12/8 Lecture

Front 1

Acetyl CoA is completely oxidized to___ by the citric acid cycle. the energy is produced inthe form of reduced e- carriers ____

Back 1

Co2

NADH and FADH2

Front 2

Pyruvate, the product of glycolysis, is converted to acetyl CoA + CO2 by ____; reaction is irreversible

Back 2

pyruvate dehydrogenase (PDH) complex

Front 3

PDH complex is made up of three enzymes

Back 3

Pyruvate Dehydrogenase (E1)

Dihydrolipoyl transacetylase E2

dihydrolipoyl dehydrogenase E3

Front 4

Thiamine pyrophosphate (TPP) is attached to what enzyme of the PDH

Back 4

E1- catalytic cofactor

Front 5

Lipoate is attached to what PDH enzyme

Back 5

E2- "swinging arm"

Front 6

FAD is attached to what PDH enzyme

Back 6

E3- serves as an e- carrier

Front 7

Coenzyme A is an acyl carrier, in PDH and contains a reactive ___ that forms ___ with acetate in acetyl coA

Back 7

thiol group (-SH)

thioester

Front 8

Lipoate has two ___ that undergo reversible oxidation to a ____. It can sere as both a e- carrier and an acyl carrier

Back 8

thiol

disulfide bonds

Front 9

lipoate in amide linkage with a lys residue forms a ___ .

Back 9

swinging arm

Front 10

E1 (pyruvate dehydrogenase) provides the ____ step converting phyruvate to hydroxyethyl TPP;

Back 10

decarboxylation

Front 11

Lipoamide provides the swinging arm that transfers the product of E1 (hydroxyethly) to the active site of ____ where it is oxidized to the acetyl group and transferred to ____,

Back 11

E2

CoA-SH

Front 12

E2 (dihydrolipoyl transsacetylase) oxidizes hydroxyethyl TPP to acetyle and two e- which is used to reduce the ____ of lipomide. The acetyl is now ____ to the SH and E2; the acetyl is then esterfied (and transferred) to the Sh of CoA to form acetyl CoA

Back 12

disulfide bond

esterfied

Front 13

dietary thiamine deficiency can have sever consquences resulted from inability to oxidize pyruvate normally, leading to ___ disease which is characterized by the loss of neural function, severe lethargy, fatigue, muscle pain, psychosis, heart failure

Back 13

Beriberi

Front 14

citrate synthase

Back 14

aldole condensation of acetyl coA with oxaloacetate to form citroyl coA intermediate which is hydrolyzed to form citrate (and Coa)

delta G= -32.2

Front 15

aconitase

Back 15

Citrate-> cis aconitate (intermediate) -> isocitrate

Dehydration -hydration rxn- to change location of OH on cirtate/ moves it down

Front 16

isocitrate dehydrogenase (regulating step)

Back 16

Isocitrate +NAD -> alpha ketoglutarate +Co2 +NADH

first oxidation reaction;

two forms, mito version uses NAD while cytolic enzyme uses NADP

-20.9 , important regulatory step

Front 17

alpha ketoglutarate dehydrogenase complex (regulating step)

Back 17

alpha ketoglutarate + CoA-SH +NAD-> Succinyl coA + CO2 + NADH

oxidative decarboxilation- second oxidation

transfers e- to NAD and CoA serves as succynil group carrier

-33.5, important regulatory step

Front 18

succinyl-CoA synthetase

Back 18

succinyl-CoA + GDP -> Succinate +GTP + CoA-SH

substrate level phosphorylation- only phosphorylation step in cycle ; produces GTP

reversible

Front 19

succinate dehydrogenase

Back 19

succinate + FAD -> fumarate + FADH2

dehydrogenation/ oxidation - 3rd oxidation

enzyme bound to inner mitochondrial membrane and is directly linked to e- transfer chain

reaction at equilibirum so G= 0

Front 20

fumarase

Back 20

Fumarate + H20 -> L Malate

hydration across the double bond

reverisble

Front 21

malate dehydrogenase

Back 21

L malate + NAD ->Oxaloacetate + NADH

oxidative dehydrogenation- 4th oxidation reaction

low concentrations of oxaloacetate drives reaction

Front 22

the energy released by oxidations is conserved in 3___ and 1 ___ and ___ GTP is produced

Back 22

NADH

FADH2

1

Front 23

the citric acid pathway is an ____, serving in both catabolic and anabolic processes

Back 23

amphibolic pathway

Front 24

CAC provides precursors for many biosynthetic pathways -

citrate->

alpha ketoglutarate ->

Succinyl-CoA ->

Oxaloacetate ->

Back 24

-Fatty acids / steriods

- glutamate

- porphyrins, heme

- PEP to enter become glucose, or become AA

Front 25

when intermediates of the CAC are shunted from the cycle to other pathways, they are replenished by several ____ reactions

Back 25

anaplerotic ; pyruvate can be converted to oxaloacetate via pyruvate carboxylase ; PEP can be converted into oxaloacetate via PEP carboxykinase ; pyruvate can be made into malate via malic enzyme

Front 26

Anaplerotic reactions produce 4 C intermediates by ___ of 3 carbon compounds

Back 26

carboxylation

Front 27

pyruvate carboxylase converts Pyruvate into ___ in the liver and kidney ; the most important anaplerotic reaction

Back 27

oxaloacetate ; consumes ATP

Front 28

PDH complex is inhibited by: stimulated by:

