Transcript Amino acids - Aurora City Schools

1. The important Characteristics of
Carbon
 Forms 4 covalent bonds
 Forms double and triple bonds
 Forms long chains and rings
 Can bind with many other elements
 Even electron distribution (nonpolar molecules)
 Isomers – molecules that have the same formula but
different structures.
2. Macromolecules, Monomers
and Polymers
(Hint: think of the meaning of the prefixes)
What do these words mean?
Polygons
Polyester
Polygamy
2. Macromolecules, Monomers
and Polymers
 Polymer – Smaller organic molecules join into long
chains.
 Monomer – the individual unit that builds up
polymers
 Macromolecules – Very large molecules
3. Dehydration synthesis and
Hydrolysis
 These two terms refer to the processes that forms
monomers and polymers.
 Dehydration synthesis – A reaction that removes
molecules of water to form polymers from monomers
(http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html or
http://www.youtube.com/watch?v=UyDnnD3fMaU )
 Hydrolysis – The reaction that adds water to polymers
to separate them to their individual monomers.
4. What are the big four?
Three out of the 4 types of
biochemical macromolecules
can be found on food
nutrition labels…
Look at the label to the left. 3
of the 4 macromolecules can
be found in foods.
1____________________
(0 grams in this product)
(13 grams in this product)
2____________________
(9 grams in this product)
3____________________
4. What are the big four?
 Fats (we call them lipids)
 Carbohydrates
 Proteins
 Nucleic acids (DNA and RNA)
When studying these
biochemical molecules, we are
interested in finding out…..
 what they do for living things.
 what they generally look like.
 what their monomers are.
 and how they may help the body gain energy to
sustain life.
SO, LETS GET STARTED!
5. Carbohydrates
 Molecules that form from atoms in 1C:2H:1O ratio
 Monomers: Monosaccharides (simple sugars)
 Monosaccharides are usually sweet, white powdery
substances (such as fructose, glucose) that form rings
of carbon atoms.
 Monosaccharides in general serve as direct, quick
sources of energy for living organisms during cellular
respiration, they are building blocks of many polymers
 Important monosaccharides:
 Glucose
 Fructose
 Disaccharides – two monosaccharide molecules
combine by dehydration synthesis to form
disaccharides
 Important disaccharides:
 Lactose – found in milk sugar
 Succrose – table sugar
 Polysaccharides – many (tens to hundreds) units of
monosaccharides combine by dehydration synthesis
 Polysaccharides also separate to monosaccharides by
hydrolysis while taking in water.
Important polysaccharides:
 Starch – made up of many glucose units, it is an important
storage polysaccharide that is found in plant roots and
other tissues. It stores monosaccharides that can be
broken down later to release useful energy during cellular
respiration – ONLY IN PLANTS
 Glycogen – also made up of many glucose units, it is an
important storage polysaccharide in the liver and animal
muscles. It can also be broken down to monomers to
release energy during cellular respiration. ONLY IN
ANIMALS
 Cellulose – also made up of many glucose units. However,
in this case the molecule is not easily broken down to its
monomers. It is important for providing a rigid structure
in plant cell walls.
 Chitin – made up of some nitrogen containing
monosaccharides. It is an important polysaccharide
that provide the solid structure of arthropods and
fungi.
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http://biomodel.uah.es/en/model3/index.htm
6. Lipids
 a diverse group of molecules that are nonpolar and
generally do not dissolve in water
 They mostly contain carbon, hydrogen, very few
oxygen atoms, but some also have phosphorous.
 There are three distinct groups of lipids:
 Simple lipids
 Phospholipids
 Sterols
6A. Simple Lipids
 Very large molecules that form from 2 different kinds
of monomers by dehydration synthesis:
 3 Fatty acids – are long chains of carbon with oxygen at
the end (can be saturated and unsaturated)
 1 Glycerol – smaller 3-carbon compound.
 Simple lipids are important as storage materials in all
living things. They can store twice as many calories as
polysaccharides can. Oils (mostly from plants)
contain more unsaturated fatty acids, while fats
(animals) contain more saturated fatty acids.
 Simple lipids also dissolve vitamins

http://biomodel.uah.es/en/model3/index.htm
6B. Phospholipids
 Phospholipids – phosphate containing lipids.
 Their monomers: 1 glycerol + 2 fatty acids (saturated
or unsaturated) + phosphate. These monomers
combine by dehydration synthesis
 Phospholipids have both polar and nonpolar sections.
As a result, they are able to dissolve in both type of
solvents as well.
 They are important for living things because they form
the borders of all cells (cell membranes) and also
participate in forming many cell organelles.
