Chapter 3 Flashcards
What is the cell membrane primarily composed of?
Phospholipid bilayer (back-to-back phospholipids)
What contributes to the fluidity of membrane?
Cholesterol
What is the difference between saturated and unsaturated fatty acids?
Unsaturated fatty acids result in kinks in the hydrophobic tails
Hydrophobic definiton
repels water
Hydrophilic definition
attracts/likes water
What is an amphipatic molecule?
Molecule that ocntains both a hydrophillic and hydrophobic region
T/F - Phos. bilayer is very rigid and hard
NO. Phos. bilayer is very fluid
What parts of the phospholipid bilayer touch the cytosol and ECF?
The hydrophobic heads
Which part of Phos. bilayer is hydrophobic and hydrophilic?
Head - Hydrophilic (non-polar)
Tail - Hydrophobic
What is the intracellular fluid (ICF)
Fluid interior of the cell
What is the extracellular fluid (ECF)
A watery medium environment outside of the enclosure of the cell membrane
What is interstitial fluid (IF)
extracellular fluid not contained within blood vessels
What is a glycoprotein?
Protein with carbohydrate attached
What is a glycolipid?
Lipid with a carbohydrate attached
What is an integral protein?
Protein within/embedded in the membrane
What is a channel protein?
Integral protein that allows particular materials to enter/exit cell
What do recognition proteins do?
Mark a cell’s identity so others can recognize it
What is a ligand?
specific molecule that binds to and activates a receptor
What is glycocalyx?
Fuzzy appearing sugar coating around the cell; formed from glycoproteins and other carbohydrates attached to the cell membrane
What is glycocalyx important?
It gives each of the individual’s trillions of cells the “identity” of belonging in the person’s body. This identity is the primary way that a person’s immune defence cells “know” not to attack the person’s own body cells, but it also is the reason organs donated by another person might be rejected.
What are peripheral proteins?
Proteins bound on the inner/outer surface of the lipid bilayer
What regulates the concentration of substances?
Cell membrane
What is Passive Transport?
transport of materials without use of cell energy
What is active transport?
transport of materials using ATP
What is selective permeability?
A cell’s ability to allow only substances meeting certain criteria to pass through it unaided
What is the criteria to pass through the cell membrane? (What must the substance entering be?)
relatively small, nonpolar materials
What is a concentration gradient?
The difference in concentration of a substance across a space. Molecules/ions will spread/diffuse from where they are more concentrated to where they are less concentrated until they are equally distributed in that space.
what is diffusion?
The movement of particles from an area of higher concentration to an area of lower concentration
T/F The higher the temperature, the quicker the diffusion
TRUE