Transcript Section 2.3 Carbon Compounds Power point

2.3 Carbon-Based Molecules
KEY CONCEPT
Carbon-based molecules (proteins, lipids,
carbohydrates and nucleic acids) are found in all
organisms. These molecules form the structures
and carry out the functions in all living organisms.
Why is Carbon so special?
• Carbon has four valence electrons.
• It .shares these electrons with other atoms
to form molecules that are held together by
strong covalent bonds.
2.3 Carbon-Based Molecules
Molecules that contain carbon are called
Organic compounds.
There are over 2 million known organic
compounds.
They are made and found only in living
things.
3 basic shapes of carbon-based compounds
• straight chain
• branched chain
• ring
2.3 Carbon-Based Molecules
Monomers
and
Polymers
Large carbon-based molecules are
made of many repeating small
subunits joined by chemical bonds.
The smaller molecules are called Monomers
Ex. Glucose
Larger molecules formed by joining
monomrers are called Polymers.
Polymers can be made of the same repeating molecule
2.3 Carbon-Based Molecules
OR, polymers can be made by combining different
monomers
2.3 Carbon-Based Molecules
=MONOMER – one train car
=POLYMER – the whole train
The reaction that joins monomers to form
polymers is called Dehydration Synthesis.
• Animation
Dehydration synthesis means “to make by removing water.”
(Dehydration – remove water
Synthesis – to make)
Dehydration Synthesis
• Polymers can be broken down into the monomers
through Hydrolysis
• Hydrolysis means “to break by adding water”
• Dehydration synthesis – builds bigger molecules
• Hydrolysis – breaks down bigger molecules
• They are opposite reactions!
2.3 Carbon-Based Molecules
Four major groups of organic compounds
in living things:
•
•
•
•
Carbohydrates
Lipids
Proteins
Nucleic Acids
2.3 Carbon-Based Molecules
Quick Check for Understanding –
What atom do all these molecules contain?
2.3 Carbon-Based Molecules
Quick Check for Understanding –
What atom do all these molecules contain?
CARBON
2.3 Carbon-Based Molecules
Where do we get these molecules?
(Click for video)
FROM OUR FOOD!!
2.3 Carbon-Based Molecules
CARBOHYDRATES
Types of Atoms in Carbohydrate molecules:
Carbon (C), Hydrogen (H), and Oxygen (O)
• Foods that contain primarily carbohydrate
molecules are called Sugars and Starches
Uses in Living Things
1. “Quick” Energy
2. Builds body structures
3 Categories of Carbohydrates based on Size:
1. Monosaccharides
(smallest)
Monomers
2. Disaccharides
3. Polysaccharides
(largest)
Polymers
1. Monosaccharide: one single molecule
1. Glucose – made in photosynthesis;
blood sugar
glucose
2. Galactose - Component of milk sugar
3. Fructose - fruit sugar
4. Deoxyribose and Ribose – in nucleic acids
DNA and RNA
2. Disaccharide – 2 monosaccharides joined together
1. Sucrose – table sugar (glucose + fructose)
2. Lactose – milk sugar (glucose + galactose)
glucose
fructose
3. Polysaccharides - many monosaccharides joined
together
1. Starch – glucose storage in plants (bread, taters)
2. Glycogen – glucose storage in animals
3. Cellulose – forms plant cell walls
4. Chitin – forms insect exoskeletons and
fungus cell walls
glucose
glucose
glucose
glucose
cellulose
glucose
glucose
glucose
glucose
2.3 Carbon-Based Molecules
Carbohydrate molecules can have the same
monomers but be joined together differently
.
Polymer (starch)
Starch is a polymer of
glucose monomers that
often has a branched
structure.
