Download Chap 2 Macromolecule

Macromolecules of Life
(Read Ch 2, pp. 22-26)
Macromolecules of Life?
 There are four major macromolecules of life. They are…?
1.
2.
3.
4.
Carbohydrates
Proteins
Lipids
DNA/RNA
Organic Molecular Structure of Living Systems
1. Carbohydrates
•
•
•
Composed of C, H, and O usually in the ratio
of 1 C: 2 H: 1 O.
Functions:
 Structural Elements
 Energy Source
Examples:



Monosaccharides
Disaccharides
Polysaccharides
Organic Molecular Structure of Living Systems
1. Carbohydrates

Foods high in…



Pasta
Cereals
Bread


Glucose=
6 carbon sugar
Organic Molecular Structure of Living Systems
Monosaccharides
 Simple sugars
Ex: Glucose – 6 carbon sugar
Fructose
Galactose
Glucose
Chemical
Formula:
C6H12O6
Organic Molecular Structure of Living Systems
Disaccharides
 Two simple sugars joined together.
 Examples:
Maltose (malt sugar) = glucose + glucose
Sucrose (table sugar) = glucose + fructose
Lactose (milk sugar) = glucose + galactose
Organic Molecular Structure of Living Systems
Polysaccharides
– Many simple sugars joined together forming long chains
called polymers.
Glycogen: Storage form of glucose in animals.
Starch:
Storage form of glucose in plants.
Important food for animals.
Cellulose: Structural element of plants.
Chitin:
Structural element in the
exoskeletons of arthropods.
Organic Molecular Structure of Living Systems
2.Lipids
 Elements: C, H, O and some with P
 Function: storage of energy, food source in animals
 Examples:
1. Neutral Fats
2. Phospholipids
3. Steroids
 Foods high in…
 Icecream, butter, dairy products
Organic Molecular Structure of Living Systems
Phospholipids are…
 Amphiphilic compounds are polar and water –soluble
on one end and nonpolar on the other end also
 They have a tendency to assemble themselves into semipermeable membranes
Organic Molecular Structure of Living Systems
– Saturated Fatty Acids
• Every carbon in the chain holds two hydrogen
atoms.
• More common in animals than plants
• Usually solid at room temperature
• Unhealthy
– Unsaturated Fatty Acids
• Have 2 or more carbon atoms joined by double
bonds
• Typical of plant oils
• Usually liquid at room temperature (68-77
degrees)
• Healthy
Organic Molecular Structure of Living Systems
Phospholipids
• Important components of molecular
organization of tissues, especially membranes
– Phosphate group is charged and polar.
Organic Molecular Structure of Living Systems
Steroids
 Complex alcohols
 Structurally unlike fats but have fat-like properties –
polar and non-polar parts
 Examples:
 Vitamin D
 Cholesterol
 Sex Hormones
Organic Molecular Structure of Living Systems
• 3. Nucleic Acids
• Elements: phosphate group,
sugar, base
• Complex molecules
• nucleotides
– Nucleotide:
• Deoxyribose sugar
• Phosphate group
• Nitrogenous base
• Examples (types) of nucleic acids?
 DNA (deoxyribonucleic acid)
 RNA (ribonucleic acid)
Organic Molecular Structure of Living Systems

Nucleic Acids

What are the bases in DNA?




Thymine
Adenine
Cytosine
Guanine
Organic Molecular Structure of Living Systems
Nucleic Acids
• What are the bases in RNA?




Uracil
Adenine
Cytosine
Guanine
• Do you remember which base
bonds to another?
RNA
A=U
C=G
DNA
A=T
C=G
Organic Molecular Structure of Living Systems
4. Proteins
• Elements: N, H, O, C, R group
• Large, complex molecules composed of 20
kinds of amino acids
Organic Molecular Structure of Living Systems
4. Proteins
Functions: structure, enzymes, hormones
Ex: primary, secondary, tertiary, quaternary (hemoglobin)
Foods high in…meat, fish
Organic Molecular Structure of Living Systems
4. Proteins
• Amino acids are linked by peptide bonds to form
long, chainlike polymers
Dehydration
synthesis reaction
Organic Molecular Structure of Living Systems

Four levels of protein organization
1. Primary Structure

Linear sequence of amino acids composing a
polypeptide chain
2. Secondary Structure

Spiraling or pleating of the
primary structure
 Stabilized by hydrogen bonds
 Ex: Alpha helix, beta pleated
sheets
Organic Molecular Structure of Living Systems
3. Tertiary Structure


Bending and folding of the secondary structure produced this
complex, stable structure
Structure stabilized by:
 Disulfide bonds
 Hydrogen bonds
 Ionic bonds
beta sheet
spiral
 Hydrophobic bonds
Organic Molecular Structure of Living Systems
4. Quaternary Structure
• Proteins that contain more than
one polypeptide chain
Function of Proteins:
– Structural components of
cells (Collagen)
– Catalyze chemical reactions
(Enzymes)