FTM 1 - Basic Principles of Medicine

Eicosanoids

20-C regulatory molecules that can be synthesized from omega-3 and omega-6 fatty acids

Normal [K+] extracellular levels are ____________

3.5-5 mmol/L

microtubule arrangement in cilia and flagella

9+2

A patient with anemia caused by premature destruction of erythrocytes is found to have increased cholesterol content in his erythrocyte membranes. These erythrocyte membranes: A. Exhibit decreased membrane fluidity B. Display phophatidylserine in their outer membrane leaflet C. Also contain excess concentrations of collagen. D. Lack glycoproteins on their surfaces E. Have only a single layer of phospholipid forming their structures

A. Exhibit decreased membrane fluidity

ABC transporters

ATP Binding Cassette//Eukaryotes allow the active transport of molecules from the cytosol to the extracellular space Usually lipids are transported, or lipid-related compounds. Liver releases bile salts, cholesterol, and conjugated bilirubin into the bile ducts using respective ABC transporters

Microvilli are made primarily out of

Actin (25-30 actin microfilaments)

relative refractory period

After absolute refractory period, during hyperpolarization phase (would need a lot more, so not likely, but possible)

Colchicine

Anticancer -- prevents polymerization of microtubules (binds to unpolymerized tubulin), mitotic spindles breakdown

Vinblastine and Vincristine

Anticancer agent (MT inhibitor); CCS (M phase) -MOA: Binds tubulin in M phase and prevents polymerization of MTs -Use: Acute leukemia, hodgkin's dz, non-hodgkins lymphoma, breast carcinoma, bladder -Adverse effects: Peripheral neuritis (Vincristine)

When studying membrane glycoproteins, it was determined that removal of a terminal N-acetylgalactosamine from a large carbohydrate attached to an erythrocyte membrane protein resulted in those cells being classified as blood type O instead of blood type A. These findings indicate that carbohydrate residues such as N-acetylgalactosamine attached to erythrocyte proteins: A. Bury themselves away from the aqueous exterior environment B. Face the exterior of the cell and interact with the environment C. Flip-flop from the outer to the inner membrane leaflet D. Increase the hydrophobicity of lipids in the membranes E. Intercalate between phospholipids to increase their packing

B

A glycoprotein within a plasma membrane has which of the following characteristics? A. Attaches to cytoskeletal proteins B. Oriented toward the environment C. Peripherally attached to the membrane D. Found on both the membrane leaflets E. Ability to undergo flexion

B. Carbohydrate portions of glycoproteins and glycolipids are oriented toward the exterior environment. Can move, but does not have fatty acid tails to undergo flexion.

Pro-apoptotic

Bax and Bak

anti-apoptotic

Bcl-2

Taxol (paclitaxel)

Binds tubulin within assembled microtubules (doesn't allow mitosis)

During transfer through the epithelium, which side of the epithelium always contains the Na+K+ ATPase pump?

Blood side

Which of the following describes the fluid mosaic model of plasma membranes? A. Glycolipid monolayer with glycoproteins on inner leaflet B. Cholesterol-enriched microdomains devoid of proteins C. Phospholipid bilayer with flowing nature and embedded proteins D. Lipid bilayer with components that freely flip-flop between leaflets E. Statically arranged layers of phospholipids and cholesterol with proteins on the outside

C

Humans cannot add a double bond after __________ in fatty acids (startying from the carboxyl end)

C-9

A particular molecule of phosphatidylcholine is studied within a plasma membrane of a living cell. Which of the following characteristics is this molecule likely to possess? A. A stable, fixed arrangement of its structural components B. Continuous flip-flop from one leaflet to the other C. Fatty acid tails that undergo flexion D. Binding sites to cytoskeletal componenets E. Equal distribution on both sides of the bilayer

C. Fatty acid tails are part of phospholipid bilayer and can move around laterally around membrane (fluid mosaic)

The arrangement of a ligand receptor within a plasma membrane is best described as a/an A. Peripheral Protein B. Lipid-anchored protein C. Integral membrane protein D. Lipid raft E. Glycolipid

C. Ligand receptors are transmembrane proteins -- they are proteins so they cannot be a lipid, and since they go through the membrane, they must be integral membrane proteins.

Why is CFTR important in sweat?

