• alanine
• valine
• leucine
• isoleucine
• phenylalanine
• trytophan
• methionine=sulfur R-group, makes sulfide bonds 
• proline=disruptive to regular structure
• glyceine=has smallest R-group, a proton

• serine
• tyrosine
• threonine
• asparagine
• cysteine=forms disulfide bonds when oxidized w/another cysteine
• glutamine

• these are proton donors 
• asparctic acid
• glutamic acid

• these are proton acceptors 
• histidine
• lysine
• arginine

• stereoisomers that appear to be mirror images, but are not superimpsoible
• L & D forms
• L=used for protein synthesis, more common

• xanthrophyls found in eye
• lutein=retinal periphery
• zeaxanthin=macula

• phosphate=w/in cells
• bicarbonate=extracellular pH
• protein=most imp. both inside and outside

• Ka=dissociation constant=(H+)(A-)/(HA)
• pKa=-logKa
• ph=pKa+log(A-/HA)   A-=conj. base

• pH at which the a.a. is electrically neutral

• primary=a.a. sequence, peptide bonds join the alpha C of one a.a. to the alpha amino group of another
• secondary=alpha and beta
• alpha=most common, all a.a. in chain form H bonds w/each other, 3.6 a.a. per turn
• beta=polypeptide chains running ll to each other connected via H bonds, can be ll or anit-ll
• supersecondary structure=motifs, B-alpha-B, B-meander, greek key
• tertiary=overall folding fo the entire chain into a specific 3D chain
• quaternary=describes the way in which the diff. subunits are packed together to form the overall structure of the protein

• partial double bond character
• trans and cis config.
• uncharged and polar

globular vs. fibrous

• globular=soluble
• hemoglobin, crystallins, insulin, enzymes
• fibrous=insoluble
• silk, collagen, elastin, alpha keratin

• protoporphyrin ring with an iron in middle

• heart and skeletal muscle
• fxn as a reservoir for oxygen and ain oxygen carrier
• has a higher oxygen affinity than hemoglobin
• disociation curve has a hyperbolic shape
• binds oxygen or it doesn't, reversibly binds a single oxygen

• red blood cells
• fxns to transport oxygen from lungs to capillaries and tissue and carry CO2 from tissue to lungs
• type A is main in adults, four polypeptide chains 2alpha and 2bet
• T form=tense, deoxy form, low oxygen affinity
• R form=relaxed, oxy form, high oxygen affinity
• disoc. curve has a sigmoidal shape, binds oxygen with increasing affinity

• decrease in pH=decrease oxygen affinity of hemoglobin=shift diss. curve to the right

• globular proteins found in lens
• serve a structural role
• Beta type is most common type in the lens

• oxidation>disulfide bonds b/n cysteine residues>aggregation & eventual cortical cataract formation
• glutathione is thought to protect crystallins from cross-linking by binding to exposed groups

• fibrous protein
• most abundant protein in body
• made up of 3 alpha chains that form a triple helix
• 8 major types of collagen
• 1=cornea and sclera
• 2=vetreous
• 4 & 8=descements
• 7=bowmans
• fibroblasts make collagen

• group of generalized CT disorders that are the result of defects in collagen
• characterized by stretchy skin and loose joints
• caused by a point mutation(adenine substituted for guanine which leads to glutamate for glycine)

• mutations in genes for procollagen
• blue-gray sclera, abnormal bone fragility, reduced stature

• abnormal fibrillin-1 (component of elastin fibers)
• tall stature, long arms and fingers, aortic dilation, subluxated lens

• make up the walls of blood vessels
• alpha-keratin=hair, nails, skin

• crystallins
• collagin
• mucous glycoproteins=proteins to which small chains of sugars are bound, ex. rhodopsin and mucins, found in precorneal tear film (mucins) where they maintain the stability of the PCTF
• mucin is secreted by goblet cells
• rhodopsin=membrane protein found in discs of rod outer segments
• VEGF

• inherited retinal degenerative disease of rods
• genetic defect
• leads to accumulation of metabolic by products that disrupt retinal fxn and leads to PR loss and RPE hyperplasia
• results in nyctalopia(night blindness) and loss of peripheral field

