Biochem Test 2

Front 1

Phosphoglucomutase-

Back 1

Used in glycogen synthesis - first enzyme

Glc-6-P to Glc-1-P

Front 2

Where does glycogen synthesis take place?

Back 2

in the cytoplasm

Front 3

What is the structure of glycogen?

Back 3

mostly alpha 1,4 with every 12 an alpha 1,6

Front 4

UDP-Glc Pyrophosphorylase

Back 4

Used in glycogen synthesis - activates the glc

Front 5

What enzyme works with UDP-Glc pyrophosphorylase?

Back 5

inorganic pyrophosphatase ( PPi to 2 Pi) - makes the reaction irreversible and removes a toxic substance

Front 6

Glycogen Synthase-

Back 6

Used in glycogen synthesis -
makes alpha 1,4 bonds to terminal glucose only

Front 7

Branching enzyme0

Back 7

transfers 6-7 Glc onto the C-6 of another Glc - Making a alpha 1,6 bond

used in glycogen synthesis

Front 8

Phosphorylase-

Back 8

Used in glycogen breakdown
-removes Glc until 4 Glc remain in a chain
-uses phosphate to cleave producing Glc-1-P
-breaks alpha 1,4

Front 9

Phosphoglucomutase-

Back 9

Used in glycogen synthesis - first enzyme

Glc-6-P to Glc-1-P

Front 10

Debranching enzyme-

Back 10

Used in Glycogen breakdown
1- transfers a TRIsaccharide to other ends leaving behind 1 alpha1,6 glc
2-- removes tje alpha 1,6 Glc HYDROLITICALLY (leaves as free Glc)

Front 11

Where does glycogen synthesis take place?

Back 11

in the cytoplasm

Front 12

Where does glycogenolysis take place?

Back 12

In the cytoplasm -- both glycogen breakdown and formation takes place in the cytoplasm

Front 13

What is the effect of glucagon and epinephrine on Glycogen Synthase and Phosphorylase?

Back 13

Phosphorlates both - making Glycogen Synthesis inactive and Phosphorylase active

-Insulin dephosphorlates both -and has opposite effects

Front 14

How does epinephrine and glucagon have their effects?

Back 14

through signal transduction

Front 15

What is the primary regulation of glycogen metabolism?

Back 15

Hormonal control

Front 16

What are the key targets of epinephrine?

Back 16

Muscle and liver

Front 17

What is the purpose of epinephrine?

Back 17

prepares body for emergency - faster heart rate, heart output, and blood pressure (derived from tyrosine) - secreted by the adrenal medulla

Front 18

What is the target of glucagon?

Back 18

the liver ONLY - has a much longer duration of action

Front 19

What does the general action of insulin?

Back 19

activates phosphoproprotein phosphatases - leading to the dephosphorlation of proteins
-- stimulate glycogenesis

Front 20

Where are adrenergic receptors found?

Back 20

on the EXTERNAL side of the PM

Front 21

Where is adenylate cyclase found/?

Back 21

on the INTERNAL side of the PM

Front 22

What binds to adrenergic receptors?

Back 22

epinephrine in muscle and liver (key targets)

glucagon - liver only

Front 23

How many subunits does a G protein have? what does the alpha do?

Back 23

3 -
alpha - binds the GTP- and then goes to activate the adneylyl cyclase

Front 24

Adneylyl cyclase -

Back 24

ATP - cyclic AMP

Front 25

Describe the structure of cAMP.

Back 25

the elimination of PPi results in a closure of a six-membered ring involving the alpha phosphate groups. = the 3' and 5' hydroxyl groups of the ribose are esterified forming a phosphodiester

Front 26

What is the main function of cAMP?

Back 26

to activate PKA

Front 27

Where is PKA found?

Back 27

cytoplasm

Front 28

What is the general action of PKA?

Back 28

Phosphorlation - promotes glycogen breakdown
-makes glycogen synthesis inactive
--wiht Ca and Calmodulin makes Phosphorlase Kinase completely active

Front 29

Phosphorylase Kinase -

Back 29

Phosphorlates Phosphorlase B making it Phosphorylase A (active) - requires PKA and Ca and Calmodulin

Front 30

Why can only the liver regulate blood glc from glycogen breakdown?

Back 30

b/c it is the only place with Glc-6-Phosphatase

Front 31

Glc-6-Phosphatase-

Back 31

In liver only - Changes Glc-6-P to Glc

Front 32

Phosphodiesterase-

what inhibits it?

Back 32

cAMP back to 5' AMP (cleaves the 3')
--inhibited by methyl xanthines (tea and coffee) leading to higher blood glc

Front 33

How can we have 2 different allosteric regulators of phosphorylase? What are the 2 activators?

Back 33

2 separate genes

Front 34

What is the effect of G-6-P on phosphorylase in resting muscle during the well-fed state?