Chloride ions are released into the extracellular lumen via CFTR, and sodium ions from the interstitial fluid bind to the ions in the duct to form NaCl (attracting water) Ducts include APR (airway, pancreatic, and reproductive) Chloride can reuptake in secretory ducts (due to CFTR), and chloride can return to epithelial cells (in CFTR, no reuptake, so sodium and chloride stay on skin (this is why its salty)

Protein Y is covalently linked to a fatty acid chain of a phospholipid of the inner leaflet of a cell's plasma membrane, but its structure does not extend to the hydrophobic core of the phospholipid bilayer. Therefore protein Y: A Has glycosylated regions facing the cytosol B. Functions as a ligand receptor C. Is a single-pass transmembrane protein D. Is oriented towards the cytosolic compartment E. Cannot undergo any type of motion in the membrane

D. Proteins attached to the membrane's inner leaflet will be oriented towards the cytosolic component of the cell.

Intrinsic apoptotic pathway...how does it work?

Death signal (DNA damage etc) --> BAK/BAX upregulated --> release of cytochrome c from mitochondria --> apoptosome is formed (apaf-1, cytochrome c and procaspase 9), --> caspase cascade

What is the fastest molecular motor?

Dynein

A peripheral membrane protein is best described as a protein: A. Embedded within the phospholipid bilayer B. That is transmembrane in nature C. That traverses the cytosol of a living cell D. Enclosed within the membrane infoldings of a caveola E. Loosely attached to the inner membrane leaflet

E - loosely attached to the inner membrane leaflet and NOT AN INTEGRAL PART OF THE MEMBRANE'S STRUCTURE

A plasma membrane of a healthy cell is observed to have caveolae. These structures are: A. Components of phospholipids B. Intercalated between cholesterol molecules C. Composed of disorderly phospholipids D. Regions with high carbohydrate content E. Cholesterol-enriched membrane invaginations.

E. They are lipid rafts which are orderly cholesterol-and sphingolipid-enriched microdomains.

Examples of high-affinity glucose transporters:

GLUT1 (RBCs), GLUT3 (brain and neurons), GLUT4 (insulin dependent --abundant in fat cells, skeletal muscle, and heart)

Examples of low-affinity glucose transporters

GLUT2 (release of ALL dietary monosaccharides into the portal vein) hepatocytes store glucose when high gluc levels after a meal --also works in pancreatic cells ("measures" high blood glucose levels) GLUT5 (prefers fructose -- intenstinal mucosal on the luminal side of the intenstinal membrane//also found in seminal vesicles for release of fructose into semen.)

Types of intermediate filaments

Keratins (1/2) Vimentin & vimentin-like (3) neurofilaments (4) Lamins (5) Beaded filaments (6)

What is used to determine fetal lung maturity?

Lecithin-sphingomyelin ratio

Leukotrienes

Mediators of allergic response // cause bronchoconstriction, itching when the body responds to an allergen

Prostaglandins

Mediators of inflammation//they cause pain, fever and redness at sites of inflammation

1-3 days after fertilization, what is formed?

Morula (day 3)

Na+/K+-AtPase (type of transport, how many Na/K

Primary active transport, 3 Na out/2K in//ATP-dependent

Sulfatide

Sphingosine + FA + Monosaccharide-sulfate

Globoside

Sphingosine + FA + oligosaccharide

Ceramide Structure

Sphingosine + fatty acid

Ganglioside

Sphingosine + fatty acid + oligosaccharide (contains NANA)

What causes platelet aggregation?

Thromboxane

cerebrosides contain ceramide with __________

a monosaccharide

estimation of _______________ are useful in patients with autoimmune disorders

anticardiolipin antibodies

Cholesterol is a precursor for

bile acid, bile salt, steroid hormones (cortisol, aldosterone, estrogen, progesterone, and testosterone), vitamin D

4-6 days after fertilization what is formed

blastocyst

About 6 days after fertilization the _________ attaches to the epithelium of the endometrium

blastocyst

the basolateral membrane lines the

blood

What is the most abundant phospholipid in the IMM?

cardiolipin (anticardiolipin antibodies estimations are useful in patients with autoimmune disorders)

What happens to a cell physiologically during apoptosis?

cell shrinks, DNA aggregates, plasma membrane remains intact, no surround tissues are damaged, no inflammation

What happens to a cell physiologically during necrosis?

cell unable to maintain homeostasis, cell swells, loss of plasma membrane integrity, cell contents are released, tissues surrounding are damaged, and there is inflammation, random DNA degradation

sphingosine is esterified to a fatty acid to form ___________

ceramide

4 types of glycolipids

cerebrosides, sulfatides, globosides, and gangliosides

4 classifications of glycolipids

cerebrosides, sulfatides, globosides, gangliosides

What does the cytotrophoblast do?