6C. STEROLS
 Sterols are a highly nonpolar (hydrophobic) group of
molecules. They are formed from four rings of carbon
atoms. One ring is made up of five carbons, the other
three rings are made up of 6 carbons.
What are steroids used for?
But some steroids are necessary
in certain concentrations.
 Cholesterol – important component of the cell
membrane, but can be harmful if overdosed in diet.
Too much cholesterol can lead to atherosclerosis and
other circulatory problems.
 Sex hormones – responsible for normal development,
sexual function, muscle and body hair formation
 Vitamin D – important vitamin for normal bone
formation, immune functions
 Help to digest fats.
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http://biomodel.uah.es/en/model3/index.htm
7.Proteins
 Monomers: Amino acids – they are small molecules
but complex themselves.
 Components of amino acids:
 Carboxyl group – COOH
 Amino group – NH2
 Side chain (labelled R)
 The R group can be 20 different kinds of side chains.
Because of these side chains we have 20 different types
of amino acids in our body.
 The R group determines the characteristics of the
amino acid
 Some amino acids are essential (our body cannot
make these, so we need to take these in with our food)
while others are nonessential (we can make these)
7B. Combining Amino Acids
 Two amino acids can combine at their amino and
carboxyl ends by dehydration synthesis. They form a
peptide bond together.
 The product of this reaction is a dipeptide (2 amino
acids), polypeptide (many amino acids)
 http://www.johnkyrk.com/aminoacid.html
7C. Protein Structure
 Once the proper number of amino acids combine by
peptide bond, we get a polypeptide chain – this is the
primary structure of a protein (the number and types
of amino acids combined to form a protein)
 Secondary structure – The long polypeptide chain
folds up by using H-bonds.
 Alpha helix – If the H-bonds form within the
polypeptide chain, a spiral staircase shape is formed.
 Beta pleaded sheet – If the H-bonds form between
longer stretches of polypeptide chains a long fan shape
is formed.
 Tertiary structure – all kinds of chemical bonds
(covalent, ionic, disulfide bridge, H-bond, van der
Waals attraction, dipole-dipole interactions) are used
to form the 3 dimensional structure of the polypeptide
chain.
 If the protein is made up of only one polypeptide
chain, than this is the final structural level of the
protein
 Quaternary structure – If a protein is made up of
more than one polypeptide chains, they are connected
by various bonds during the quaternary structure of
the protein.
 http://www.johnkyrk.com/aminoacid.html
 http://www.youtube.com/watch?v=lijQ3a8yUYQ
7D. Protein Function
 Enzymes – catalyze reactions in the body
 Structural proteins – support various structures (cocoon,
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hair, horns feathers, spider silk)
Storage proteins – proteins in milk, eggs, seeds
Transport proteins – like hemoglobin, carry molecules
Hormones – regulate growth, development, metabolism
Receptors – detect signals from the environment
Motor proteins – like muscle, move organisms or
substances inside
Defensive proteins – antibodies that fight against bacteria
and viruses
http://www.youtube.com/watch?v=yz4lFeqJPdU&feature=related
Prions: http://learn.genetics.utah.edu/content/begin/dna/prions/
8A. Nucleic Acids – Their
Monomers
 Macromolecules with complex monomers called
nucleotides
 Nucleotides are formed from three smaller
components:
 Monosaccharide with 5 carbon atoms – ribose or
deoxyribose
 Phosphate ion (PO43 N-containing bases (Adenine (A), guanine (G), cytosine
(C) and thymine (T)
 The function of nucleotides is to build up nucleic
acids, but they can also act as energy and hydrogen
carrying molecules in different biological processes.
8B. DNA (Deoxyribonucleic Acid)
 One polymer of nucleotides is DNA that is formed by
dehydration synthesis.
 DNA has two polynucleotide chains combined with Hbonds at the base section of the nucleotide. The
nucleotides that form the H-bond follow the base
pairing rule: Adenine binds with thymine (A = T) and
guanine binds with cytosine (G = C)
 The rest of the nucleotides form the sugar-phosphate
backbone
 The sugar is always deoxyribose in DNA
 http://learn.genetics.utah.edu/content/begin/dna/
 DNA is used by all living cells as a storage molecule of
their genetic information. DNA is able to copy itself
and pass on the genetic material when a cell
reproduces.
8D. Ribonucleic Acid
 One polynucleotide chain, formed by dehydration
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synthesis from nucleotides.
The bases include adenine, guanine, cytosine and
uracil
The sugar is ribose
RNA forms only a single chain of many nucleotides
Its function is to carry small segments of genetic
information in the cell
The nucleic acids in food are not
considered a substance that the
body uses to gain energy.
So, you won’t find
nucleic acids listed on a
nutrition label!