Lipids! But first…Do Now:

In our pectinase experiment:

What is the independent variable?

What is the dependent variable?

What is the control group?

What variables were constant for both samples?

Lipids: What’s a Lipid anyhow?

• Lipids come in a variety of shapes and sizes.

• The one thing all lipids have in common is the fact that they can’t dissolve in water. They’re hydrophobic.

What do Lipids do?

Honeybee hives are made out of a type of lipids called waxes

Structure

What do Lipids do?

Earwax helps prevent bacterial infections

Defense

What do Lipids do?

Estrogen is the female sex hormone in humans.

Hormones

What do Lipids do?

Fats can store lots of energy

Energy Storage

But most Importantly, a lipid bilayer surrounds EVERY LIVING CELL

Cell membranes are made of phospholipids

Hydrophilic “head”

Hydrophobic “tail”

A Cell Membrane has lots of phospholipids

Cell Membrane = Phospholipid Bilayer

Hydrophobic

Hydrophilic

Hydrophilic

Aren’t Fats bad for you?

Yes and No…

Trans-fatty acids common in processed foods have been linked to heart disease

But some are healthy

Omega-3 fatty acids common in fish have been shown to HELP cardiovascular health!

Careful – They store a lot of energy!

The bottom line on lipids• Lipids are NOT soluble in water.

• Lipids are not made of monomers like the other macromolecules.

• Lipids have many functions, from earwax to hormones.

• Lipids are used for LONG-TERM energy storage, since they can’t be used directly by cells

• Cell membranes are made of a lipid bilayer.