Because of the carbon- hydrogen bonds, lipids store more energy per gram than carbs.
22
Chapter 3 Section 2 cont. Lipids and Nucleic Acids
-
Upload
melvyn-jenkins -
Category
Documents
-
view
221 -
download
4
Transcript of Because of the carbon- hydrogen bonds, lipids store more energy per gram than carbs.
Chapter 3Section 2 cont.
Lipids and Nucleic Acids
Lipids are large, nonpolar molecules
Lipids include
1) triglycerides
2) phospholipids
3) steroids
4) waxes
5) pigments
The structure of lipids:Lipids have a lot of carbon
and hydrogen atoms; the ratio of carbon and hydrogen atoms to oxygen atoms is much higher than in carbohydrates
Lots of energy…
Because of the carbon-hydrogen bonds, lipids store more energy per gram than carbs
The role of lipids in us:Store energy
Compose cell membranes
The monomer of lipids: fatty acids
Fatty acids – a subunit of many lipids
Consist of a long carbon chain with a carboxyl group at one end which makes it polar
The polar end of the molecule
LOVES WATER!
It’s called hydrophilic.
Talk about sea legs! Sea otters eat, sleep, hunt, mate, and give birth in the water.
But the other end of the fatty acid molecule is hydrophobic
It “fears” water!
2 types of fatty acids:Saturated- carbon atoms
have every available bond attached to hydrogen
Solid at room temp. Found in animal products; red meat, butter
And unsaturated- there are some double bonds between carbon atoms
Liquid at room temperature; plant oils
Trans fats are unhealthy…
Phospholipids Composed of
1) 2 fatty acids
2) glycerol
3) a phosphate group
Phospholipids make up our cell membranes…
2 layers of phospholipids (a bilayer) form our cell membranes
Other views:
The cell membrane…
The tail ends face each other because they do not like water.
The head ends face outward because they like water (and cells are surrounded by and filled with aqueous solutions).
Wax A structural lipid that
forms a waterproof covering in plants or in our ears to keep microorganisms out
Consists of a long fatty-acid chain joined to a long alcohol chain
Steroids
Unlike other lipids, not composed of fatty acids
Ex. Testosterone OR
Ex. Cholesterol- needed by the body for nerve and other cell function
Nucleic AcidsTwo
types:
1) DNA
2) RNA
The monomers of nucleic acids are nucleotides.
A nucleotide contains:
1) a phosphate group
2) a nitrogenous base
3) a sugar
DNA RNA
Holds genetic
information
Aids in the making of proteins (protein synthesis
