Download CARBOHYDRATES

Section 2.3 Carbon-based Molecules
Key Concept: Carbon-based molecules are the basis of life
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Carbon atoms are the “building blocks of life” because they :
1. Are the basis of most molecules in living things (Structure)
2. Carry out processes that keep organisms alive (Function)
Molecules that contain carbon are called organic compounds.
There are over 2 million known organic compounds.
Why is Carbon so special?
Carbon atoms have four valence electrons that they use to
form strong covalent bonds with up to four other atoms.
Monomers and Polymers
Many carbon-based molecules are made of many small
subunits bonded together.
Smaller individual molecules are called monomers.
Larger molecules made when monomers bond are called
polymers.
Dehydrations synthesis is the reaction that causes monomers to
join together to make polymers.
Dehydration synthesis means “making by removing water.”
A polymer can be formed by joining all the same type of
monomers or different types.
Polymers can be broken down into the monomers that made
them through hydrolysis.
Hydrolysis means to “break by adding water.”
Four Groups of Organic Compounds Found in Living Things
1.
Carbohydrates
2.
Lipids
3.
Proteins
4. Nucleic Acids
CARBOHYDRATES
Types of atoms: C, H, O
Foods that contain primarily carbohydrate molecules are
called Sugars, Starches
Uses in living things:
1. Store energy
2. Provide structure
Categories of Carbohydrates by Molecule Size:
1. Monosaccharides – single molecule (CH2O)n(3-8)
1. Glucose – made when plants photosynthesize
2. Galactose – component of milk sugar
3. Fructose – fruit sugar
2. Disaccharides – 2 monosaccharides joined together
1. Sucrose – table sugar (glucose + fructose)
2. Lactose – milk sugar (glucose + galactose)
3. Polysaccharides – many monosaccharides joined together
1. Starch – glucose storage in plants
2. Glycogen – glucose storage in animals
3. Cellulose – used to build plant cell walls
4. Chitin – used to built hard shells in animals
LIPIDS
Types of Atoms: C, H, O
Uses of Lipids in Living Things:
1. Source of usable energy
2. Provide warmth and insulation
3. Part of cell membranes
4. Makes hormones
Common Features of Lipids:
1. Nonpolar
2. Hydrophobic = Don’t dissolve in water Water hater
3. There isn’t a specific monomer found in all Lipids.
Many lipids do contain fatty acids.
If the Fatty acid molecules have :
Single bonds between C atoms – Saturated fats
Double bonds between C atoms – Unsaturated fats (Healthy food)
Categories of Lipids:
1.
Triglycerides – Provides Energy
Fats - Solid at room temperature
Oils - Liquids at room temperature
2. Phospholipids – Makes Cell membranes
3.
Sterols (ex. Cholesterol) – Makes Sex hormones
4. Waxes – Protective coating on skin and leaves
Structure of Triglycerides
1. Glycerol molecule
2. 3 Fatty acid molecules
Structure of Phospholipids
1. Phosphate molecule
2. Glycerol molecule
3. 2 Fatty acid molecules
PROTEINS
Types of Atoms: C, H, O, N, S
Uses of Proteins in Living Things:
1.Make chemical reactions go faster (enzymes)
2.Move molecules in/out cells
3.Help cells move
4.Molecule receptors on cell surfaces
Monomers of Proteins:
1. 20 different Amino Acids which can be linked by Peptide bonds
The specific sequence of amino acids determines a protein’s
structure and function ex. Hemoglobin p.48
Examples of Protein molecules:
1.Albumin – protein in egg white
2.Amylase –breaks apart starch molecules to glucose
3.Keratin – protein in hair, feathers and nails
4.Hemoglobin – protein in blood that O2 attaches to
Nucleic Acids
Types of Atoms: 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 (DNA)
2. Helps to make protein molecules (RNA)
Monomers of Nucleic Acids
1. Nucleotide – complete unit made of 3 molecules
2. 1000’s of nucleotides join together to make a n.a.
3 Molecules in a Nucleotide:
DNA
Sugar – deoxyribose
Phosphate PO4
Nitrogen containing base
RNA
Sugar – ribose
Phosphate PO4
Nitrogen containing base