Unit #2: Lipids and Cell Membrane Dynamics Flashcards
What are the monomers of lipids?
Glycerol and fatty acids.
What is the polarity/water affinity of lipids?
Non-polar, hydrophobic
What is the dehydration linkage between lipids called?
Ester linkage
What is the difference between the structure of a saturated and unsaturated fatty acid.
A saturated fatty acid has has space for as many hydrogens as possible, therefore is made of all single bonds between C and Hs, where an unsaturated fatty acid contains at least one trans or cis bond.
What is the difference between a trans and cis bond.
A trans bond occurs when there is a double bond and the hydrogens are on opposing sides, but a cis bond occurs when the hydrogens are on the same side of the double bond.
Which fatty acid has a kink in its structure and why.
Unsaturated fatty acids due to the double bond.
Which bond causes a kink of a higher degree in unsaturated fatty acids and why.
Cis bonds, due to the hydrogens being on the same side of the double bond.
How are phospholipids amphipathic?
Hydrophilic head and hydrophobic tails, has 2 affinities.
How are phospholipids arranged in phospholipid bilayers?
Head out tails in
What are the two structures that phospholipids may form in water.
Micelles (rings) and phospholipid bilayers.
How do steroids affect fluidity of phospholipid bilayer?
Reduce freezing and fluidity.
What are carbs bound to proteins called?
Glycoproteins
What are the two types of proteins on a cell membrane?
Integral and peripheral proteins
Are integral proteins hydrophilic or hydrophobic and why?
Both! They are amphipathic because they span throughout the whole membrane, therefore they need both hydrophobic and hydrophilic parts.
Are peripheral proteins hydrophilic or hydrophobic and why?
Hydrophilic, because they are located on the outer edge of the membrane.
In order of importance, what are the factors affecting what can pass through the semi permeable membrane?
1-2. Size, 1-2. Charge, 3. Polarity
Is diffusion active or passive transport and why.
Passive, because the concentration gradient is the moving force, since the solutes move from high to low concentration.
Define osmosis
The process of water moving from high to low concentration when non penetrating solutes are unable to.`
Compare osmolarity and tonicity
Osmolarity is in regards to all solutes while tonicity is in regards to non penetrating solutes
What tonicity of solution do animal cells want to be in.
Isotonic
What tonicity of solution do plant cells want to be in.
Hypotonic
What are the two types of diffusion and what makes them different.
Simple and facilitated diffusion, in simple diffusion solutes move freely, but in facilitated diffusion, solutes need a transport protein to be able to diffuse through the membrane.
What two types of proteins are used in facilitated diffusion.
Channel proteins and carrier proteins.
What is active transport?
Transport against a concentration gradient, requiring energy.
