ORGANIC MOLECULES
Lipids and Carbohydrates
Organic Macromolecules
• Large, complex molecules made of chains
of smaller molecules
• Four main types of macromolecules:
• Carbohydrates
• Lipids
• Nucleic Acids
• Proteins
Building Macromolecules
• The small building blocks of macromolecules are called
monomers
• Monomers linked together by covalent bonds are called
polymers
Making and Breaking Macromolecules
• Dehydration Synthesis
• Joins two monomer molecules together
• Water is released
• Hydrolysis
• Breaks polymers down into monomers
• Water is used to break the bonds
Dehydration Synthesis and Hydrolysis
• https://www.youtube.com/watch?v=ZMTeqZLXBSo
Carbohydrates
• Made of Carbon (C), Hydrogen (H), and Oxygen (O)
atoms in a 1:2:1 ratio
• C6H12O6 = glucose
• C5H10O5 = ribose
Carbohydrate Structure
• Simple sugars are monosaccharides (glucose) or
disaccharides (sucrose)
• Polysaccharides (starch) are polymers made of many
monomers
Carbohydrates
• Examples:
• Monosaccharides (One sugar- glucose, fructose)
• Disaccharides (two sugars – sucrose)
• Polysaccharides (many sugars- cellulose, starch, glycogen)
• Functions:
• Cellular respiration – glucose is the energy source used to make ATP
• Energy storage – glycogen and starch are used for short-term storage
• Structure- plant walls are made of cellulose, insect exoskeletons
made of chitin
Lipids
• Contains Hydrogen, Carbon, and Oxygen
• Almost all Hydrogen (H) and Carbon (C) atoms
• Very few Oxygen (O) atoms
Lipids Structure
• Fatty Acid “tails” connected to a glycerol molecule
• NOT a true polymer
Lipids
• Examples:
• Fats, oils, waxes, sterols (hormones)
• Functions (jobs):
• Energy storage - long-term “fat” storage in the body
• Insulation & protection – fats help to insulate, waxes coat and protect
• Chemical messengers – hormones act as chemical messengers
• Cell membranes - plasma membrane made mostly of phospholipids
Saturated versus Unsaturated
• Saturated fatty acids are straight and have single bonds
between all of the atoms
• These tend to be solid at
room temperature
• Fats and waxes
• Unsaturated fatty acids bend because of double bonds
between atoms
• These tend to be liquid at
room temperature
• Oils
Phospholipids
• The plasma membrane in all cells is composed mainly of
phospholipids
• Phospholipids have a polar phosphate group “head” and
two nonpolar fatty acid “tails”
Crash Course Video
• https://www.youtube.com/watch?v=H8WJ2KENlK0
Exit Slips
• Describe how the structure of fats and oils differ
from the structure of carbohydrates.
• Describe how a function of fats and oils is similar
to a function of carbohydrates.
Exit Slip Review
• Describe how the structure of fats and oils differ
from the structure of carbohydrates.
• Lipids and carbohydrates are both organic
macromolecules, but the structure of these molecules is
different because…
• Carbohydrates are made from carbon, oxygen, and hydrogen in
a 1:2:1 ratio while lipids are mostly carbon and hydrogen
• Carbohydrates exist as monomers (glucose) and polymers
(cellulose), while lipids can’t be broken down into monomers
Exit Slip Review
• Describe how a function of fats and oils is
similar to a function of carbohydrates.
• One function that is similar in lipids and
carbohydrates is that both types molecules are
used for energy storage and can provide energy
when broken down by the body.