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Biochemistry > Week 8 - Unit 2 > Flashcards

Week 8 - Unit 2 Flashcards

1
Q

What is the fate of glucose after a meal?

A
  1. Oxidized for energy in Glycolysis
  2. Synthesis of many compounds
  3. Storage as Glycogen or Triglycerides
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2
Q

What is the fate of Amino acids after a meal ?

A
  1. Protein synthesis
  2. Oxidation for energy
  3. Synthesis of nitrogen-containing compounds (nucleotides)
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3
Q

What is the fate of Fats after a meal?

A
  1. Storage- triglycerides
  2. Oxidation for energy
  3. Synthesis of membrane lipids
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4
Q

What are the dietary fuels?

A

Carbohydrates
Fat
Protein

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5
Q

Insulin will initiate cascade of events , anabolic processes of _______ fuels , and _____.

A

Storing

Growing

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6
Q

As levels of blood fuels decreases, you will see elevated levels of stress hormones ___, _____, and ______.

A

Cortisol
Glucagon
Epinephrine

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7
Q

The primary role of Cortisol, Glucagon, and Epinephrine is to initiate _____ processes to maintain a pool of fuel for cell functioning.

A

Catabolic - break down of stored fuels to release into bloodstream

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8
Q

Glucose is taken up by the Beta- cell in the pancreas via the _______ transporter. It is then ____ and increases levels of _____.

A

Glut-2 transporter

Oxidized

ATP

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9
Q

Increased levels of ATP in the Beta-Cells of pancreas (caused by Glucose entering cell), will cause the _____ ____ to close, causing decrease in the voltage in the cell, then opening the _____ channel.

A

Potassium channel

Calcium channel

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10
Q

Increase in calcium in Beta-cell will facilitate the packaging of _______ and the movement of it in _______ so it can be delivered to peripheral tissues.

A

Insulin (endocrine hormone)

Exocytosis

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11
Q

Insulin is initially translated as a _______ and requires cleavage of the _____ before it is active polypeptide.

A

Pro-protein

C-Peptide (2 cleavage locations)

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12
Q

The insulin protein, after the C-peptide is cleaved , consists of an ____ chain and a ____ chain that is linked by _____ linkages.

A

Alpha

Beta

Disulfide

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13
Q

What does Insulin bind in the target cells ?

what does it initiate ?

A

Tyrosine-kinase family

Initiates MAP-kinase cascade

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14
Q

when glucose is taken up by the liver, insulin will activate ______ production, fatty acid _____ and increase protein _____.

A

Glycogen

Synthesis

Synthesis

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15
Q

What will glucose paired with insulin activate in the skeletal muscle ?

A

Glycogen synthesis

Protein synthesis

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16
Q

What can high levels of insulin caused by blood glucose do in the adipocytes?

A

Synthesis of Triglycerides

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17
Q

When we synthesis Triglycerides or Glycogen we will at the same time ____ release of free fatty acids or release of free glucose.

A

Inhibit

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18
Q

When blood glucose is low what two main regions are stimulated?

A
  1. Brain- Hypothalamic regulatory center

2. Alpha cells of pancreas (release glucagon)

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19
Q

The pituitary gland in the hypothalamic regulatory center will secrete _______ during low blood glucose levels.

A

Adrenocorticotropic hormone (ACTH)

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20
Q

What does ACTH stand for ?

A

Adrenocorticotropic hormone

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21
Q

What does ACTH act on ?

A

Adrenal gland

  • activates cortex (Cortisol release)
  • activates medulla (Epinephrine release)
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22
Q

Where does Cortisol get released from ?

A

Adrenal gland Cortex

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23
Q

Where does Epinephrine get released from ?

A

Adrenal gland - Medulla

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24
Q

Glucagon binds a _____ receptor and then activates ______ as its second messenger.

A

G-coupled protein

cyclic AMP

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25
Q

The cAMP in the Glucagon cascade will activate ____ ____ A and elicit a cellular response.

A

Protein Kinase A

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26
Q

What do high levels of glucagon do to liver?

A

Glycogenolysis - catabolism of glycogen to free glucose

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27
Q

What do high levels of Cortisol do to the Skeletal muscle ?

A

Stimulate Protein catabolism so that AA can be delivered to Liver for gluconeogenesis to make more glucose

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28
Q

What does epinephrine do to the adipocytes?

A

Activates enzyme so that free fatty acids are released

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29
Q

What is the difference between Epinephrine and Norepinephrine at the chemical level?

