60 Questions
What is the main reason why lipids form various structures in an aqueous environment?
Hydrophobic interaction
What is the characteristic of plant membranes compared to animal membranes?
Higher percentage of unsaturated fatty acids
What is the term for the lateral motion of components in the membrane?
Fluidity
What is the function of integral proteins in the membrane?
To transport substances across the membrane
What is the term for the movement of molecules against a concentration gradient linked to the hydrolysis of ATP?
Primary active transport
What is the term for the movement of molecules down an electrochemical gradient to drive the uphill transport of another ion/molecule?
Secondary active transport
What is the characteristic of lipid bilayer asymmetry?
Compositions on the inside and outside of the lipid bilayer can be different
What is the term for the simple diffusion of a molecule or ion through an opening?
Simple diffusion
What is the function of peripheral proteins in the membrane?
To bind to the membrane by electrostatic interactions
What is the term for the binding of Na+ ions to the enzyme, followed by phosphorylation and release of ADP?
Na+/K+ ATPase
What is the main difference between saturated and unsaturated fatty acids in terms of their structure?
They have different numbers of double bonds between carbons
What is the functional group attached to the glycerol molecule in phospholipids?
A modified phosphate group
What is the purpose of the kinks in the tails of fatty acids in phospholipids?
To make the plasma membrane more fluid
What is the characteristic of waxes that makes them resistant to degradation?
Their connection to carbon chains containing alcohol functional groups
What is the function of cholesterol in the animal cell membrane?
To maintain the fluidity of the membrane
What is the difference between LDL and HDL cholesterol?
LDL cholesterol raises the risk for heart disease and stroke, while HDL cholesterol lowers the risk
What is the function of testosterone and estrogen?
To regulate the concentration of certain hormones in the body
What is the main characteristic of steroids?
They are composed of four fused carbon rings
What is the function of phospholipids in the cell?
To form the plasma membrane of cells
What is the main difference between triglycerides and phospholipids?
Triglycerides are used for energy storage, while phospholipids are used for membrane structure
What is a common feature of lipids?
They are non-polar and hydrophobic
What is the primary function of lipids as an energy source?
To store energy for future use
What is the characteristic of a fatty acid with a kink in its hydrocarbon chain?
It is an unsaturated fatty acid with a cis-double bond
What is the term for a fatty acid that contains no carbon-carbon double bonds?
Saturated fatty acid
What is the general length of fatty acids in terms of carbon atoms?
16-18 carbon atoms
What is the effect of cis-double bonds on the conformation of fatty acids?
It causes a kink in the hydrocarbon chain, increasing fluidity
What is the characteristic of most membrane lipids?
They are amphipathic, having a non-polar and polar end
What is the term for lipids that contain a fatty acid and a glycerol molecule?
Triacyl glycerols
What is the role of lipids in cell membranes?
They provide a barrier to the cell
What is the characteristic of unsaturated fatty acids?
They contain one or more C=C bonds
What is the primary function of lipids as an energy source?
To store energy for long-term use
What is the main characteristic of amphipathic lipids?
They have a non-polar and a polar end
What is the effect of the length of a fatty acid on its chemical character?
It affects its ability to interact with other molecules
What is the main difference between saturated and unsaturated fatty acids?
The presence or absence of double bonds
What is the function of lipids in insulation and protection?
To provide a barrier against cold temperatures
What is the characteristic of fatty acids that contain only C-C bonds?
They are saturated
What is the main characteristic of phospholipids?
They have a glycerol molecule and a fatty acid
What is the effect of cis-double bonds on the conformation of fatty acids?
They cause a kink in the hydrocarbon chain
What is the main characteristic of waxes?
They are resistant to degradation
What is the function of steroids in the body?
To act as hormones or vitamins
What is the main reason for the difference in melting points between saturated and unsaturated fatty acids?
The presence of cis-double bonds in unsaturated fatty acids
Which type of lipid is composed of four fused carbon rings and is amphipathic?
Steroid
What is the function of HDL cholesterol in the body?
To absorb cholesterol in the blood and carry it back to the liver
What is the characteristic of waxes that makes them solid at room temperature?
They have a long-chain fatty acid connected to a carbon chain containing an alcohol functional group
What is the main difference between saturated and unsaturated fatty acids in terms of their physical properties?
Saturated fatty acids are solid at room temperature, while unsaturated fatty acids are liquid
Which type of lipid forms a lipid bilayer in water?
Phospholipid
What is the function of cholesterol in the regulation of hormones?
Cholesterol is the precursor molecule for several other steroids
What is the term for the type of lipoprotein that carries cholesterol from the liver to the bloodstream?
LDL
What is the characteristic of phospholipids that makes them hydrophobic?
The presence of a non-polar fatty acid tail
What is the function of unsaturated fatty acids in phospholipids?
To keep the plasma membrane fluid across a range of temperatures
What is the main force driving the formation of lipid bilayers?
Hydrophobic interaction
Which type of membrane has a higher percentage of unsaturated fatty acids?
Plant membrane
What is the characteristic of lipid bilayer asymmetry?
Different composition of inner and outer layers
What is the function of integral proteins in the membrane?
To be embedded in the lipid bilayer
What is the term for the transport of molecules against a concentration gradient linked to the hydrolysis of ATP?
Primary active transport
What is the characteristic of membranes at higher temperatures?
More disordered and fluid
What is the term for the carrier-mediated transport of molecules across the membrane?
Facilitated diffusion
What is the characteristic of the fluid mosaic model?
Lipid bilayer with fluid and dynamic lipids and proteins
What is the function of the Na+/K+ ion pump in the membrane?
To transport Na+ ions out of the cell and K+ ions into the cell
What is the characteristic of prokaryotic membranes?
Most fluid and dynamic membrane structure
Test your knowledge of lipids, including their structure, functions, and types such as fatty acids, triglycerides, phospholipids, and steroids. Learn about their roles in energy storage, cell membranes, and more.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
