Lipids Flashcards
What is the significance of the hydrophobic core in cell membranes?
The hydrophobic core acts as a barrier to water-soluble molecules
Preventing them from crossing the cell membrane freely.
How does the composition of fatty acid tails affect the fluidity of the cell membrane?
Saturated fatty acid tails: make the membrane less fluid.
Unsaturated fatty acid tails: make the membrane more fluid.
What creates a hydrophobic core in a phospholipid bilayer?
The presence of hydrophobic fatty acid tails creates a hydrophobic core when a phospholipid bilayer forms
Acting as a barrier to water-soluble molecules.
What is the main component of cell membranes?
The main component (building block) of cell membranes is phospholipids.
Why are phospholipids important in cell membranes?
Their amphipathic characteristic allows them to form bilayers
Which create a barrier between the interior of the cell and the external environment.
What are the hydrophilic parts of phospholipids?
Phosphate groups
What are the hydrophobic parts of phospholipids?
Fatty acid tails
What does amphipathic mean in the context of phospholipids?
Amphipathic means that a molecule has both hydrophilic and hydrophobic characteristics.
Define the term ‘hydrophilic’ as used in the context of phospholipids.
Hydrophilic refers to the property of being attracted to water, which applies to the phosphate head of phospholipids.
How do the properties of phospholipids contribute to cell membrane structure?
Phospholipids have a hydrophilic (polar) head and hydrophobic (non-polar) tails
Allowing them to form bilayers that create a barrier in cell membranes.
What characteristic do the fatty acid tails of phospholipids have?
The fatty acid tails are non-polar, which makes them insoluble in water (hydrophobic).
What is the solubility of phosphate in water?
Soluble in water (hydrophilic).
What replaces one of the fatty acid tails in a phospholipid molecule?
A phosphate ion (PO₄³⁻)
What are the two main functions of lipids mentioned?
Lipids function as components of cell membranes and serve as energy storage.
Is the phosphate head in a triglyceride polar or non-polar?
The phosphate head in a triglyceride is polar
What is the presence of phosphate in a triglyceride?
A triglyceride does not have a phosphate group.
How many fatty acid tails does a triglyceride have?
A triglyceride has 3 fatty acid tails.
What is a triglyceride?
A triglyceride is a type of lipid made up of three fatty acid tails and is primarily used for energy storage.
Uses of triglycerides?
Energy Storage
Insulation
Storage Molecule
Waterproofing (waxy cuticle)
Uses of phospholipids?
Cell membrane component
Emulsifier
Test for lipids?
Crush/Grind food
Add ethanol and shake (With bung)
Decant/Add water
If lipids are present milky/white emulsion will form (Do NOT say cloudy)
Unsaturated fatty acid
A fatty acid with one or more double bonds between carbon atoms
Saturated fatty acid
A fatty acid with single bonds between carbon atoms
Features that help triglycerides to function as energy storage molecules
long hydrocarbon tails
low mass to energy ratio
insoluble
high ratio of hydrogen to oxygen atoms
What type of organic chemical is glycerol?
Alcohol
What is the term for a fatty acid chain that has more than one carbon-carbon double bond?
Polyunsaturated
Why do active organisms use lipids as an energy source and not polysaccharides?
Double the energy can be stored due to the low mass:energy ratio
Phospholipids have 2 ends that behave differently, this means they are referred to as being?
Polar