A

-epinephrine has a Methyl group attached to its amine group, norepinephrine does not

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30
Q

Epinephrine will stimulate glycogenolysis in the skeletal muscle during exercise breaking it down to ______ to then make either acetyl CoA or Lactate depending on aerobic or anaerobic exercise.

A

Glucose

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31
Q

The primary responsibility of the liver is to provide _____ so the brain always has energy.

A

Glucose

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32
Q

The adipocyte will catabolize fat, and the fatty acids can be used in Skeletal muscle to make ATP or sent to liver who will make it into _____ ____ that can be used for energy by the brain.

A

Ketone bodies

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33
Q

In high blood glucose conditions, with insulin present , the liver is completing what functions

A
  1. Triglyceride synthesis
  2. Glycogen synthesis
  3. Active glycolysis
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34
Q

In low blood glucose conditions, the liver is completing what functions?

A
  1. Glycogen degradation
  2. Gluconeogenesis
    (Glucagon and Epinephrine are present and glucose is released ) -Catabolic
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35
Q

Dietary fats are packaged into _______ that consist of fatty acids and glycerol after absorption in the GI and can be stored in Adipose tissue.

A

Chylomicrons

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36
Q

What functions to promote fuel storage after a meal and promotes growth?

A

Insulin

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37
Q

What activates gluconeogenesis and glycogenolysis (liver) during fasting and activates fatty acid release from adipose tissue ?

A

Glucagon (mobilizes fuels)

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38
Q

What will mobilize fuel during acute stress ?

A

Epinephrine

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39
Q

What will provide for changing requirements over the long term (steroid hormone)?

A

Cortisol

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40
Q

Where does digestion begin ?

A

In mouth with salivary amylase- then inactivated in stomach by pH

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41
Q

When food enters the intestine after the stomach , what will re-add salivary amylase?

A

Pancreas

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42
Q

What are polysaccharides broken down into in the stomach ?

A

Alpha-Dextrins

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43
Q

how does salivary amylase digest polysaccharides ?

A

hydrolyzes the internal Alpha-1-4 bonds to make Disaccharides and Oligosaccharides

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44
Q

What are the primary Disaccharides ?

A

Lactose
Maltose
Trehalose

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45
Q

What is Lactose made from?

A

Galactose and Glucose

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46
Q

What is Trehalose made from?

A

Glucose + Glucose

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47
Q

Once the monosaccharides are in their singular form, they are transported from the lumen into the capillaries via :

A

Secondary Active transport

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48
Q

What is the first step/ first regulated step of Glycolysis ?

A

Phosphorylation of Glucose into Glucose 6-P

  • by Hexokinase
  • or by Glucokinase (liver)
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49
Q

True or False:

The phosphorylation of glucose is reversible and it is not trapped in the cell.

A

False- the phosphorylation is irreversible and it is trapped in cell once phosphorylated

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50
Q

What are the four main fates of Glucose after it has been phosphorylated into Glucose 6-P ?

A

Glycolysis
Glycogen synthesis
Pentose phosphate pathway
“Other pathways”

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51
Q

What happens in Glycolysis after Glucose is phosphorylated ?

A

Glucose 6-P is isomerized by phosphoglucoisomerase

-to Fructose 6-phosphate

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52
Q

What happens after you have the Fructose 6-phosphate in Glycolysis ?

A

Fructose 6-P is phosphorylated by phosphofructokinase (enzyme), second ATP is used for this

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53
Q

What does Fructose 6-P turn into after it is acted on by phosphofructokinase?

A

Fructose 1,6 -bisphosphate (phosphate groups on opposite ends)

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54
Q

What is the next enzyme to act on Fructose 1,6 bisphosphate ?

A

Aldolase - cleaves the 6 C chain inhalf to make 2 products

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55
Q

What two products will Aldolase make when it cuts Fructose 1,6-bisphosphate in half?

A
  1. Dehydroxyacetone phosphate

2. Glyceraldehyde3-phosphate

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56
Q

What is the enzyme that can catalyze the reversible changing between Dihydroxyacetone phosphate and Glyceraldehyde 3-phosphate

A

Triosephosphate isomerase

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57
Q

What will produce the first NADH in glycolysis ?

A

Enzyme glyceraldehyde 3-P dehydrogenase is used in Dehydrogenation reaction on Glyceraldehyde 3-P (removes H+)

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58
Q

What is the oxidation of glyceraldehyde 3-P dependent upon?

A

A cysteine residue in the active site of the enzyme - allowing a high energy thio-ester bond- intermediate will accept free phosphate and donate H to NAD

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59
Q

What is the next product in glycolysis after Glyceraldehyde 3-Phosphate?

