Transcript Basic Chemistry Review

When two or more atoms bond
together, a/an __________ is
formed.
A. Cell
B. Ion
C. Organelle
D. Molecule
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Biochemistry Intro Notes
• We are going to start studying life on
the smallest level, a level so small
you cannot even see with a regular
microscope…
• A Molecular Level….
• http://learn.genetics.utah.edu/content/begin/cells/scale/
Matter
• Matter is anything that has mass
and takes up space
• Matter is made up of different
elements (periodic table)
– Does the air in this room contain
matter? Why?
Elements
• Elements are pure substances
that consist entirely of one type of
atom.
• Elements are represented by
one or two letter chemical symbol.
– What chemical symbol represents
carbon? Helium?
Which of the following contains only
one element?
A. NaCl
B. C6H12O6
C. H2O2
D. O2
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Main Elements in Living
Matter
• 90% of all living matter is composed
of just 4 elements
–Carbon
C
–Hydrogen H
–Oxygen O
–Nitrogen N
–97% with Phosphorous (P) and
Sulfur (S)
Atoms necessary for life
Molecules
• Molecules form when two or
more atoms bond or
associate together
• Molecules have different
properties than the elements
that make them up.
Sodium (Na+)
Chlorine (Cl-) (gas)
+
Table Salt (NaCl)
Practice
• Which of the following are molecules?
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H2SO4
CO2
H 2O
O2
How many atoms are in H2SO4
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Chemical Reactions
• Chemical reactions rearrange bonds
– Nothing is created nor destroyed, just
rearranged
• Reactants  products
Practice
• What are the reactants?
1. 4Al + 3O2  2Al2O3
2. 2 N2O5  4 NO2 + O2
• What are the products?
1. CaCO3  CaO + CO2
2. 4H2(g) + O2(g)  2H2O(l)
Metabolic Reactions
• Catabolic reactions:
• Break down complex
molecules into
smaller ones
• Releases energy
• Forms waste
• Fuels anabolic
reactions
• Ex. Digestion, cellular
respiration
• Anabolic reactions:
• Build complex
molecules from
simpler ones
• Needs an energy
input
• Necessary for growth
• Ex. Protein synthesis,
photosynthesis
Catabolic fuels anabolic
Solutions
• Your cells and the fluid
surrounding your cells is a
solution
• Solution = solute + solvent
• Solute = the molecules
dissolved in the solvent
• Solvent= what dissolves
the solute
• Ex) saltwater is a solution
made of salts (solute) and
water (solvent)
• Water is the most common
solvent
Water, H2O, is essential for all
life on earth
Properties of water
• Water is a polar
molecule
– Has uneven sharing of
electrons between
oxygen and hydrogen
• Because water is
polar, it forms weak
bonds (called
hydrogen
bonds)between
individual water
molecules
Properties of water
• Because water is polar and can form
hydrogen bonds between molecules,
water has important properties as a result:
– Cohesion
• Can stick to other water molecules
– Adhesion
• Sticks to other polar molecules
– High specific heat
• Takes a lot of energy to change temperature
– Universal solvent
• Can dissolve all polar substances
Water. Its important!
• Water transfers dissolved nutrients and waste throughout a
living system
• Water dissolves molecules such as salts into ions which are
used in various cellular activities
• High specific heat allows for thermoregulation.
• Evaporation of water releases sufficient heat to cool down
an organism
• Chemical reactions occur in water due to water’s ability to
dissolve/break apart the reactants and bring the products
together
• Living tissues are ~ 70% water by weight, 25%
biomolecules, 5% ions and small molecules
Organic molecules
• Organic molecules- molecules that contain
carbon atoms
– Exceptions: carbon dioxide (CO2), Calcium
carbonate (CaCO3), and plastics
• Biomolecules – organic molecules built
and used in living organisms
• Organisms are “organic” meaning carbon
based
Organic molecules
Molecule with all atoms
shown
Same molecule with
carbon chain not shown
Every point has a carbon atom
Organic molecules
• Glucose is an organic
molecule
• Formula: C6H12O6
• Forms a ring structure
when placed in water
• Ring structure
diagram does not
directly show carbon
atoms. One atom at
each point.
Biomolecules
• The 4 main classifications of biomolecules
are
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
How are biomolecules made or
broken down?
• Through chemical reactions:
– Sucrose  Glucose + Fructose
– Amino acid + amino acid  Polypeptide
Biomolecule formation
• Monomer – a molecule that tends to link
with other molecules of its kind to form a
chain
• Polymer – a large molecule made up of
repeating monomers
– Monomer + monomer + monomer = polymer
• The four main biomolecules each have
monomers and polymers
Biomolecule formation
• Polymers are built through dehydration
synthesis (or condensation) reactions
which bond two monomers together
• Polymers are broken down into individual
monomers through hydrolysis reactions
• In digestion, the polymers in your food are
broken down through hydrolysis and then
rebuilt through dehydration reactions in
your cells
• Dehydration (condensation) reaction summary:
• Monomer + monomer  polymer + H2O
• An OH group from the end of one monomer bonds with a H from the
end of another monomer
• A water molecule is lost from the reactants and is formed as a product
(condenses out)
• A bond is formed between the 2 open atoms on each end of the
monomers to form a polymer
Dehydration/condensation
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Polymer decomposition through hydrolysis
H2O + polymer  monomer + monomer
A water molecule is added to break the bond
The OH group from the water molecule bonds with the end of one
monomer and the H bonds with the end of the other monomer
• This breaks the bond between the two monomers
Polymers
• The properties of polymer molecules are
determined by the individual monomers and
their arrangement
Practice
1. Is this hydrolysis or dehydration
synthesis?
a)
b)
Draw it out
• Draw 3 monomers joining together in a
bond through dehydration synthesis.
• Draw 1 polymer breaking apart to 3
separate monomers through hydrolysis.