Unit III - Biochemistry
Hierarchy of Organization
Ecosystem
Community
Population
Organism
Organ System
Organ
Tissue
Cell
Organelle
Molecule
Atom
Why is water so important to life?
What does it do that is so important?
Water allows for easier transport…
Water allows chemical reactions to occur…
■
Most reactions require dissolved chemicals
Water holds heat very well…
■
■
■
Aquatic organisms do not have wild temp change
Coastal habitats have less temp fluctuation
Your body temp does not fluctuate wildly
Frozen water floats on liquid water…
■
Aquatic life is insulated from cold
temperatures when the top layer is frozen
Why water?
Why is it so special?
Electronegativity!
(how hard atoms pull on electrons)
Remember this?
Atoms need 8 electrons on outer shell
(or a full outer shell) to be “happy”
Atoms need 8 electrons on outer shell
(or a full outer shell) to be “happy”
Atoms need 8 electrons on outer shell
(or a full outer shell) to be “happy”
Atoms need 8 electrons on outer shell
(or a full outer shell) to be “happy”
Who wants those electrons more
– H or O?
Atoms need 8 electrons on outer shell
(or a full outer shell) to be “happy”
This
POLARITY
is the reason
why water is so
special!
Do you
remember
these from
yesterday?
Water
Why is Water Important
to Organisms?
❑
❑
❑
❑
Bathes cells
Needed for chemical
reactions
Used for transport
Holds/transfers heat
Water
Why is water so special?
…it has POLARITY
occurs because O pulls
electrons harder than H’s
pull…makes each have a
slight charge
Water
Water’s charged sides attract to other molecules
with charges (it’s kinda “sticky”)
❑
❑
These are called hydrogen bonds
Are weaker than ionic/covalent, but they add up!
hydrowater
Water
■
Water has many special properties, most of
which occur because of the hydrogen bonding
■
As you go through each of the properties be
sure to look for 3 things:
❑
❑
❑
Definition of the property
Why the property happens
Why the property is important to organisms
Water
Special properties:
ADHESION - attraction btwn water & another type
of molecule
- where did you see that on your mini-lab?
COHESION - water sticks to itself
- where did you see that on your mini-lab?
WHY does it happen? Polar (sticky ends) grab
each other
co - together
Water
A special type of adhesion…
capillarity: water “climbs” up thin tubes
Ex: water moves thru tubes in plants and animals
(veins, etc)
Water
A special type of cohesion…
surface tension: forms strong layer; beads up
WHY? hydrogen-bonds make water stick to itself
Ex: bugs on water surfaces; dew droplets gather
on leaves
co - together
Water
Special properties:
high specific heat: - water holds its heat
very well (hard to change its temp)
- must break a lot of H-bonds before
energy can be used to raise temp
- Ex: coastal/aquatic ecosystems &
individual organisms are protected from
wild temp changes, Costal
towns are more humid in temps
Water
Special properties:
high heat of vaporization: - lots of heat is
removed as water goes from liquid to gas
WHY? The hottest molecules leave first & fastest (lowers
the average temperature)
- Ex: sweating
Water
Special properties:
ice floats on water:
- solid H2O is less DENSE
than liquid water
WHY? the H-bonds hold molecules far
apart (more VOLUME)
- Ex: lakes freeze from top down…
insulates aquatic life below
Water
Special properties:
universal solvent: water dissolves many substances
- water will dissolve things that have charges
(ionic & polar covalent compounds)
- Ex: most chemical reactions require aqueous solutions
(dissolved substances)
pH – a measure of H+ ions
scale is 0 - 14
■
■
acids
❑ pH < 7
❑ tend to start with “H”; ex: HCl
bases
❑ pH >7
❑ tend to end in “OH”; ex: NaOH
pH – a measure of H+ ions
Scale is 0 - 14
❑
❑
❑
■
Why pH matters to life –
❑
❑
❑
■
each pH level is 10 times more than next
pH 3 is 10x more acidic than pH 4
pH 3 is 100x more acidic than pH 5
Chemical rxns require specific pH levels
Acid rain affects ecosystems
Some enzymes are broken by extreme pH
Buffers ❑
❑
What? - Chemicals that keep pH stable
Why? - Reactions may not work if at wrong pH
pH – a measure of H+ ions
Bell Ringer
■Finish your reflections
❑Pre-AP= 10-12 sentences on why water is
important to life, and list and describe the water
properties
❑Biology= 6-8 sentences on why water is important
to life, and list (briefly describe) the water
properties
Organic Compounds
■
■
Organic compounds come from organisms
They include 4 major groups:
❑
■
■
■
carbohydrates, lipids, nucleic acids, & proteins
All are very large molecules built from small units
Monomer = building block
Polymer = large molecule
mono - one
poly - many
Organic Compounds
■
■
Monomers can be joined to each other to make
polymers
They are joined by removing water
❑
Called dehydration synthesis (or condensation)
“to make by removing water”
hydr – water
syn - together
Organic Compounds
■
Polymers can be broken apart into monomers
❑
❑
This process breaks larger molecule by adding water
Called hydrolysis “to break with water”
hydr – water
lys - burst
Organic Compounds
Carbohydrates
■
Structure
monosaccharide:
(monomer)
mono- one
poly- many
sacchar- sugar
(C,H,O)
polysaccharide:
(polymer)
Organic Compounds
Carbohydrates
Examples of Simple Sugars
❑
❑
Glucose (simple sugar) - cell
energy
Others:
fructose, dextrose, …
(end in “ose”
Organic Compounds
Carbohydrates
Examples of Polysaccharides
❑
❑
❑
❑
Starch – how plants store
extra glucose
Glycogen – how animals
store extra glucose
Cellulose – makes up cell
walls of plants; dietary fiber
Chitin – makes up cell walls
of fungi/insect exoskeletons
Organic Compounds
Lipids
(C,H,O)
Structure – nonpolar (do not like water)
monomer is the fatty acid chain
Organic Compounds
Lipids
Types:
■ saturated fats – hold as much H as possible;
solid at room temp; animal fats
Organic Compounds
Lipids
■
■
Types:
unsaturated fats – missing H due to multiple
bonds; liquid at room temp; plant oils
Organic Compounds
Lipids
Examples –
❑
Triglycerides – fats & oils
used for long-term energy storage
tri- three
glyc- sugar
Organic Compounds
Lipids
Examples –
phospholipids: have polar side
& nonpolar side; make up cell
membrane
steroids: ringed molecules;
hormones (cholesterol,
testosterone, estrogen)
Organic Compounds
Nucleic Acids (C,H,O,N,P,S)
Monomer is the nucleotide:
Examples: DNA, RNA (genetic
material- hereditary info)
Organic Compounds
Proteins
(C,H,O,N,S)
Monomer is the amino acid:
Organic Compounds
Proteins
Examples: numerous!