A

1,3 Bisphosphoglycerate (has 2 phosphate groups)

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60
Q

What is 1,3-Bisphosphogylcerate used for in Glycolysis ?

A

Donates phosphate to ADP to make ATP (2 total per one glucose molecule)

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61
Q

What happens to 1,3 bisphosphoglycerate after it is acted upon by phosphoglycerate kinase ?

A

Turns into 3-phosphoglycerate

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62
Q

What does 3-phosphoglycerate get acted upon by ? what does it turn into?

A 
Phosphoglycerate mutase (enzyme moves the phosphate group)
=  2-Phosphogylcerate
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63
Q

What is the last high energy intermediate in Glycolysis that is used to make ATP?

A

Phosphophenol pyruvate (P- is on middle C)

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64
Q

How do you get Phosphophenol pyruvate ?

A

Removal of H2O from 2-phosphoglycerate (OH- off of the 3 carbon)

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65
Q

What is the first high energy intermediate used to make ATP in glycolysis ?

A

1,3-Bisphosphoglycerate

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66
Q

What does Phosphophenol pyruvate turn into after it loses its Phosphate to make ATP?

A

Pyruvate

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67
Q

What type of reaction occurs between the high energy intermediates of glycolysis to make ATP at the end of the process?

A

Substrate level phosphorylation

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68
Q

For every One glucose you can make ___ Pyruvate , ____ NADH, and ___ ATP net total. (2 ATP are used up in beginning.

A

2
2
2

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69
Q

What is the overall Delta G of Glycolysis ?

A
  • 22kg/M

- very powerful resisting reverse direction without input of energy to reverse it

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70
Q

What are the two primary fates of pyruvate?

A
  1. Aerobic glycolysis it is accepted by TCA cycle and turned into Acetyl CoA
  2. Anaerobic glycolysis - reduced to Lactate by Lactate dehydrogenase
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71
Q

What does Lactate Dehydrogenase do ?

A

reduces Pyruvate (adds 2 H) to make Lactate (acid)

  • NADH is donating the H
  • reversible
  • used in anaerobic conditions
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72
Q

What are the two phosphorylated molecules in glycolysis with high phosphate transfer potential?

A

1,3-Bisphosphoglycerate

Phosphophenolpyruvate

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73
Q

What 3 primary places is Glycolysis regulated at ?

A
  1. Hexokinase or Glucokinase (enzymes)
  2. Phosphofructokinase-1 (enzyme)
  3. Pyruvate Kinase (enzyme)
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74
Q

Regulation of Hexo or glucokinase is regulated by ?

A

Product - Glucose-6-P (elevated levels)
or
Glucokinase is also regulated by regulatory protein that binds it and will release it in the presence of Glucose or Fructose-1 phosphate so it can be active

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75
Q

What is phosphofructokinase-1 (enzyme)activated /enhanced by

A
  1. high levels of AMP

2. Fructose 2,6 bisphosphate

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76
Q

What can inhibit phosphofructokinase-1 (enzyme ?

A
  1. ATP

2. Citrate

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77
Q

Where does Fructose 2,6 phosphate come from? is it part of glycolysis ?

A

Not part of glycolysis

  • Fructose 6-P is phosphorylated into F 2,6-P by Phosphofructokinase 2
  • it will be a precursor that enhances phosphofructokinase -1 activity
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78
Q

Fructose 2,6 Bisphosphate is a ______ to the enzyme Phosphofructokinase-1 that is used to make Fructose 1,6 bisphosphate in glycolysis.

A

stimulator

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79
Q

Phosphofructokinase 2 is a _____ enzyme with two domains. It has 2 domains Kinase domain and phosphatase domain.

A

Bifunctional enzyme

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80
Q

What are the two domains of phosphofructokinase 2 ?

A
  1. Kinase domain (PFK2)

2. Phosphatase domain (FBP2)

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81
Q

What does the kinase domain do in the phosphofructokinase 2 ?

A

it will add free phosphate to Fructose 6-Phosphate to make Fructose 2,6, bisphosphate (stimulating product for phosphofructokinase 1 enzyme in glycolysis)

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82
Q

What does the phosphatase domain on Phosphofructokinase 2 do ?

A

Removes phosphate from Fructose 2,6 bisphosphate

- used in gluconeogenesis

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83
Q

What is Citrate ? how does it inhibit Glycolysis

A

intermediate of TCA cycle that is transported out of mitochondria into cytosol
-accumulation will block oxidation of glucose in cytosol

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84
Q

What enzyme does accumulation of citrate inhibit?

A

phosphofructokinase-1

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85
Q

What will stimulate Pyruvate Kinase?

