Biochem week 2

glycogenolysis

glycogen → glucose

enzyme: glycogen phosphorylase → a-1,4 bonds

glucagon

• hormone

• promotes glycogenolysis in liver

lectin

• protein that binds specific carbohydrates in their Carbohydrate Recognition Domain (CRD)

  • ex) selectin is a type of lectin involved in healing

glycosyltransferases

• enzyme

• makes glycosidic bonds btwn sugar and other molecules = glycoside

glycation

• no enzyme process

• spontaneous binding of sugars to proteins or lipids w/o enzyme involvement = advances gylcation end products (AGE)

dextran

• type of carbohydrate made by bacteria and dextransucrase

• functions as an extracellular network of dextrans called glycocalyx (sticks to teeth and causes caries)

blood type a

• antibodies against b

• donates: A/AB

• recieves:A/O

blood type B

• antigens against A

• donates: B/AB

• recieves: B/O

blood type AB

• has no antigens

• donates AB

• receives A/B/AB/O

blood type O

• antigens against A & B

• donates: A/B/AB/O

• receives: O

phosphatidylcholine

• type of lecithin [phospholipid. w/ a choline]

• most abundant

sphingolipids are derived from

ceramide

sphingomyelin

H=choline, what kind of sphingolipid?

cerebroside

H=glucose, what kind of sphingolipid?

ganglioside

R=oligosaccharide, what kind of sphingolipid?

cerebroside and ganglioside

2 types of glycolipids

pancreatic digestion steps in thee small intestine

1.emulsification

2.absorption

3.small ones excreted directly into blood stream

4.larger FA converted into triglycerides and are transported via chylomicrons

pathway that allows cholesterol to enter cells

receptor mediated endocytosis

what is nonfunctional in hypercholesterolemia?

LDL receptor
accumulation in LDL in bloodstream.

ketosis

when body burns fat instead of glucose

insulin

• secreted by pancreas

• fatty acids → triglycerides

epinephrine

• makes lipase enzyme

• triglycerides → fatty acids

• aids in ketogenesis

tay sachs disease

• improper functioning lysosomes in nerve and spinal chord

• leads to dementia

protein importing via nuclear pore

1. protein bound to importin when it recognizes signal

2. importin bring it thru pore

3. inside nucleus RAN GTP binds importin

4. RAN GTP takes it outside the nucleus

5. outside the nucleus RAN GAP separates RAN-Importin via dephorphorylation

protein importing thru mitochondria

1. protein signal sequence recognized by TOM

2. protein diffuses into intermemb. space and finds a TIM

3. as it goes thru both, the protein is unfolded

4. once inside the matrix, the signal sequence is cleaved by peptidase and a chaperone protein refolds it

protein importing into ER

1. free ribosomes translate a protein

2. signal sequence recognized by SRP

3. SRP brings it to membrane

4. protein continues to be printed thru the membrane into the ER

5. ribosome goes back once its done

protein importing via vesicles

1. rab protein is the vesicle’s ID

2. tethering protein lassos it in

3. t-snares (target) bind the v-snares(vesicle)

4. membranes fuse

5. cargo released

vesicle formation

1. clathirin (coat formation)

2. adaptin (link)

3. dynamin(pinch off neck and separate vesicle)

cystic fibrosis

1. chloride ion channel (cystic fibrosis transmembrane conductance regulator-CFTR) doesn’t work

2. normally thin slippery secretions are now thick mucous

vesicle exocytotic pathways

1. constitutive - ongoing flow from golgi to membrane

2. regulated - sits at membrane until signal received

Hutchinson-Gilford Progeria Syndrome

• little old people

• progerin production instead of pre-lamin A

• cells deteriorate faster bc nucleus doesn’t have support

Muscular Distrophy

• muscle nucleus deteriorates

• jaw changes shape

  • cant breathe, walk, swallow,

all 4 intermediate filament classes are located where?

the cytoplasm

what are the interm. fillament classes

1. lamins - nucleus

2. vimentin - skeletal muscle

3. keratin - epithelium

4. neurofilaments - neurons

Plectin

helps reinforce intermediate filaments

dynamic instability

• quality of microtubules

• GTP - dimer held tight

• GDP - chain disassembles

  • when target is not anchored

motor proteins

• kinesin + end

• dyenin - end

• head- MT

• tail- vesicle

• ATP - bound

• ADP - release and moves towards its polarity.

cell crawling

• lamellipodia - pushes cell

• filipodia - finger like projections

• integrins - link w ECM and actin

myosin 1 location

all cells

myosin 2 location

muscle cells

actin/myosin interaction

• myosin bind ATP and lets go of actin

• ATP → ADP; bind actin again

• myosin releases phosphate; power stroke

• myosin binds atp and repeat

tropomyosin/troponin

• regulators

• inactive muscle = binding sited covered

• nerve impulse → Ca release

• Ca binds troponin freeing tropomyosin from binding site for myosin

TMD treatment

botox

• acetylcholine not released from pre-synaptic cell

  • degrades v/t snares

MMPs

enzymes that cut through ECM —> arthritis

proteoglycans

cushions within the ECM

• GAGs that bind to water

tight junctions made of?

claudins and occludins

adherens junctions and desmosomes

• connect epithelial cells via cytoskeleton

• use cadherin

• interm filaments(desmosomes)

• actin(adherins)

Pemphigus Vulgaris

• defective desmosome

• lining falls apart = blisters & ulcers

hemidesmosome

connects epithelial to basal lamina

gap junctions

• openings btwn cells

• uses connexons