Polymer (cellulose)
monomer
Cellulose is a polymer
of glucose monomers
that has a straight, rigid
structure
Ex.s of different monomer arrangements
Chitin – forms rigid insect bodies
•
Polymer
Monomer
• REMEMBER A UNIFYING THEME:
• The structure of a molecule affects
its function
2.3 Carbon-Based Molecules
LIPIDS
(Fats, Oils, Waxes)
• Types of Atoms: C, H, O
Uses of Lipids in Living Things:
1. Stores large amounts of chemical energy
2. Provide warmth and insulation
3. #1 component of cell membranes
4. Make hormones the body’s chemical
messengers
Common Features of Lipids
1. Nonpolar molecules – no charge on atoms
2. Hydrophobic – Can’t dissolve in water
3. Many lipids contain fatty acid molecules.
• Fatty acid molecules share same basic
structure
3 Categories of Fatty Acids
No double bonds
between Carbon atoms
No kinks
One or more double
bonds between
carbon atoms
Molecule has kinks
and bends
If the Fatty Acid molecules have :
• Single bonds between C atoms –
Saturated Fats (Bad fats in diet)
• Double bonds between C atoms –
Unsaturated Fats (Good fats in diet)
Blood Cholesterol Count
• LDL - Lousy for you Want # to be LOW
• HDL - Happy for you Want # to be HIGH
• Dangers of Saturated Fats (Video)
Get in the habit of checking food labels for fat content
Categories of Lipids and their Functions:
1. Triglycerides - Provide Energy
Categories of Lipids and their Functions:
2. Phospholipids – make cell membranes
2.3 Carbon-Based Molecules
Has negative charge
Molecules have no charge
3. Sterols/Steroids – make hormones
4. Waxes – protective coating on
skin and leaves (leaf cuticle) to
prevent water loss
2.3 Carbon-Based Molecules
Types of Atoms in Protein Molecules:
C, H, O, N, S
Uses of Proteins in Organisms:
• Enzymes – Speed up chemical
reaction times
• Transport molecules through cells
• Antibodies in immune system
Workhorses of the cell!
Monomers of Proteins: Amino Acids
• 20 different amino acid molecules
• 9 amino acids are Essential – Can only be
obtained by eating food
Basic structure of all 20 amino acids
Variable group
Amine group
Carboxylic acid
group
2.3 Carbon-Based Molecules
• Amino acids are joined by peptide bonds
which form between them through
dehydration synthesis
.
OH + H
OH + H
• The sequence,
or order, of
amino acids is
called the
“primary
structure” – this
is what
determines a
protein’s
structure and
function
Amino Acids – Monomer
Protein – Polymer
Ex.s of Protein Molecules in Organisms
• 1. Albumin – protein in egg white
• 2. Amylase – breaks apart starch to glucose
through hydrolysis. Enzyme found in your saliva
• 3. Keratin – protein in hair, feathers and nails
• 4. Hemoglobin – in red blood cells, oxygen
attaches to it to be carried throughout the body
and delivered to all cells
2.3 Carbon-Based Molecules
NUCLEIC ACIDS
DNA and RNA
2.3 Carbon-Based Molecules
Types of Atoms in N.A.:
C, H, O, N, P
Two Types of Nucleic Acid Molecules
1. Deoxyribonucleic Acid - DNA
2. Ribonucleic Acid – RNA
Uses of Nucleic Acids
1. Stores hereditary
information needed to
make protein molecules by
the cell
Monomers of Nucleic Acids
1. Nucleotides – made of 3 molecules
joined together
2. 1000’s of nucleotides join together to make
DNA/RNA.
3 Molecules Join to form a Nucleotide
1. Sugar
2. Phosphate group
3. Nitrogen containing base (5 kinds).
A phosphate group
deoxyribose (sugar)
nitrogen-containing molecule,
called a base
2.3 Carbon-Based Molecules
Types of Nitrogen Containing Bases in:
RNA
DNA
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•
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Adenine
Thymine
Guanine
Cytosine
A
T
G
C
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Adenine A
Uracil U
Guanine G
Cytosine C
• In Summary:
• The majority of molecules in living things are
either:
• Inorganic – ex. Water
• OR
• Organic – ex. Carbohydrates, Lipids, Proteins,
Nucleic Acids
• The chemical basis of life is a Unifying Theme
for all organisms