A
  1. Fructose 1,6, bisphosphate (upper product of pathway stimulating lower part of pathway)
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86
Q

What will inhibit pyruvate kinase?

A

ATP

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87
Q

What can 2,3 bisphosphoglycerate function as ?

A

regulator of hemoglobin -influences binding of oxygen to hemoglobin

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88
Q

Acetyle CoA (within mitochondira) can be used to synthesis alternatively to make ________.

A

Fatty acids

89
Q

Glucose 6-Phosphate can be converted to Glycerol-P (3 carbon molecule) used as backbone in _______ which combines 3 fatty acids and one glycerol molecule.

A

Triglycerides

90
Q

When Fructose 2,6 phosphate levels are elevated in the cell, what is true for the cell?

A
  1. Glucose levels are high
  2. PFK 1 will be activated
  3. Pyruvate kinase will be activated (PFK1 stimulates this)
  4. NADH production is increased
91
Q

Where can glycogen synthesis occur?

A

Muscle and Liver

92
Q

What is the role of glycogen in muscle?

Is Glucose 6-P from muscle ever released into circulation?

A

produced and released for muscle itself under anaerobic conditions (makes CO2 and lactate)

-never released into circulation

93
Q

What enzyme does the muscle lack so that Glucose 6-P can not leave the muscle cells to enter circulation as free glucose?

A

Glucose 6-phosphatase (would remove required phosphate group that allows glucose to leave cells)

94
Q

What allows the glucose to be released from the liver to maintain blood levels?

A

Glucose 6-phosphatase (removes the phosphate group from glucose)

95
Q

In Glycogen synthesis what enzyme will act to convert Glucose 6-Phosphate into Glucose 1-Phosphate ?
Is it reversible and used in the opposite direction for degradation?

A

Phosphoglucomutase

-Yes it is reversible and used in synthesis and degradation

96
Q

Glycogen synthesis is an energy requiring pathway, it will use ____ to be charged.

A

UTP

97
Q

What enzyme will charge Glucose 1-P to make UDP-Glucose in the glycogen synthesis pathway ?

A

UDP-glucose pyrophosphorylase

uses UTP as substrate

98
Q

UDP-Glucose is added to preexisting _______ molecules that usually consist of several branch points in glycogen synthesis.

A

Glycogen

99
Q

What are the 2 enzymes for the reaction that will add UDP-Glucose to branch points on existing glycogen molecules?

A

Glycogen synthase

4,6 Transferase (branching enzyme)- moves the attached molecule around on chain

100
Q

True or False:

UDP is not regenerated in the degradation of glycogen because the synthesis is an energy requiring pathway.

A

True

101
Q

What is the primary degradation enzyme in glycogen degradation

A

Glycogen phosphorylase

102
Q

What are the 3 enzymes needed in glycogen degradation in order?

A
  1. Debrancher enzyme
  2. Glycogen phosphorylase
  3. Glucose-6 phosphatase (only in liver- so glucose can leave cell)
103
Q

What 2 enzymes are used to add molecules to Glycogen?

A

Glycogen synthase

4,6 Transferase

104
Q

the branch points on the Glycogen core are held together by ?

A

Glucose reside and alpha-1,6 linkage

105
Q

On the branch chains, the molecules are added and held together by /

A

Glucose residue and alpha 1,4 linkage

- once a certain length the 4,6 transferase will move remove the extended chain and use alpha 1-6 linkage again on core

106
Q

what does 4,6 transferase do in glycogen synthesis?

A

it will remove the extended chain from glycogen, then move a portion of the chain to core with alpha 1-6 linkage to make branches (more room on all nonreducing ends of sugars)

107
Q

In glycogen degradation, Glycogen phosphorylase will free glucose from chains by addition of ____ _____. This will generate ________.

A

Free phosphate

Glucose 1-phosphate

108
Q

Glycogen phosphoryalse activity is constrained when…..

A

the glycogen chain is shortened near a branch point.

109
Q

What will the 4:4 transferase do in glycogen degradation when the branch chain becomes too short for Glycogen phosphorylase to act on it?

A

remove the Alpha 1-6 glucose residue linkage

move it to be incorporated into the Glycogen core

110
Q

After the Transferase 4:4 moves the short chain to be incorporated into the core, what enzyme can act to remove one glucose molecule that is left on branch point?

A

Alpha-1,6 Glucosidase

111
Q

Glycogen phosphorylase and Glycogen synthase are heavily regulated so that ?

A

Synthesis and degradation of glycogen is not occurring at the same time

112
Q

How is Glycogen phosphorylase and Glycogen synthase regulated?