• involved in angiogenesis=making blood vessels from other ones
• vasodilator
• stimulates responses by binding to tyrosine kinase receptors (VEGFRs)
• this triggers a tyrosin kinase pthwy leading to angiogenesis
• may be upregulated in diabetes
• avastin is first FDA approved drug to inhibit angiogenesis, it is designed to bind to and inhibit VEGF, can be used in tx of wet AMD

• enzyme that breaks sucrose into glucose and fructose

• protein part of enzyme
• haloenzyme=apoenzyme + cofactor
• cofactors are metal ions

• catalyze redox rxns
• add or remove a proton

• catalyze transfer of C, N, or P containg groups
• kinases are specialized transferases that regulate metabolism by transfering phosphate from ATP to other molecules

• cleaves bonds by addition of water

• catalyze cleavage of C-C of C-S bonds

• catalyze racemization of optical isomers
• racemization=change an entity from one enantiomer to the other

• catalyze formation of bonds b/n C and O, S, and N
• catalyze rxns in which two chemical groups are joined with the use of energy from ATP

• slow the rate of a rxn
• 3 types
• competitive=competes with substrate at the active binding site, X pattern , no change in Vmax but Km is increased
• noncompetitive=acts at an adjacent site to the active binding site, V pattern, no change in Km but Vmax is decreased
• uncompetitive=inhibitor binds at a site distinctive from the active site, prallel lines, Vmax is reduced and Km changes

• enzyme of precornail tear film
• destroys gram positive bacteria via hydrolysis of glycan cell wall
• specifically breaks the beta 1-4 glycosidic bond
• measurement of lysozyme activity reflect the productivity of the main and accesory lacrimal glands (schirmer test 1 normal=19-30mm)

• plasma membrane enzyme
• responsible for cornel dehydration
• produces aqueous fluid
• located along sides of enodthelial cells
• controls deturgence=mechanism by which the cornea remains dehydrated and clear
• pumps NA out and water follows into ant. chamber

• enzyme responsible for converting pyruvate to form lactate
• found in cornearl epith., lens fiber cells, and PR cells
• operates at the jxn of aerobic and anairobic metabolism
• 3 types=H-heart, M-muscle, K-cancer and PR cells-high metabolic rate
• isoenzyme

• in aldoketoreductase family of enzymes
• fxn has been show to cause cataracts in people with diabetes
• globular
• first step in the polyol pthwy
• the polyols produce an osmotic imbalance in the lens fiber cells, causing them to swell and burst
• inactive until conc. of glucose or galactose increases

• involved in breakdown of EC matrix
• protein hydrolases
• zinc is required at active site to fxn
• has roles in axial lengthening, globe remodeling, and removes damaged proteins from damaged corneal cells
• when myopia is induced the digest scleral proteins so new proteins can be formed to restablish axial length
• weakens cornea when it helps it heal

• common cause of corneal dysfxn of SCL wearers

• together they destroy the ground substance of the cornea and other supporting structures composed of fibrin and elastin
• elastase=cleaves elastin, IgG and IgA
• alkaline protease=interferes with fibrin formation and will lyse fibrin

• biochemical indicators in MI (along with CK and LDH)
• myoglobin may be the earliest indicator of MI
• Troponin is highly specific and sensitive for acute MI, Troponin T is elevated longer than I

• salivary glands=lingual amylase=digests starch
• stomach=HCL=denatures protein
• pancreas=secretes proteolytic enzymes and lipases=degrades proteins and fats
• liver and gallbladder=deliver bile salts=emulsify fat globules which makes them easier to digest
• small intestine=amylase=main polymeric-carb digesting enzyme, secreted by pancreas, produces di and trisaccharides which are converted to mono.. by saccharidases

• conversion of monomers into a form that can be completely oxidized
• sugars=glucose>acetyl CoA
• a.a.=all are deaminated>NH2 is removed>may enter any stage
• fatty acids=converted to aceytl CoA, glycerol is also used

• complete oxidation of nutrients and production of ATP
• everything has been converted to acetyl CoA
• acetyl group is taken to citric acid cycle and is converted to CO2 and ATP

