OMNI - FAMM Exam 1

What does homestatsis regulate?

the internal environment- intersitial fluid, vascular fluid

What did Walter Canon do?

Coined the term homeostatis

What did Claud Bernhard do?

defined the internal body environment as extracellular fluid

Equalibrium vs steady state

• equilibrium is a thermodynamic concept fueled by enropy

• Steady state is when a equal input and output of a system is maintained needing energy input.

Negative feedback loop

Error in homeostasis is defined as:

set point - Compesated value

• compensated value: value after feedback loop has finished

• uncompensated value: when feedback loop is triggered

• closer error is to 0 the better

Gain is defined as

A measure of how good homeostasis is maintained. More negative is higher gain

=Correction/error

• correction: uncompensated-compensated

How are problems assessed through skeletal-muscular intervention in osteopathic medicine

What produces the error signal

control center

what generated feedback signal?

sensors

Important monosaccharides

Important dissacharides

N-glycosidic bonds

when a carbyhydrates anomeric carbon is attached to the nitrogen of another molecule

• found in nucleic acids

O glycosidic bonds

where an anomeric carbon forms a bond with an oxygen of another molecules

• most common in dissacharides

What configuration are unsaturated fatty acids in humans

cis, trans is difficult to digest

Phosphaticacid

precursor to phospholipids

Sphingolipids

do not have a glycerol backbone, have a sphingosine group instead

Ceramides

an amide bond between sphingosine and fatty acid

Steroid structure

steroid hormones are made through the modification of the alkyl side chain

How is a DNA polymer formed

the 3’ sugar in the incoming chain is added to the 5’ through a phosphodiester bond

Proline is:

• an Imino acid (-NH instead of -NH2)

• ridged due to cyclic structure

• is typically at turns in tertiary structure

Aromatic Amino Acids

• absorb UV light

• most hydrophobic: tyr → Try → Phe

Ambivalent amino acids (to water)

• alanine

• glycine

• proline

Modifications

• lipid addition

• gycosylation

• phosphorylated- typically to regulation of enzymes

• oxidation/carboxylation

Chaperone proteins in ER

• calnexin (membrane)- especially helps glycoproteins fold propperly

• caltreticulin (lumen)

Disulfide protein isomerase

a chaperone protein in ER that forms disulfide bonds with cysteine and stablizes structure

Unfolded Protein Response

In the ER, detects misfolded proteins and increases the amount of chaperone proteins. If this doesn’t work, ERAD (ER-Associated protein degredation) is triggered. After misfolded protein was tagged with ubiquitin 4 times

Proteosome

a protease complex meant for digesting proteins tagged with ubiquitin, recycles amino acids

Protein regulatory mechanisms

• phosphorylates

• protein-protein interaction (a bound inhibitor protein)

• cleavage

These are typically triggered by cell signaling, such as by cAMP

How can phosphylization change protein behavior

• turning enzymes on/off

• localization

• stability

• interactions

How is lipidation of a protein helpful?

allows a largely hydrophilic protein to assaociate with membranes

Histome acetylation

adding an acetylgroup to histones can effect how tightly wound DNA is. Acetylation loosens histones through disrupting electrostatic interactions between Amino acids and DNA, turning on a gene

Gene Methylation

effected by envirnmental conditions, a methylated gene is off. Aka epigenetics

What amino acids are methylated

lysine and arginine

Glycosylation

Addition of sugars to a protein. Helps to: prevent agregatition, surface signals/receptor, protein tagging

glycoprotein examples

• many excreated proteins

• lysosomal proteins

N vs O linked gycloproteins

N- linked

• When carbohydrate is attached to amino

• In ER, for membrane proteins

O-linked

• when carbyhydrate is attached to -OH of serine or threonine

• Common in mucous proteins

• In ER, Golgi, Cytoplasm

Proteoglycans

• chains of repreating GAG’s attached to proteins, heavily branched component of extracellular matrix

• resists compression

• binds to cations

• binds to water for lubrication

GAGs (Glycosaminoglycans)

polysaccharide chains of repeating amino sugars + acid sugar

• highly negative charged

• high capacity for binding to water

Approximate membrane composition

• proteins- 55%

• phospholipids- 25%

• Cholesterol- 13%

• Other lipids- 4%

• carbohydrates- 3%

Aproximate composition of membrane lipids

• 75% phospholipids

• 20% cholesterol

• 5% glycolipids

• <1% shingolipids, mainly in nerve cells

Na+/k+ ATPase pump

• on plasma membrane, used in action potentials

• 1 ATP moved 3 Na out and 2 K comes in

• Cardiac glycosides like digoxin inhibits this channel by binding to E2 conformation

glycocalyx

carbohydrates enxending outside the cell on glycoproteins

• lubrication and protection

• anchoring cell in place or locomotion

• receptors

• self recognition

enzymes that move phospholipids within the plasma membrane

How does cholesterol effect membrane fluidity

• low temp: prevents close packing to avoid solidification

• high temp: restricts phospholipid movement to stabilize membrane

spontaneous vs protein mediated fusion

• protein mediated is though the use of snares to fuse the vesical

• no snares are nessicary, when put at the plasma membrane the vesical will fuse. Such as neurotransmitter leak and

Signal recognition particals vs importin

both recognize amino acid localization squeinces, SRP goes to ER while importing goes to nucleous. SRP will pick it up before it’s done translating, while importin is post translational.

what substance increase in neurons and muscle with age

Lipofuscin- a aging pigment caused by undigested cellular components that accumulate in lysosomes. Typically yellow-brown and common in long loved cells.

Where is actin and tubulin synthesized

in the cytosol, since these are components of the cytoskeleton

what cell inclusion is an iron-strage complex

hemosiderin- literally an iron inclusion within cells. commonly found in macrophages and hepatocytes after the metabolism of red blood cells.