BIOL 311 Exam 3

What was de Duve’s discovery & experiment?

Lysosomes through differential gradient centrifugation

Lysosome

• 50+ hydrolytic enzymes

• Single membrane bound (acid phosphate marker enzyme)

• pH 5

Two theories on white blood cells (example of heterophagy)

Virchow - WBC give birth to RBC (red blood cells)

Metchnikoff - Phagocytosis, WBC engulf RBC, disease prevention

Opsinization

Antibodies covering the surface of bacteria

Mysathenia Gravis

Autoimmune Disease, acetylcholine synapse

Too little Ach released OR problem with Ach receptor
Lysosomes degrade Ach more than it is synthesized

Mysathenia Gravis Drugs

1. Curare - Ach receptor antagonist → up MG symptoms

2. Eserine - inhibits Ach → Ach breakdown → up Ach down MG symptoms (Neostigmine and Predrisolone)

3. 3H-humgarotoxin - binds to Ach receptor

Autophagy

• Mitochondria & SER

• LC3 mediates

• Chloroquine & cisplatin (blocks DNA repair)

Environmental Lysosomal Diseases

Silicosis (silica into lyso, lyso enzymes leak, down elasticity & CO2/O2 exchange)

Chloroquine Myopathy/Retinopathy

Tay-Sachs Disease

Lacking Hex A, neurological, accumulation of ganglioside GM2

Hurler Syndrome/Mucopolysaccharidosis Type 1

• Large lysosomes → gangliosides accumulate

• alpha-L iduronidase defect

• Hurler & normal cell experiment

• Aldurazyme ERT treatment

I-Cell Disease

• No MGP tag

• Lysosomal enzymes & proteins don’t go to lysosomes

• Excess hydrolases in ECM

Guacker Disease

Cerezyme ERT treatmentP

Pompe Disease

Acid t-glucosinase defect

Myozyme ERT treatment

Proteasomes

• Only degrade proteins

• Ubiquitanated

• Velcade - inhibit proteasomes, cancer treatment

mitDNA

37 genes, 16,500 bases, circular, no corrections
Most mit proteins from nuclear genome

Location of mitochondria

Polarized epidermal cells, apical region, where ATP is needed

Colchicine

blocks microtubules

Why did the mitochondria lose most of its genes?

Most mitDNA proteins are hydrophobic and mitDNA proteins require local regulation

Outer mitochondrial membrane

fewer proteins, porins, voltage dependent anion channels (Ca2+)

Inner mitochondrial membrane

oxidative phosphorylation, electron transport chain, cardiolipin (glue for ETC intermediates)

Mitochondria can move on microtubules (true/false)

true

How do the mitochondria induce apoptosis?

MPTP opens from cell stress, releases cytochrome C, activates caspase 9 (death receptor), caspase 9 + procaspase 3 → caspase 3 (executioner enzyme), apoptosis

Cycloaporin A

Inhibits MPTP opening

bcl-2

B cell lymphoma, makes cancers resistant to chemo when overexpressed

Why can we not use hep G2 for drug testing and how can they be modified to be effective?

Hep G2 does not react to drugs the same way normal heptocytes do, it reacts close to how heptocytes do when combined with gal

Warburg Effect

Down O2, cancerous, ATP from glycolysis not mitochondria

Mitochondrial Myopathies

mit diseases, exercise intolerance, myoclonus epilepsy, inherited, brain or muscle issues

Glycolysis

NADH → mitochondria → ATP, uses ATP, malate-aspartate

Chemiosmotic Hypothesis Experiment

Create inside-out sub mitochondria, manipulate with DNP (down ATP, H+ gradient) and GRAM (Vm). Vm has a greater impact

ETC (electron transport chain) inhibitors

Cyanide, CO, Rotenore

Uncouplers

Inhibit protein synthesis

GRAM, Valin, DNP, Olimycin

What drug compromises the H+ gradient?

DNP, a weak lipid soluble acid, H+ ionophone

What drugs are K+ ionophones that decrease the change in Vm?

GRAM - faster, channels

Valin - slower, mobile

What happens when you treat an inside-out sub mitochondria with olimycin?

FOFl particle is removed and ATP is not produced

Joseph Priestly suggested what

The existence of photosynthesis

Engelman found

Spinogyna - ribbon chloroplasts

Isolated chloroplasts

Robert Hill and Cornelius Van Neil found

O2 comes from H2O, without light bateria move away from O2 instead of aggregating

Why are cynabacteria significant

They produce more energy than they need, are simple prokaryotes, and have been sequenced

Carotene

Carcinogen, antioxidant, failed clinical trial cause it increased the risk of cancer

Photoinhibition

plant mech to protect against too much light (PSII more sensitive, P-D1 high turnover)

Rubisco

• low affinity for CO2, high abundance

• most plentiful protein

• C fixtation (up CO2 down O2)

• Photorespiration (down CO2 up O2)

Functions of ECM

1. Connect and identify cells/some tissues

2. Receptor mediation

3. Filter/matrix/barrier = basal lamina

What type of media do epidermal cells require

Microporous cell culture insert with Type 1 collagen cross linked with aldehyde and soaked with FCS

What media to human embryonic stem cells (hESC) require

Special ECM, irradiated mouse fibroblasts and no feeder layer

Homophilic cell adhesion molecule

CAM that binds to an identical CAM

Experiment proving cells recognize other cells

Liver and retina cells removed and grown in culture, retina cells will not bond to liver cells

Cadherins

homophilic, Ca2+, in all substrate dependent cells

IG Superfamily

neural CAM, retinal ganglion connections, embryonic n-CAM are glycosylated (PSA → slide around)

Basal Lamina

sheet like barrier, ECM

Loose Connective Tissue

ECM, porous, hydrated, fibroblasts, collagen and elastin, longest half life

Cornea

loose connective tissue, stroma (highly ordered collagen), descemet’s membrane (basal lamina), cataracts from stroma out of alignment and death of cornea endothelial cells

Collagen

insoluble in aqueous, fibrous, glycine every 3, triple helix, resist stretching

Glycine

smallest R group, needed for a helical structure, base

Scurvy

disease, lack vit C, no collagen around arteries

Collagen synthesis requires

RER for proline hydroxylation and lysl oxidase & O2 for final step

Glycosaminoglycans

Repeating disaccharides, many neg groups, sliding surface for cells, rigid

Glycosaminoglycans Treatments

Hyaluronan - cosmetic surgery, CD44 receptors

SynVisc One - knee osteoarthritis

Protoglycans

• Glycosaminoglycans + Proteins

• Bind growth factors to RTK’s & Fibromycin to ECM

• Syndecan 1

Fibronectin

• Not present in cancer

• multiadhesive, sticks cells in place

• dimer, morphogenesis

Laminin

• multiadhesive, in basal lamina

• Encourages neuronal phenotype

• trimer, self assembling

Integrin Receptors

• Low affinity high abundance (changes based on stucture)

• cross-talk

• Mg2+

• F-actin

RGD Sequence

binds integrins to ECM, fibronectin, without it cells Anoikis (apoptosis from not having a home)

LAD

leukocyte adhesion deficiency, Beta 2 integrin receptor, low extravasation (leukocytes → blood stream)

Duchenne Muscular Dystrophy

males only, skeletal muscle, laminin, dystrophin

Ehler-Danlos Syndrome

hypermobility (chronic joint pain) or classical (fragile skin), heterogeneous

Osteogenesis Imperfecta

collagen:

1. Type I norm structure low abundance

2. Type 2 no helix in collagen