creates cells//mitotically active

CFTR

cystic fibrosis transmembrane conductance regulator SPECIAL ABC-transporter (more of a chloride ion channel than a transporter) NO pumping of chloride ions//they flow with the gradient once the channel is opened

inner layer of the trophoblast

cytotrophoblast

Cystic fibrosis

deficiency of CFTR//can be noticed in babies when they are kissed on the forehead -poor growth/low weight -recurrent lung infections -chronic pancreatitis -steatorrhea (excess fat in feces//oily and smell) -male infertility (vas def)

The higher number of _______ _________ in a(n) ________________ fatty acid results in ________________

double bonds, unsaturated, increased membrane fluidity (also leaves membrane susceptible to damage by free radicals)

Merocrine glands

exocytosis of membrane-bound vesicles (most common)

Phosphatidylchloine (lecithin)

glycerol + 2 fatty acids +phosphate +choline (also is an important component of surfactant in the alveolus)

What group of lipid does DPPC belong to?

glycerophospholipid

Two types of phospholipids

glycerophospholipids ( contain glycerol) and sphingophospholipids (contain sphingosine)

2 types of phospholipids

glycerophospholipids and sphingophospholipids

Glycolipids

glycosphingolipids/sphingoglycolipids

Effect on melting temperature as double bonds are decreased in fatty acids

increase

cardiolipin is abundant in the ______________

inner mitochondrial membrane

two types of apoptosis pathways

intrinsic, and extrinsic

extrinsic apoptotic pathway...how does it work?

ligand binds to death receptor (FAS ligand) --> recruitment of death domain adaptor proteins (FADD and TRADD) --> formation of death inducing signaling complex (DISC) --> caspase cascade

The apical surface of the epithelium lines the __________-

lumen

sulfatides contain ceramide +

monosaccharide and sulfate

purpose of goblet cells

mucus secretion

hypokalemia causes __________, why?

muscle weakness, cramps, spasms, respiratory slowing or failure, cardiac arythmia, paralysis steeper slope of depolarization/lower threshold for full depolarization.

What motor generates the force for skeletal muscle contraction

myosin II

absolute refractory period

no new action potentials are possible since not all of the Na+ are closed off

Give an example of an unsaturated fatty acid

oleic acid (olive oil )

globosides contain ceramide +

oligosaccharide

gangliosides contain ceramide +

oligosaccharide containing NANA

essential fatty acids

omega 3 (linoleic acid, alpha linoleic acid omega 6

Stain used for lipids

osmium tetroxide

glycolipids tend are mainly present on the _______ of the plasma membrane, as part of the _____________

outer leaflet (ECF-side), glycocalyx

Most common saturated fatty acids in humans

palmitic acid and stearic acid

What is the most abundant membrane lipid?

phosphatidylchloline (lecithin) --more on the ECM, but can be found in the ICM as well

Phospholipids mainly found in the ECM

phosphatidylcholine (PC), sphingomyelin

Examples of glycerophospholipids

phosphatidylcholine (lecithin), phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, cardiolipid

Phospholipids mainly found in the ICM

phosphatidylserine (PS), Phosphatidylethanolamine (PE), phosphatidyllinositol (PI)

2 subdivisions of complex lipids

phospholipids and glycolipids

Specialized cilia

photoreceptors, chemoreceptors, mechanoreceptors

Low levels of DPPC are most common in ____________, and put them at a high risk for ______________________________ due to _______________________

premature neonates, respiratory distress syndrome (RDS), collapse of the alveoli

apocrine glands

product released at apical surface surrounded by envelope of plasma membrane (lactating mammary gland)

holocrine glands

programmed cell death releases secretory product and cell debris (sebaceous glands of skin)

Two classes of eicosanoids

prostaglandins and leukotrienes

three stages of cell movement (actin)

protrusion (lamellipodium), attachement (integrin proteins), contraction

autocrine gland

same cell

SGLT is what kind of transport, and what does it bring in

secondary active transport --coupled to Na/K ATPase

paracrine gland

secretes products into connective tissue, then bloodstream ( goes to nearby cells)

What type of lipid is most abundant in the myelin sheath?

sphingomyelin

Cerebroside

sphingosine + fatty acid + monosaccharide

outer layer of trophoblast

syncytiotrophoblast

A L/S ratio greater than 2 implies ______________

that the fetal lung is mature and there is a low risk for RDS

A L/S ratio less than 1.5 implies___________

that the fetal lung is not mature enough, and there is a higher risk of RDS in these infants

triacylglycerol

three fatty acids linked to one glycerol molecule

Example of a simple lipid

triacylglycerol

hyperkalemia causes __________, why?

weakness and paralysis some Na+ channels open and close, but never reset//membrane potential will be stabilized with fewer active Na channels