❑
❑
❑
❑
Collagen
Hemoglobin
Insulin
Enzymes (pepsin, etc)
Functions – build structures,
enzymes, hormones
Organic Compounds
Proteins
Structure –
simple proteins:
complex proteins:
On page 31- testing unknowns
■Carbohydrate test
❑BENEDICT’S TEST
❑IODINE TEST
■Lipids test
❑PAPER TOWEL TEST
Results from testing
Benedicts and Iodine
Lipids
Biuret test (proteins)
Bell Ringer Activity Page 30
■In your table group, you will be working on
your COMPARING BIOMOLECULES sheet.
■This is for a grade, and you will see this on
your quiz tomorrow as well as your test next
week
Enzymes (Special Proteins!)
■
Enzymes are needed in order to SPEED UP
reactions
The enzyme does NOT get USED in the reaction
■
https://www.youtube.com/watch?v=CZD5xsOKres
■
Enzymes (Special Proteins!)
■
■
■
Enzymes are very SPECIFIC – they only work with
one reaction
Every chemical reaction has at least ONE enzyme
If an enzyme is missing, a DEFECT will result
❑
Ex: ALBINOS are missing enzyme for melanin…lactoseintolerant people are missing LACTASE
Enzymes (Special Proteins!)
■
NAMING ENZYMES
❑ Usually end in “ase” (name usually linked to
substrate)
❑ Note: enzymes do NOT always break down
things…they work for building reactions too!
SUBSTANCES
A
B
ENZYME
PRODUCT AB
ENZYME
Naming Enzymes
■Usually ends with ase
■ Lactase breaks down lactose
■Sucrase breaks down sucrose
■Peptidase/pepsin breaks down protein
■Catalase breaks down water based
compounds (fat soluble, polarity etc)
■Amylase breaks down starch
III. Enzymes (Special Proteins!)
■
■
Enzymes must be in the correct SHAPE or their
substrates will not fit in with them
Unfolding of an enzyme is called DENATURATION
❑ May be caused by BOILING (high heat), or strong
acids/bases (extreme pH’s)
Self-Quiz – Chemistry
■
■
1. Water moving thru tiny tubes is A. capillarity
C. cohesion
B. surface tension
D. specific heat
2. Which of the following is the weakest?
A. ionic bonds
C. hydrogen bonds
B. electrovalent bonds D. covalent bonds
Self-Quiz – Chemistry
■
3. Most of water’s special properties are due
to the fact that it is –
A. polar
■
B. neutral
C. covalent
D. nonpolar
4. Weak attractions between water molecules
are A. covalent bonds
B. H-bonds
C. Ionic bonds
D. nonpolar bonds
Self-Quiz – Chemistry
■
5. To build polymers,
A. monomers are hydrolyzed
B. monomers are broken down
■
C. water is added
D. water is removed
6. Hydrolysis A. builds muscle tissue
B. creates water
C. is used in digestion
D. produces polymers
Self-Quiz – Chemistry
■
7. Crabs in a lake don’t worry about wild temperature
changes in their home because water has A. less density as a solid
B. capillarity
■
C. high specific heat
D. high surface tension
8. Water forms droplets due to its A. covalent bonding
B. cohesion
C. high heat of vaporization
D. hydrolization
Self-Quiz – Chemistry
■
■
■
■
9. What does “polarity” actually mean?
10. What is a “monomer”?
11. What is the monomer for carbohydrates called?
12. Name 2 food sources high in carbs.
The End
Lab – Enzyme Reactions
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■
■
■
I. Purpose: How does a strong acid and high
temperature affect enzyme activity?
II. Background: Enzymes make chemical reactions
go faster.
III. Hypothesis: Strong acid will make an enzyme
reaction go ___. High temp will make an enzyme
reaction go ___.
IV. Procedure: (draw picture)
Lab – Enzyme Rate of Reaction
I. Purpose: How does the level of ___ affect the rate of
reaction involving the enzyme catalase & hydrogen
peroxide?
II. Background: state what you know about the question
(what you know about enzymes, substrate, the variable tested, etc)
III. Hypothesis: An increase in ___ will cause the rate of
reaction to ___.
IV. Procedure: (sketch & label your design)
Lab – Enzyme Rate of Reaction
IV. Procedure: (sketch & label your design)
V. Data: (create your data table and graph axes here)
VI. Conclusion: (must be complete sentences for credit!)
- data summary
- support or not
- SoE
- how to fix
Lab - Denaturation
■
■
V. Data Describe what happened.
VI. Conclusion
Strong acid causes enzyme reactions to…
High temp causes enzyme reactions to…
This effect is called ____________.
Solid water floats…solid oil sinks!