Transcript Biomolecules Honors 15-16

Organic
Chemistry within
Biology
Image: Michael Ströck
“Macromolecules”
• Macro
– BIG
• Molecule
– More than one atom
covalently bonded
together
What makes macromolecules
different?
•
•
•
•
•
Size
Shape
Components (types of elements)
Part of your diet (connect to food groups)
Functional groups
Which other elements are
essential to living things?
• CHONPS
– Carbon
– Hydrogen
– Oxygen
– Nitrogen
– Phosphorous
– Sulfur
Unity - All Macromolecules form
Monomers and Polymers
• Monomer
– Single subunit of a
macromolecule
Glucose
• Polymer
– Macromolecule made
of repeating subunits
How do you make a polymer?
Dehydration Synthesis
• To build polymers
• Lose a water
molecule
Dehydration Synthesis of
Maltose
How do you break down a
polymer?
Hydrolysis
• To break down
• Requires a water
molecule
Functional Groups: Structures that give
properties to a molecule
Hydroxyl
-OH
Alcohol
Polar, form
H-bonds
Carboxyl
-COOH
Acidic
Amino
-NH2
Organic
Acids, amino
acids
Amino acids
Sulfhydryl
-SH
Proteins
Form sulfide
Bonds
Phosphate
-PO4
DNA, ATP
Store energy
Basic
Find the functional groups!
• Can sugar dissolve in
water?
• ATP…what might be
the function of this
molecule?
Two more…
• More than one
functional group?!?
• What gives this
molecule its twist?
?
Inorganic vs Organic Molecules
?
• Inorganic Molecules >
Molecules that don’t have
Carbon Hydrogen (C-H) bonds.
• The major organic molecules
(molecules with carbon-hydrogen
bonds) found in living things
are:
1. carbohydrates
2. proteins
3. lipids
4. nucleic acids
Image:
Methane : DynaBlast Wiki
Amazing Carbon
Carbon is unique in many ways:
The atoms can bond with each other to form long
chains.
Sometimes the ends of these chains join together
to form a ring.
C has 4 available sites for bonding in its valence
shell, so it can form 4 single bonds.
Double bonds form when two atoms share two
pairs of electrons (two covalent bonds).
Images :www.phy.cuhk.edu.hk/.../laser/laser_e.html
Which molecules are organic?
C
Ne
C2H7O2N
NaCl
CO2
MgCl2
C6H12O6
Organic Molecules - Carbohydrates
• “carbon hydrates”
• One carbon molecule to one
water molecule (CH20)n.
• Saccharide is a synonym for
carbohydrate.
• The prefixes on the word
“saccharide” relates to the
size of the molecule (mono-,
di-, tri- poly-).
Elements in the molecule!
Organic Molecules - Carbohydrates
Monosaccharides
•
•
•
single sugars (one molecule)
simplest
*glucose, fructose
Disaccharides
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•
•
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double sugars
combination of two monosaccharides
* sucrose = glucose + fructose
* lactose = glucose + galactose
Polysaccharides
•
•
•
polymers composed of several sugars
can be same monomer (many of same monosaccharide) or mixture of
monomers
Storage carbohydrates: glycogen (animals) starch (plants)
•
structural carbs: chitin (animals), cellulose (plants)
Structural Formulas
Glucose
Fructose
Galactose
Functional Groups:
Definition: groups of elements that give
molecules special properties
Hydroxyl
R-OH
O
Carbonyl
R-C
O
H
R-C-R
Organic Molecules - Proteins
Complex organic macromolecules fundamental to living cells.
Composed of one or more chains of amino acids.
Proteins perform many functions in cells, including:
1. Structure
• Components in cell walls, membranes, and within cells themselves.
2. Catalysts
• Chemicals that speed up, or increase the likelihood of a chemical
reaction.
• The catalysts in cells are called enzymes.
3. Regulation
• Some regulate cell function by stimulating or hindering either the
action of other proteins or the expression of genes.
4. Transportation
• Some act as channels and “pumps” that move substances into or out
of cells.
5. Defense
• Antibodies = proteins that defend your body against microorganisms
• Some bacteria produce proteins (bacteriocins) that kill other bacteria.
Images:
Enzyme: www.chemistry.wustl.edu/.../DrugStrategies.html
Protein Channel: library.thinkquest.org/27819/ch3_2.shtml
AntibodyAntigen: US Gov, pub dom
Elements Found in Protein
Definition: groups of elements that give
molecules special properties
– Sulfur
– Oxygen
– Nitrogen
– Carbon
– Hydrogen
4/11/2017
S
O
N
C
H
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Functional Groups of Basic
Amino Acid
• Definition: groups of elements that give
molecules special properties
• Amino
-NH2
• Carboxyl
-COOH
Many Kinds of Amino Acids
Small Polymers = Dipeptide
4/11/2017
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Monomer
• The basic unit of a protein is an amino acid
4/11/2017
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Amino Acid Structure
• The “R” in the structure is a variable that
can be replaced by different elements to
create different types of protein.