Back 34

Decreases its activity- can inactivate phosphorylase even when it is phosphorylated

Front 35

What allosterically effects phosphorylase B in hard working muscle?

Back 35

AMP - makes it more active

Front 36

What is the effect of Glc on phosphorylase in liver during the well-fed state?

Back 36

Decreases phosphorylase A activity and increases Synthase D which is normally inactive

Front 37

How many pairs of e- does Glc have to give up?

Back 37

12 pairs of e-

Front 38

How many pairs of e- are given up in Glycolysis? From Pyruvate?

Back 38

Glycolysis- 2 paris

Pyruvate - 5 pairs (2 pyruvate per 1 glucose molecule)

Front 39

Where is Pyr converted to AcCoA?

Back 39

Mito Matrix

Front 40

What is the PDH made of? name them

Back 40

3 different kinds of enzymes
-Pyruvate Decarboxylase
-Lipoyl transacetylase
-Dihydrolipoyl dehydrogenase

Front 41

What are the substrates used in the PDH complex?

Back 41

Pyrvuate, NAD, Coenzyme A

Products
Acetyl CoA, NADH, CO2

Front 42

How many coenzymes are in the PDH complex?

Back 42

5 different coenzymes

-Thiamine pyrophosphate, FAD, lipoic acid, coenzyme A, NAD+

Front 43

What is the purpose of the thiamine pyrophosphate in PDH?

Back 43

decarboxylation --w/o cant make Acetyl CoA

Front 44

Why is the PDH important to regulate?

Back 44

Because the reaction is irreversible

Front 45

What are the 2 ways to regulated PDH?

Back 45

1. Allosteric (AcCoA, NADH, ATP)
2. Phosphorylation - PDH KInase

Front 46

PDH phosphatase-

Back 46

Turns on PDH by dephosphorlation
-activated by Ca -released from hard working muscle

Front 47

What else can perform the same reaction as PDH Kinase? but doesnt--- whhy?

Back 47

PKA can run the reaction but doesnt because of location -
- PDH happens in matric - PKA is in cytoplasm

Front 48

Name 3 molecules that turn on PDH kinase

Back 48

1. AcCoA
2. NADA
3. ATP

PDH kinase -then turns off PDH

Front 49

What step of Krebs cycle is Isocitrate dehyrdogenase?

Back 49

4 - Produces CO2 and NADH
converts isocitrate to alpha keto glutarate

Front 50

Alpha ketogluatarate dehydrogenase-

Back 50

converts alpha ketoglutarate to succinyl CoA -- produces CO2 and NADH

Front 51

What substrate is the only substrate to produces GTP in the Kreb's cycle?

Back 51

Succinyl CoA

Front 52

How is isocitrate dehydrogenase regulated?

Back 52

Allosterically -Increased ATP and NADH decrease enzyme -which causes citrate to build up and inhibit PFK1
-still run glycolysis in

Front 53

What are the substrates where a coenyme is made in the Kreb's cycle?

Back 53

Isocitrate, alpha keto-glutarate, Succinate, malate

Front 54

What are the 2 ways to get cytoplasmic NADH into the matrix?

Back 54

The malate shuttle and Glycerol 3-P shuttle

Front 55

Cytosolic glycerol-3-phosphate dehydrogenase

Back 55

Converts NADH + H to NAD - used in the glycerol-3-phosphate shuttle

Front 56

Mitochondrial glycerol -3-phosphate dehydrogenase

Back 56

Changes glycerol-3-phosphate to dihydroxyacetone phosphate
-- And gives 2H to FAD forming FADH2 - which goes to UQ

Front 57

What can run gluconeogenisis

Back 57

Liver and Kidney (minor0

Front 58

What are 3 sources of C for gluconeogensis?

Back 58

Lac/Pyr
-Glycerol from FA
-Glcuogenic Amino Acids

Front 59

Name the glucogenic Amino acids.

Back 59

All except lysine and leucine

Front 60

How many ATP total do you make from glycolyisis when O2 is around?

Back 60

6 (4 from substrate level) - use 2 and 2 from cytoplasmic NADH

Front 61

How many enzymes are required for the Glycerol-3-P shuttle?

Back 61

2- one cytoplasic and 1 mitochrondial glycerol-3-phosphate dehydrogenase

Front 62

What are the bypass reactions in gluconeogeneiss?

Back 62

-pyruvate to PEP
-Fructose 1,6 bisphosphate to fructose-6-P
-Glucose-6-P to free glc

Front 63

What enzymes are required to change pyruvate to PEP? and where aer they located

Back 63

- Pyruvate Carboxylase -mito
-PEP Carboxykinase -cyto

Front 64

Pyruvate Carboxylase-

Back 64

Pyrvate to PEP
-Requires CO2, ATP, ACoA, and Biotin to work

AcCoA - a obligate activator of pyruvate carboxlyase

Front 65

What happens to OAA that is formed in gluconeogenesis?