Back 28

inhibited- ATP, acetyl Co-A, NADH, fatty acids- high energy states

stimulated- AMP, CoA, NAD, Ca

Front 29

citrate synthase is regulated by

Back 29

inhibited- ATP, NADH, succinyl-CoA, citrate, (high energy state and feedback inhibition)

stimulated- ADP

Front 30

isocitrate dehydrogenase is regulated by

Back 30

inhibited by- ATP (energy state)

stimulated - Ca, ADP

Front 31

alpha ketoglutarate dehydrogenase is regulated by

Back 31

inhibition- succinyl-CoA, NADH

stimulation- Ca

Front 32

Glucose is converted to polymeric forms for storage, such as ____

Back 32

glycogen and starch

Front 33

in vertebrates, glycogen is stored mainly in the ___ and ___

Back 33

liver and skeletal muscle

Front 34

glycogen is found as___ in hepatocyes, which are complex aggregates of glycogen and the enzymes that degrade it

Back 34

granules

Front 35

Alpha rosettes

Back 35

cluster of 20-40 beta particles

Front 36

beta particles

Back 36

the elementary glycogen particle, consits of up to 55,000 glucose residues with about 2000 non reducing ends

Front 37

muscle glycogen serves as ____ while liver glycogen serves as ____

Back 37

quick source of energy

reservoir of glucose for other tissues

Front 38

degradation of stored glycogen to G6P is carried out by 3 enzymes

Back 38

glycogen phophorylase

glycogen debranching enzyme

phosphoglucomutase

Front 39

Glycogen phosphorylase

Back 39

catalyses removal of terminal glucose residues by phosphorlytic cleavage until it reaches the 4th glucose from an alpha 1-6 branch point

Front 40

debranching enzyme

Back 40

glucotransferase activity- shifts a block of 3 residues from a branch to a nearby non reducing end and reattached in a alpha 1-4 linkage

glucosidase activity- removes the single branching residue at the branch site (allows for continuation of glycogen phosphorylase action)

Front 41

Phosphoglucomutase

Back 41

converts G1P to G6P via donating a phosphoryl group to G1P at C6 and removing the group from C1

Front 42

glycogen synthesis (glycogenesis) takes place in almost all animal tissues but especially prominant in ___ and ___

Back 42

liver and skeletal muscles

Front 43

starting point for sythesis of glycogen is G6P which can be derived from free glucose in a reaction catalyzed by ___

Back 43

hexokinase

Front 44

phosphoglucomutase

Back 44

G6P -> G1P

Front 45

UPD glucose pyrophosphorylase

Back 45

G1P + UTP -> UPD glucose + Pi

Front 46

glycogen synthase

Back 46

elongation of glycogen chain with alpha 1-4 linkages to the non reducing end

transfers of glucose from UDP-glucose to a non-reducing end

Front 47

glycogenin

Back 47

serves as a primer on which new glycogen chains are assembled and as th enzyme that catalyzes the assembly

contains glucotransferase and chain extending activity

remains buried within the particle

Front 48

glycogen branching enzyme

Back 48

cuts a terminal fragment of 6-7 glucose residues and transfers them to the C6 hydroxyl group of an internal glucose reside

Front 49

the biological effect of branching is to make glycogen molecule more ____ and to increase the number of____

Back 49

soluble

nonreducing ends

Front 50

glycogen phosphorylase and glycogen synthase are reciporocally regulated by (2)

Back 50

allosteric affectors

reversible phosphorylation which is responsive to hormones

Front 51

the active (a) to inactive (b) form interconversion occurs via phosphorylation of phosphoylase by ___ ; the inactive form is made by dephosphorylation by ___

Back 51

PKB

PP1 (phosphorylase phosphate 1)

Front 52

In the muscles, Phosphoylation is triggered by ___ which activates PKB indirectly via hormonal regulation; ___ and ___ also activates PKB and thus phosphorylase a via allosteric regulation .

Back 52

epinephrine

Ca, AMP

Front 53

in the liver, ____ triggers activation of PKB and thus phosphoylase a; ____will inactive the enzyme by binding to an allosertic site.

Back 53

glucagon

glucose

Front 54

Glucose binding to an ____ of phosphoylase a induces a conformational change that exposes its ____residues to the action of phosphoylase a phosphatase (PP1) which converts the active form to the less active b form by dephosphoylation

Back 54

allosteric site

Ser

Front 55

___ also acts indirectly to stimulate PP1 and slow glycogen breakdown

Back 55

Insulin

Front 56

____ of epinephrine and glucagon action allows for large amplification of the initial signal

Back 56

cascade mechansim

cAMP /PKA/PKA/ glycogen phosporylase a

Front 57

glycogen synthase is inactivated by phosphorylation with ____, which acts only after phosphoylation of glycogen synthase by CKII (priming),

Back 57

glycogen synthase kinase 1 (GSK3)

Front 58

activation of glycogen synthase b occurs by dephosphorylation with ___

Back 58

PP1

Front 59

____triggers activation of glycogen synthase by blocking GSK3 and stimulating PP1; glucagon and epinephrine trigger inhibition of PPI

Back 59

Insulin

Front 60

deficiency in G6Pase (conversts G6P to glucose in liver)

Back 60

type 1 a; von Gierke's disease

Front 61

defciency in debranching enzyme

Back 61

type III; cori's disease; milder symptoms thatn von Gierke's

Front 62

deficinecy in branching enzyme

Back 62

type IV; andersen's disease

very long unbranced chains= large glycogen starge and enlarged liver

Front 63

deficiency in muscle glycogen phosphorylase

Back 63

type V; McArdle's disease

liver type is normal