4/11/2017
http://www2.glos.ac.uk/gdn/origins/images/amino.gif
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Organic Molecules - Proteins
Amino Acids
Proteins are polymers composed of
monomers called amino acids.
Amino acids contain a
1. base amino group ( -NH2)
2. acidic carboxyl group ( -COOH)
3. hydrogen atom
…all attached to same carbon atom (the α –
carbon…alpha carbon).
Fourth bond attaches α-carbon to a side group
(--R) that varies among different amino
acids.
There are hundreds, but most organisms use only 21
amino acids to build proteins.
Side groups important … affects the way a proteins
amino acids interact with one another, and how a
protein interacts with other molecules.
Image: www.rothamsted.ac.uk/.../courses/guide/aa.htm
Organic Molecules - Proteins
Peptide Bonds:
Link amino acids together in
chains, like the beads on a
necklace.
Peptide bonds connecting amino
acids are: ionic? covalent?
A dipeptide is 2 amino acids
linked together.
A polypeptide, more than two.
Image: homepages.ius.edu/GKIRCHNE/biomolec.htm
Organic Molecules – Protein Structure
Every protein has at least three levels of structure, and some four.
.
Image: www.answers.com/topic/rosetta-home
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Hydrophobic…insoluble in water.
Not attracted to water because …
non-polar covalent bonds linking carbon & hydrogen aren’t attracted to the
polar bonds of water.
Images:
Phospholipid bilayer, BensAccountWiki
BeeWithHoneycomb : www.agr.state.il.us/.../bee_with_honeycomb.jpg
What Elements are in a Lipid?
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•
•
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Carbon
Hydrogen
Oxygen
Phosphorus
Monomers in a Lipid
 Glycerol
• polar; soluble in water
• Contains –OH groups
 Fatty Acids
• saturated and
unsaturated
• Hydrocarbon chain
Polymer
Triglycerides = 3 fatty acids + 1 glycerol
Functional Groups
• -OH (hydroxyl)
• -COOH (carboxyl)
Where Are Lipids Found?
• Phospholipids
• Steroids
 Plasma membrane
 Cholesterol and
sex hormones
• Waxes
• Fats
 Ear wax
 Under Skin
Types of Fatty Acids
 Saturated
 No double bonds
 Has as many
hydrogen as it can
hold
 Liquid Fat (oils)
 Unsaturated
 Has double bonds
 Each carbon has
less than two
hydrogen atoms
 Solid fats (butter)
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Fats
Fats and oils are made
from two kinds of
molecules:
• Glycerol
(a type of alcohol)
• Fatty acids
(triglycerides)
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Saturated fats
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•
Mostly from animal sources
•
Single bonds between the carbons in
their fatty acid tails (all carbons are
bonded to max number of hydrogens
possible).
Hydrocarbon chains fairly straight and
packed closely together … so solid at
room temperature.
Unsaturated fats (oils)
•
Mostly from plant sources
•
Have double bonds between some
carbons in the hydrocarbon tail, causing
bends or “kinks” in shape.
•
Kinks in hydrocarbon tails, so
unsaturated fats can’t pack closely
together … liquid at room temp.
Image:
biology.clc.uc.edu/Courses/bio104/lipids.htm
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Phospholipids
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Hydrocarbon tails Hydrophobic,
but phosphate group end are
Hydrophilic.
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So phospholipids are soluble in
both water and oil.
•
Tails from both layers facing
inward and the heads facing
outward = phospholipid bilayer.
Images:
Phospholipid Bilayer: BensAccount Wiki
CellMembrane: NIST Center for Neutron Research
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Waxes
•
Do not have a
hydrophilic head: so
completely water
insoluble.
•
Certain
microorganisms, such
as Mycobacterium
tuberculosis, are
surrounded by a waxy
wall.
What advantage would this
give the bacteria?
Mycobacterium
tuberculosis
Image: M. Tuberculosis CDC
Organic Molecules – Lipids
(Fats, Phospholipids, Waxes & Steroids)
Steroids
•
The central core of a cholesterol
molecule (4 fused rings) is shared
by all steroids,
•
Cholesterol is precursor to our
sex hormones and Vitamin D.
•
Our cell membranes contain
cholesterol (in between the
phospholipids) to help keep
membrane “fluid” even when
exposed to cooler temperatures.
Images:
Lansterol : Mysid Wiki
Lipid Bylayer Cholesterol: cellbio.utmb.edu/cellbio/membrane_intro.htm