Back 65

Has to be coverted to malate by using NADH to NAD because it cant get out of the mitochondria. In cytoplasm it is reconverted to OAA bu using NAD+ to NADH

Front 66

PEP Carboxykinase- PEP=CK

Back 66

OAA + GTP to PEP +GDP + CO2

Front 67

What regulates PEP=CK

Back 67

Glucagon and cortisol - both increase the gene expression of pep-ck

Front 68

What is the energy used for the make PEP?

Back 68

1 ATP used in the mito - to add a CO2
1 GTP used in the cytoplasm to remove CO2
-makes the rxn irreversible bc now can blow off the CO2

Front 69

Fructose 1,6 Phosphate bisphosphatase-

Back 69

F1,6 bisphosphate to Fructose 6 Phosphate + Pi

-used in gluconeogenesis

Front 70

What are the allosteric regulator of F1,6 P bisphosphatse?

Back 70

-used in gluconeogenesis
-F2,6 P a negative regulator
ATP -positive regulator

Front 71

Where is glc-6-P found?

Back 71

in liver and kidney -why they are the only places you can run gluconeogensis

Front 72

Where is the energy coming from to run gluconeogenisis?

Back 72

ATP from TG mobilization and FA beta oxidation

Front 73

Why are the 18 AA glucogenic?

Back 73

Becuase they can be changed into alainine which can be changed into pyruvate

Front 74

What step of gluconeogenesis requires NADH?

Back 74

1,3 bisphosphoglycerate to Glyceraldehyde-3-P

Front 75

How many high energy phosphate bonds does it take to make Glc from Pyr?

Back 75

6 --- 4 ATP, 2 GTP

and 2 NADH

Front 76

When FA beta oxidation is running what is also running?

Back 76

Gluconeogenesis - because FA Beta oxidation makes a lot of AcCoA --- a lot of AcCoA -positive regulator or pyruvate carboxylase

Front 77

For how long can the liver regulate blood glucose levels with glycogen?

Back 77

12 hours -then gluconeogenesis must fully be kicked in

Front 78

Why does glycogenolysis and gluconeogenesis occur at the same time?

Back 78

Bc gluconeogenesis is turned on at the genetic level - takes several hours - need to go ahead and turn it on so you will have it later

Front 79

What 2 enzymes does cortisol and glucagon up regulate?

Back 79

PEP-CK and F1,6 bisphosphase

Front 80

What is the direction of electron flow in the ETC?

Back 80

- A decreasing potential energy and increasing reduction potential

Front 81

What is the difference between the 2 different types of Flavoproteins?

Back 81

-Pyridine nucleotides (NAD)
--reversibily associated with enzyme

-Flavin nucleotides
--tightlyor covalently linked to enzyme (never leave the enzyme)

Front 82

What are FeS proteins?

Back 82

the iron is not present in the heme but in association of the S atoms or with the S of Cys in proteins.

-these FeS proteins participate in 1 e- transfer in which Fe is oxidized and reduced (can go either way)

Front 83

What is the entry point for e- from flavoproteins/

Back 83

Coenzyme Q (ubiquinone) -a lipid

Front 84

What is the only ETC component not associated with proteins?

Back 84

Coenzyme Q - a lipid

Front 85

What is coenzyme Q's structure similar to?

Back 85

Vit E and K

Front 86

cytochromes-

Back 86

electron transfer proteins that contain a heme group tightly or covalently bound -- distinguished by their respective light absorption spectra

Front 87

WHat is the number of ATP equivalents during the conversion of pyruvate to glucose in gluconeogenesis?

Back 87

-10

Front 88

What is the ETC made of?

Back 88

4 enzyme complexes
2 mobile carriers

Front 89

What is the only substrate in Krebs that can create FADH2? Where is the enzyme located?

Back 89

Succinate -- located on complex 2 in ETC

Front 90

If the ETC is inhibited what is the form of carriers before that point and after?

Back 90

Before - fully reduced

after - fully oxidized

Front 91

What does barbituates or rotenone inhibit?

Back 91

Block NADH going to CoQ (inhibits complex 1)

Front 92

What does cyanide or CO inhibit in the ETC ?

Back 92

CN- bind to Fe3+ in complex IV (CO binds to Fe2+)
- bind to the complex 4 and doesnt allow the e- transport to happen
--cant move the e- from cytochrome aa3 to O2

Front 93

What is a bad sideeffect of nitroprosside - a antihypertension drug?

Back 93

Cyanide can be produced

Front 94

Describe the best treatment for Cyanide Posioning

Back 94

Give an nitrite oxidant to form Hb(Fe3+) from HbFe2+. CN- will bind to the HbFe3+ instead of the one in the ETC. HbFe3+ competes with cyto aa3 for CN-

Front 95

What is the bad treatment cyanide posioning?

