Transcript Biochemical Processes

Connect
• Why do we spend time in biology
studying chemicals?
• Why do we have to eat?
• What happens to the food we eat?
• What organic molecules did you
eat today?
• Name a protein, a carb, and a lipid.
Biochemical Processes
♦ All organisms need both energy
and chemicals for survival.
Once chemicals are inside an
organism they are changed in
different ways to maintain
homeostasis.
♦ Because we can’t always use
chemicals the way they exist,
we use the following processes:
1. Digestion
2. Synthesis
3. Respiration
4. Photosynthesis
1. Digestion
• when we eat food the molecules
are too large to enter our cells;
as a result our digestive system
changes the larger molecules
into smaller molecules
Large
Digested to
Small
Carbohydrates
simple sugars (glucose)
Proteins
amino acids
Lipids
fatty acids and glycerol
2. Synthesis
• after digestion you have small
molecules in your cells; some of
these molecules will be put
together to form larger
molecules to make structures
such as hair and nails,
hormones, and enzymes
Synthesis is
the opposite
of digestion.
3. Respiration
• as mentioned previously, after
digestion you have small molecules
such as glucose in your cells. Some
of this glucose combines with
oxygen in the mitochondria of cells
to release energy needed to run the
cell. This energy is stored in ATP.
4. Photosynthesis
• plants and
algae use light
energy to
convert simple
inorganic
compounds into
food which is
organic
• What do plants need?
water + light + CO2
• What do plants make?
food (glucose) + O2
Chunk!
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What do living things need to survive?
Why do the chemicals need to be changed?
Name the 4 processes that change chemicals.
Define digestion. Why is it necessary?
Name the 3 large molecule types, and what
they are digested into.
• Define synthesis. Why is it necessary?
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What happens during respiration?
Where does respiration occur?
What is the energy molecule?
Define photosynthesis.
Enzymes
• None of the reactions described
above could occur without the action
of enzymes known as catalysts.
These important proteins speed up
reaction rates in our bodies without
a high temperature.
Enzymes are used repeatedly to
catalyze reactions.
• Enzymes are catalysts, substances
that speed up the rate of a chemical
reaction without themselves being
changed or used up during the
reaction.
• Enzymes are capable of carrying out
the same function over and over bc
they are not changed.
• You can use this characteristic
of enzymes – that they
themselves are not changed – to
recognize the enzyme in a
diagram.
• Enzymes like other molecules
(hormones, antibodies, receptors on cell
membranes) have specific shapes that
determine how they function.
• Enzymes are chain-like protein
molecules that are folded into precise
shapes.
• Some molecules called substrates
match precisely with the shape of
certain enzymes, others don’t fit.
For example, the enzyme pepsin in
your stomach acts on protein you eat
to digest it.
Pepsin is not effective in digesting
fat.
Chunk
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What is another name for enzymes?
What do enzymes do?
What happens to enzymes during reactions?
Can enzymes be used again?
How can you recognize an enzyme in a
diagram?
• Enzymes, hormones, neurotransmitters, and
antibodies all function by ___________.
Chunk some more…
• The molecule an enzyme works on is
called…
• Why will pepsin just digest protein, nothing
else?
• What kind of molecule is an enzyme?
• Describe the enzyme-substrate complex.
• What are the molecules that are the result
called?
A
D
D
A
C
F
F
B
E
Computer
simulation
of an
enzyme
that works
on oxygen
Move to HBS unit