that is used in cell respiration to generate ATP)
2. Plants use CO2 as their carbon source for building new C molecules and
sugar as their high energy molecule (used in cell respiration to generate ATP)
3. To build new carbon-containing molecules, plants and animals must take in
sugar by eating other organisms
4. Plants require sunlight in order to generate the high energy carbon molecule,
CO2
5. When the reduced carbon molecule, sugar, is broken down, the energy
released is used to make ATP from ADP and P
6. O2 is necessary b/c it donates its electrons to glucose during cell respiration
7. Both plants and animal cells require 2 forms of energy: sunlight and
reduced C molecules