• absorbed directly by facilitated transport
• travel via portal vein to the liver for:
• -oxidation to CO2 and H20 for energy
• -storage as glycogen
• -conversion to triglyceride(fat)
• -release into general circulation as glucose

• glucose
• galactose
• mannose
• fructose

• maltose
• sucrose
• lactose

• stored as glycogen
• ocular storage=corneal epith. cells and retinal muller cells

• 1st step is to retain glucose=hexokinase
• later split glucose into 2 3-C subunits
• rate limiting step=convert fructose 6-phospahte to fructose 1.6-biphosphate via phosphofructokinase
• 4 ATP formed+2 consumed=2 net

• pyruvate is converted to lactate
• in aerobic pthwy pyruvate is converted to acetyl CoA in the mitochondria

• glucose is metabolyzed into CO2 and H20
• goal is energy
• NADH and FADH2 tranfer e- to the ETC which provides energy to form ATP
• 36-38 ATP formed

• glycogen synthasse is responsible for bringing glucose molecules together to synthesize glycogen>Glu-6-phosphate is isomerized to Glu-1-phosphate
• glycogen phophorylase then breaks down glycogen to create glucose to use by the body, this enzyme is inhibited by increase ATP or glu-6-phosphate

• method to metabolize glucose with no prod. of ATP
• pentose synthesis (ribose-5-phosphate from glu-6-phosphate)
• produces NADH, fatty acids, and detoxifies cells

• reduces ROS to GSSG (oxidized glutathione)
• removes H202

• biosynthesis of new glucose (not from glycogen)
• important for high demand tissues, retina and brain
• lacatate>glucose

glucagon

• is secreted in a "starved" state to stimulate gluconeogenesis in the liver
• release is inhibited in the fed state

• lactate from exercising muscles is circulated to the liver for gluconeogenesis
• liver releases resynthesized glucose for transport back to the muscle

DM

• most common disorder of endocrine system
• body can't metabolize carbs, proteins, or lipids appropriately
• charactierized by hyperglycemia
• 2 types

insulin

• directs glucose uptake, glycolysis, lipid synthesis, etc.
• insulin dependent tissues=muscle and adipose

• non enzymatic rxn
• normal range is 4-6%
• diabetes=6.5-7% or greater

• blindness is 25 times more likely
• cornea=nerve degeneration, defective epithelial BM, stromal swelling
• lens=polyol pthwy, generation of sorbitol
• retina=exudation, hemes, and maculare edema

• disorder resulting from lack of enzyme used to normally degrage GAG
• partially degraded GAGs deposit in tissues
• ocular effects on cornea, retina, optic nerve
• hurlers syndrome(muco... I)=affects cornea and optic nerve, cloudy cornea and white pale ON

• 8-1 in women
• all ocular complication stem from the increase in volume of the orbital tissues with the fixed bony orbit
• exophthalmos
• lid retraction
• lagophthalmos
• diplopia
• corneal exposure
• conj. injection and edema
• always bilateral but often asymmetrical

• fatty acids
• triaglycerols
• phospholipids
• isoprenoids=cholesterol, bile salts, steroid hormones, fat soluble vitamins (A,D,E,K)
• esters=waxes
• eicosanoids=prosaglandins, a.a.
• glycolipids

• short-med. chain FAs are partially soluble in water and long chain FAs are insoluble
• amphipathic
• unsaturation=double bonds, more=more membrane fluidity

• 3FA + glycerol
• stored in adipocytes
• large energy depot
• broken down by acetyl CoA to ATP

phospholipids

• glycerol backbone with 2FA and 1 polar head group(choline, serine, inositol)

• backbone of 5C units
• cholesterol is required for membrane synthesis, bile acid synth., and for prodxn of steroids

• post. mucin layer=goblet cells
• meddle aq.=lacrimal glands
• ant. lipid=meibomian glands (25 UL and 20 LL)
• 65% of meibomian secretion is some form of ester (30% cholesteryl esters and 35% wax esters)

• 20C unsaturated
• 3 goups=prostaglandins, leukotrienes, and thromboxanes