Back 95

Giving a thiosulfate --that creates thiocyanate which is still toxic -but less toxic - works quickly

Front 96

What is the treatment for CO posioning that interferes with ETC?

Back 96

give 100% O2

Front 97

What is the only enzyme of the Citric Acid Cycle that is not in the matrix?

Back 97

The succinate to fumarate -- located on the inner mitochondrial membrane

Front 98

What complex passes e- only and no H+ to the inner membrane space?

Back 98

Complex 2

Front 99

What are the 2 major components of ATP synthase?

Back 99

F1- ATP synthase
F0- channel for protons

Front 100

What parts of ETC requires H+ to balance the charge and what parts dont?

Back 100

Require H+ - CoQ

Dont require - Complex 1,2,3

Front 101

What are the 3 requirements for oxidative phosphorylation?

Back 101

1. Components are membrane bound
2. Electron transport
3. proton gradient

Front 102

How does ATP get out of the matrix after formed?

Back 102

--Adenosine nucleotide translocase transporter (antiporter) --moves ATP into the intermembrane space and ADP into matrix

Front 103

How does the phosphate needed to make ATP from ADP get into the matrix?

Back 103

Through the phosphate translocase (a symporter)
Moves both H+ and H2PO4- into the matrix from the intermembrane space

Front 104

What is the proton motive force responsible for?

Back 104

1. providing energy for ATP syntheses
2. transporting the substrates needed in (ADP and Pi) and products (ATP)out of the matrix

Front 105

What does Atractyloside does?

Back 105

A plant substance that inhibits ATP-ADP translocase --decreasing oxidative phosphorylation

Front 106

Respiratory Control-

Back 106

Electon transport is tightly coupled to phosphorylation
-Electrons typically wont flow unless ATP is being made
--All controlled by ADP

Front 107

What controls how fast the ETC goes?

Back 107

ADP -- when ATP is consumed it increases ADP which increases ETC

Front 108

Oligomycin-

Back 108

A toxic macrolide - blocks the entry of H+ into the Fo channel
-Decreases the pH in cytoplasm and e- flow stops

Front 109

What are uncouplers?

Back 109

All the energy goes to heat and none going to making ATP instead of 50/50
-molecules which dissociate oxidation in the ETC from phosphorylation
-why viruses cause fevers

Front 110

Dinitrophenol-

Back 110

A weak acid and lipid soluble
-Destroys the pH gradient by shuttling H back inside the matrix
-no pH gradient but e- still flow - will not make ATP

Front 111

Why do you sweat when you exercise?

Back 111

You have more ADP - run ETC faster - producing 50% heat and 50% ATP

Front 112

Why do you hyperventilate with a fever?

Back 112

A fever = an uncoupler (not making any ATP)

You are running ETC faster - so you need more O2 as an e- acceptor

Front 113

Brown fat- purpose?

Back 113

generate heat to keep a newborn warm - found in the back of the neck
-brown due to large numbers of mito and thus cytochromes

Front 114

How does brown fat work?

Back 114

Has a uncoupling protein channel -thermogenin- this allows H+ to pass either through the ATP synthase or through thermogenin - so a higher proportion is converted to heat

Front 115

What activates thermogenin?

Back 115

FA

Front 116

What is creatine used for?

Back 116

A storage source of ATP - can go to create Creatine-P which can be converted back to ATP

Front 117

Creatine Kinase-

Back 117

takes Creatine and ATP to form creatine-P and ADP or the reverse

- forms a storage source of ATP

Front 118

Where are the 3 different types of creatine kinase found?

Back 118

MM- skeletal muscle
BB- brain
MB and MM - cardiac

Front 119

How does creatine kinase tell you if you have had an MI?

Back 119

If you find MB in the blood = MI

Front 120

Why is creatine phosphate rare?

Back 120

Very unstable -- has a P bonded to a N
-because it is so unstable it will spontaneously create creatinine which is deadend and then we excrete through urine

Front 121

Why does creatine make muscles look bigger?

Back 121

It goes into the muscles and its osmotic - so increases the size bc of H20

Front 122

When sprinting for 10s why doesnt your ATP levels drop?

Back 122

3 ways to produce more ATP-
-combine 2 ADP to make AMP and ATP
-use the creatine phosphate storage
-anaerobic glycolysis to form 2 ATP

Front 123

What does AMP activate?

Back 123

Phosphorlase B to phosphorlase A

activates PFK-1

Front 124

When sprinting if you can keep your ATP levels up -why do you slow down?

Back 124

Because of the build up of lactic acid

Front 125

When exercising what do you do when the glycogen is gone?

Back 125

you use FA metabolism - which is aerobic