Transcript Chapter 3: Section 3.2

Biochemistry Notes
Part 2
Biochemistry: is the study of
the molecules that make up
living organisms.
Organic Chemistry
• organic-all substances that contain
both
C & H
Hydrogen
Carbon &
Organic Compounds
• Also called macromolecule
•
Macro-=large
More on Macromolecules
• Monomer: single subunit of
macromolecules
– ONE Lego
• Polymer: many subunits
combined making
a macromolecule
– More than ONE Lego
Organic Compounds
• 4 different types:
–Carbohydrates
–Lipids
–Nucleic Acids
–Proteins
Organic Compound # 1
• Carbohydrates
– composed of C, H, O
– usually 2 H for every C
– monomer is a monosaccharide
– Names end in -ose
– energy sources and structure.
• quick & primary energy source
• Cellulose for a plant cell wall
• Important external cell markers
• Structurally important in living organisms
Carbohydrates saccharide=sugar
• monosaccharide-simple sugar
– Also called simple sugars
– examples: glucose, fructose,
ribose in (RNA)
+
• disaccharide-2 sugars
– examples: sucrose (table sugar),
lactose (milk sugar), and maltose
(grain sugar)+
+
Carbohydrates saccharide=sugar
• polysaccharide-many sugars (long
chains)
– Important source of nutrition & structure
both for quick use and stored energy
– examples: starch (plant storage), cellulose
(plant structure=fiber), and glycogen
(animal storage)
+
+
Starch is made up of many Glucoses
Starch
Glucose
(C6H12O6)
Carbohydrate Functions
What is a Reaction??????
• A sequence of events where chemicals
are changed
• Involve reactant(s)  product(s)
• Reactants “react” to form or produce
“products”
• Other occur spontaneously and produce
energy exergonic
• Some reactions NEED energy to
occurendergonic
How do monomers become polymers?
• Dehydration synthesis: synthesis (to build
from smalllarge)
– also called condensation reaction
– when monomers are put together, each
bond that is built releases a water molecule
• Hydrolysis: -lysis (to break down from
largesmall)
– water added (water=hydro- )
– this is how monomers are broken apart
1. 2 H’s and a O are
removed from the
monomers (the smilies
are the monomers)
2. Remaining
O joins with
the two
monomers
1. Water molecule is inserted
at the O, breaking the O bond
Testing for Macromolecules
• Different reagents (or indicators) are
used to test for macromolecules.
• Reagent- a substance used to produce
a chemical reaction to detect a specific
substances
Carb Food Test (#1-Simple Sugar)
•
•
•
•
Two different types of carb tests!!
Reagent—Benedict’s solution
Special because it needs to be heated (endergonic)
After heating results can be:
– Positive test—orange, green, or brown color
– Negative test—solution remains blue
Carb Food Test (#2-Complex sugar)
• Reagent—Iodine
• Positive test—blue/black color
• Negative test—will stay golden color of
iodine
Organic Compound #2
• Lipids (Fats)
– composed of C, H, O
– The monomers of tri or diglycerides are
fatty acids(2 or 3) and 1 glycerol
– If they are a wax or steroid then they do
not have monomers, but are big bulky
molecules
– store energy, most of cell membrane,
insulation, water proofing and cushions
organs
Lipids
• Examples:
– Hormones like testosterone and
estrogen (steroids)
– Waxes-cuticle of a leaf, ear wax
– Oils-unsaturated fats in plants
– Phospholipids in cell membrane
• They are almost always hydrophobic
(water=hydro) (fear=phobic) so do not mix
with water, also making them nonpolar
Lipids
•
They are almost always hydrophobic
(water=hydro) (fear=phobic) so do not
mix with water, also making them
nonpolar , so
• so solubility in water is an identifying test
• Brown paper is another test
Lipids- Identifying Tests
• Solubility
• Brown paper
Lipids
• Some lipids are made of a glycerol and
3 fatty acids (triglycerides)
What is this called?
Lipids
• Phospholipids
Lipids
• saturated: all single bonds between
carbons, full of H
– usually solid at room temperature
• unsaturated: at least one double bond
between Cs, not full of H (bends in
chain) monounsaturated or
polyunsaturated
– usually liquid at room temperature
Lipid Test
• Reagent—brown paper
• Positive test—greasy spot translucent
• Negative test—dries normally
Macromolecule #3
• Proteins
– largest group
– contains C, H, O, N (S)
– Often end in -in
– monomers of proteins are amino acids and
are bonded together by peptide bonds
– made from combinations of 20 amino acids
– Used in structural material, enzymes, cell
transport, cell structure, & antibodies
– Examples: keratin (hair & skin), albumin (egg whites),
Hemoglobin (carries O2 in blood), Myosin (muscle)
Proteins
• All enzymes are special proteins and are vital
to all living organisms
• Proteins are sensitive to temperature and pH
and if exposed to these they can permanently
change shape and not work
– Denature: the permanently changing shape of a
protein causing it not to work
•
•
•
•
amino + amino=peptide bond
2 amino acids =dipeptide
many amino acids=polypeptide
proteins can have more than one polypeptide
chain
Proteins
amino
acids
Protein Food Test
• Reagent—Biuret’s solution
• Positive test—goes from
pale blue to light purple
or pinkish in the presence
of protein
• Negative test—
any other than
the above
Enzymes
• Often end in –ase and can be named
for what they work on “substrate”
• For example- sucrase breaks down
sucrose
• Work by speeding up reactions by
lowering the energy of activation
– Activation energy: minimum amount of
energy required to start a chemical rxn
• All living organisms NEED enzymes!
Enzyme vocabulary
• Enzymes are specific and reusable!
• Substrate= what the enzymes work
on
• Reusable=are used over and over
again
• Specific=only work on one substrate
How enzymes work:
• Enzymes act on substrates at an active
site (imagine a flexible lock and key).
• Coenzymes are enzyme helpers.
Reaction pathway
without enzyme
Activation energy
without enzyme
Activation
energy
with enzyme
Reactants
Reaction pathway
with enzyme
Products
Macromolecule #4
• Nucleic Acids
– Contains C, H, O, N, P (phosphorous)
– The monomers are nucleotides
– Nucleotide structure: 1 pentose sugar
(either ribose or deoxyribose), 1
phosphate, and 1 nitrogen base
Monomer of Nucleic Acids
• Nucleotide
Macromolecule #4
• Nucleic Acids
– Examples: Both found in the cell
• DNA (deoxyribonucleic acid)genetic code ->heredity
information in the nucleus of
eukaryotic cells or center of
prokaryotic cells
• RNA (ribonucleic acid)-carries
out genetic code of DNA, found
throughout the all cells
Nitrogen bases
• In DNAAdenine, thymine,
cytosine & guanine
• In RNA
Adenine, uracil,
cytosine & guanine
DNA
RNA
Name These Tests/Reagents
Recap
ORGANIC
Compounds
include
Carbohydrates
Lipids
Proteins
Nucleic
acids
that consist of
that consist of
that consist of
that consist of
Monosaccharide
Fatty acids &
glycerol
Amino acids
Nucleotides
which contain
which contain
which contain
which contain
CHON
CHONP
CHO
CHO