Ch 11 Lipids Flashcards
(18 cards)
Where are glycoproteins found?
A. In the inside of the cells on the endoplasmic reticulum
B. In the inside of the cells, near the nucleus
C. On the outside of the cells, attached to the outer layer of lipids
D. On the outside of the cells, attached to the plasma membrane
E. In lysosomes
D. On the outside of the cells, attached to the plasma membrane
On what amino acid does the linkage to form proteoglycans occur?
A. Aspartate
B. Glycine
C. Serine
D. Proline
E. Glutamate
C. Serine
Define saturated fatty acids
These have no double bonds between carbon atoms; all carbon atoms are fully saturated with hydrogen
Define saturated fatty acids
These contain one or more double bonds. They can be further categorized into:
Monounsaturated Fatty Acids and
Polyunsaturated Fatty Acids
Define monounsaturated fatty acids
One double bond (e.g., oleic acid)
Define polyunsaturated fatty acids
Two or more double bonds (e.g., linoleic acid, which has two double bonds).
Saturated vs. Unsaturated Fatty Acid saturation
Saturated: Higher melting points, solid at room temperature, commonly found in animal fats.
Unsaturated: Lower melting points, liquid at room temperature, commonly found in plant oils.
Define the Delta (Δ) Numbering System
This system counts the carbon atoms in the fatty acid chain from the carboxyl end (the α-end) and indicates the position of double bonds.
Define the Omega (ω) Numbering System
This system counts from the opposite end of the fatty acid (the methyl end, or ω-end).
What is the structure of Triacylglycerols
are a type of lipid formed from glycerol and three fatty acids
what are glycerols
A three-carbon molecule with each carbon attached to a hydroxyl group (–OH)
How are Triacylglycerols formed? What is this process?
Esterification: where the hydroxyl groups of glycerol react with the carboxyl groups of fatty acids
What are the functions of Triacylglycerols
energy storage, insulation and protection, and structure
What is the function of Triacylglycerols in adipose tissue?
To serve as a long-term energy storage molecule in the body, primarily stored in adipose tissue, where it is released as needed to provide energy between meals; essentially acting as a “fat reservoir” for the body
Define phospholipids and their structure/function
Glycerol backbone, phosphate group, fatty acid tails
Phospholipid bilayer
- Contain a phosphate and are a major component of cell membranes.
- amphipathic, meaning they have both hydrophilic (polar) and hydrophobic (nonpolar) regions.
- They are also ideal emulsifiers because they can mix with both water and fat
Fluidity and Permeability
Define Sphingolipids and their structure/function
Fatty acid, polar had, sphingosine backbone
Signal transduction: Sphingolipids modulate the clustering and dynamics of membrane receptors, which is important for signal transduction.
Inflammation: Sphingolipids play a role in inflammation.
Cell differentiation, proliferation, and apoptosis: Sphingolipids are involved in these processes.
Define Sterols and their structure/function
Steroid backbone and functional groups
Have a four-ringed structure with a hydrophobic tail and a hydroxyl group at opposite ends.
- maintain the optimal FLUIDITY of the cell membrane by interacting with phospholipids, preventing the membrane from becoming too fluid at high temperatures or too rigid at low temperatures.
Signal molecules
What is an example of sterols?
Cholesterol is a sterol that is present in all body cells and is an important substance in cell membrane structure. Cholesterol is also used to synthesize vitamin D, bile, and sex hormones.
