DLA 1-3 Flashcards
What are the three major classes of lipids in the cell membrane?
phospholipid
cholesterol
glycolipid
PM have two types of proteins?
integral- in or pass through bilayer
peripheral - one side of the bilayer
What are the 6 integral membrane proteins?
- pumps,carriers, transporters
- channels
- receptors
- linker
- enzymes
- structural
What is a glycocalyx and what is its purpose?
it is a carbohydrate rich region containing glycolipids, glycoproteins, and proteoglycans
Function:
- protection
- cell recognition
- cell to cell interaction
What are the three types of endocytosis?
- pinocytosis
- phagocytosis
- receptor-mediated
what types of endocytosis are clathrin independent?
pinocytosis and phagocytosis
Is receptor-mediated endocytosis clatherin independent or dependent?
clatherin dependent
What are the two kinds of exocytosis?
regulated (secretory cells)
constitutive (no stimulus)
What are the four different types of receptor mediated endocytosis?
1 .Receptor recycled, ligand degraded
- Receptor and ligand degraded
- Receptor and ligand recycled
- Receptor and ligand transcytosis
Example of receptor recycled, ligand degraded
LDL receptor
Insulin-glucose transporter receptor
Example of Receptor and ligand degraded
Epidermal growth factor (EGF) & receptor
Example of Receptor and ligand recycled
Iron, transferrin & transferrin receptor
• Major histocompatibility complex I & II
Example of Receptor and ligand transcytosis
Secretion of immunoglobulins (secretory IgA) into saliva
• Secretion of maternal IgG into milk
What are steps of phagocytosis?
- particle binds to PM receptor (antibody)
- Extension of pseudopods (actin polymerization)
- phagosome fuses with lysosome (digestion)
- residual body (indigestible substances)
How does receptor mediated endocytosis work?
- clathrin molecule interact with adaptin
- clathrin forms a cage (drives vesicle formation)
- dynamin mediates the pinching off of the vesicle
What are the pathways to lysosomal digestion?
- phagocytosis
- endocytosis
- autophagy (self-eating) (autophagosome is formed)
Describe the proteosome?
used for protein degradation
ATP dependent
no lysosome needed
How are proteins sent to the proteosome?
They are tagged with ubiquitin
What is the partition coefficient?
It is used to measure the lipophilicity of molecules
how a substance partitions itself between two immiscible substances
What is the partition coefficient equation?
conc of substance in oil / conc. of substance in water
the scale is 0-1 for Partition coefficient?
1 = substance will equally exist as a solute in water and oil
greater than 1 = substance is lipophilic and can pass membrane
less than 1 = only soluble in water and cannot pass membrane easily
What is the permeability coefficient?
The degree, in which, a substance can pass through a membrane
scale for the permeability coefficient?
1 = will pass membrane easily
0 = cannot pass the membrane
What is the reflection coefficient?
How easily a substance can cross a membrane based on reflection
The scale for the RC?
1 = does not pass membrane
0 = passes membrane
Epithelial transport?
Solute transport across the two membranes of cells that line hollow organs or tubes in order to reach the blood from the lumen or vice versa
pass through the apical membrane and basolateral membrane
What is absorption?
movement of solutes/fluid from lumen to blood
What is secretion?
movement of solutes/fluid from blood to lumen
Where the is Na/K pump located?
Always on the basolateral membrane
eNAC and CFTR channels?
When the eNAC channel is upregulated the CFTR channel is downregulated (vice versa)
Cl- is pumped into the apical membrane
Na is pumped into the cell
What are two types of saturated fatty acids?
- Palmitic acid (C16)
2. Stearic acid (C18)
What is the significance of saturated fatty acids?
components of TAG, phospholipids, and glycolipids
they decrease membrane fluidity
What are examples monounsat FA?
Oleic acid (C18)
What is the importance of oleic aid
components of TAG, phospholipids, and glycolipids
Examples of polyunsat fatty acids?
omega-6 and omega-3
importance of polyunsat fatty acids?
components of TAG, phospholipids, and glycolipids
increase membrane fluidity
examples of omega-3 FA’s?
alpha- linolenic acid
Eicosapentaenoic acid
Docosahexaenoic acid
Importance of Omega-3 FA’s?
components of TAG, phospholipids, and glycolipids
increase membrane fluidity
examples of omega-6 FA’s?
linoleic acid
arachidonic acid
Importance of omega-6 FA’s?
components of TAG, phospholipids, and glycolipids
increase membrane fluidity
What are the essential fatty acids?
alpha- linolenic acid and linoleic acid
Importance of the essential fatty acids?
components of TAG, phospholipids, and glycolipids
increase membrane fluidity
Long vs short FA chains in membrane?
short chains make membrane more fluid, while longer chains decrease fluidity
Double bonds vs single bonds related to membrane fluidity?
Double bonds make the membrane more fluid and single blonds decrease fluidity
Functions of cholesterol?
- Regulates membrane fluidity
- precursor of steroid hormones
- precursor for Vit D synthesis
What are the two types of phospholipids?
glycerophospholipids
sphingophospholipids
Examples of glycerophospgolipids?
phosphatidylcholine
phosphatidylethanolamine
phosphatidylserine
phosphatidylinositol
example of sphingophospholipids?
sphingomyelin
What are the four types of glycolipids?
- cerebrosides
- sulfatide
- globoside
- ganglioside
what is the structure of cerebroside?
sphingosine + FA + monosaccharide
what is the structure of sulfatide?
sphingosine + FA+ sulfate
what is the structure of globoside?
sphingosine + FA + oligosaccharide
what is the structure of ganglioside?
sphingosine + FA+ oligosaccharide with NANA
Where are glycolipids found?
The glycocalyx
What is the typical structure of glycerophospholipids?
Glycerol (backbone)
one saturated FA
one unsaturated FA
nitrogen base
Describe phosphatidic acid?
This molecule is a building block phospholipids but is not in the membrane itself because it is missing a base.
What is cardiolipin?
It is a glycerophospholipid found only in the inner membrane of mito.
can be involved in autoimmune disorders: anticardiolipin antibodies
What Glycerophospholipids are found in the outer leaflet of the membrane?
phosphotidylcholine
sphingomyelin
What Glycerophospholipids are found in the inner leaflet of the membrane?
phosphotidylserine
phosphotidylethanolamine
phosphotidelinostiol
What phospholipid is in surfactant in lung tissue
DPPC
this prevents the alveoli from collapsing
What can lead to respiratory distress syndrome (RDS)?
Smoking because it kills type II cells
premature babies
Amniotic fluid Lecithin-Sphingomyelin ratio?
A ratio to determine the chance of RDS in babies
greater than 2 = mature fetal lung
less than 2 = immature fetal lung
What is DPPC?
A Glycerophospholipid
What is the structure of Sphingophospholipid?
sphingosine backbone
fatty acid
phosphate attached to a choline
makes up myelin
What is the composition of phosphatidylcholine?
glycerol
2 FA’s
phosphate
choline
Function of phosphatidylcholine?
lung surfactant
What is the composition of phosphatidylserine?
glycerol
2 FA’s
phosphate
serine
Function of phosphatidylserine?
may indicate apoptosis if in outer leaflet
composition of phosphatidylinositol?
glycerol
2 FA
phosphate
inositol
Function of phosphatidylinositol?
forms second messengers
composition of phosphatidylethanolamine?
glycerol
2 FA
phosphate
ethanolamine