A

through phosphorylation and dephosphorylation reactions to activate and inactive (they are opposite eachother)

113
Q

When you phosphorylate Glycogen phosphorylase is it active or inactive ?

A

Active

114
Q

When you phosphorylate Glycogen synthase is it active or inactive?

A

Inactive

115
Q

If there is no phosphate attached to the Glycogen phosphorylase enzyme, is it active or inactive?

A

inactive

116
Q

_____ and _____ will stimulate Glycogenolysis (glycogen degradation)

A
  1. Glucagon (liver)- no impact on muslce

2. Epinephrine (muscle and liver)

117
Q

_____ will stimulate glycogen synthesis in the muscle and liver

A

Insulin

118
Q

Glucagon and epinephrine will bind to a _______ on the cell membrane.

A

G-coupled protein

-family of heteromeric proteins associated

119
Q

G proteins after being activated by Glucagon or Epinephrine will detach and bind GTP to activate?

A 
Adenylate cyclase (in membrane)
-Converts ATP into cAMP
120
Q

cAMP will be a second messenger (in glucagon and epinephrine pathway) and will bind ________ when it is inactive to make the active form.

A

Protein Kinase A

121
Q

Protein kinase A will regulate _______ by adding a phosphate to inactivate it, and ____ by adding a phosphate to activate it.

A

Glycogen synthase (inactivates)

Glycogen phosphorylase (activates)

122
Q

Protein Kinase A will function to phosphorylate Phosphorylase kinase to make it active (added P to it), which will then phosphorylate _______ into its active form.

A

Glycogen phosphorylase (B)

  • active when phosphorylated
  • used in glycogen degradation pathway to add free phosphate to glucose molecules to make Glucose 1-P off of glycogen
123
Q

Protein kinase A will take Phosphate from ATP to add a P to ______ to inactivate it.

A

Glycogen Synthase

124
Q

What is the secondary (besides the G-protein) receptor that epinephrine can bind on the liver

A

Alpha-agonist receptor (has its own G-protein associated receptor)

125
Q

What will binding the alpha-agonist receptor (has its own G-protein associated receptor) do when epinephrine binds it in the liver?

A

will increase glycogen degradation - through manner that is Calcium regulated

126
Q

In the cascade with the alpha agonist receptor that epinephrine binds to in the liver after the G-protein that is associated with the agonist receptor is activated?

A

It will bind and activate Phospholipase C

that will facilitate cleavage of PIP(2) into IP3 and DAG

127
Q

What does Diacylglycerol (DAG) do once activated by the cleavage of PIP by Phospholipase C?

A

Stimulate activity of protein kinase C- will phosphorylate the Glycogen synthase then inactivating it

128
Q

What will the Inositol-Phosphate 3 (IP3) do once it is activated by cleavage of the PIP2 in the membrane by active phospholipase C ?

A

IP3 will stimulate release of Ca+ from the Endoplasmic reticulum
- then will bind Ca+ calmodulin binding protein that leads to inactivating Glycogen synthase and activating Glycogen phosphorylase

129
Q

What does Ca+ calmodulin do once Ca+ that was released from the ER by Inositol-phosphate 3 activation ? it has 2 effects….

A
  1. activation of Calmodulin-dependent protein kinase ( inactivates glycogen synthase)
  2. activation of Phosphorylase kinase (inactivates glycogen synthase and activates glycogen phosphorylase)
130
Q

What can Calmodulin dependend protein kinase do once activated by Ca+calmodulin

A

phosphorylate the Glycogen synthase which inactivates it

131
Q

What can Phosphorylase kinase do once it is activated by Ca+calmodulin ?

A

Phosphorylate the Glycogen phosphorylase to then activate it

- will phosphorylate Glycogen Synthase to inactive it at the same time

132
Q

Glycogen synthase has different sites for the different enzymes that can phosphorylate it to inactivate it, what are the 3 enzymes that can do this?

A
  1. Protein kinase C (from DAG)
  2. Calmodulin-dependent protein kinase
  3. Phosphorylase kinase
133
Q

Glycogen synthesis is primarily controlled by _______ in the muscle.

A

exercise

134
Q

Primary metabolism of glycogen in muscle will lead to production of _____ for use in anaerobic exercise.

A

Glucose -1 P- then leads to lactic acid

135
Q

Cascade in skeletal muscle with Epinephrine binding G-protein, leading to cAMP activating _____. this then leads to phosphorylating _______ then phosphorylating _______ to activate it.

A

Protein kinase A (same as in liver)

Phosphorylase kinase

Glycogen phosphorylase a (degradation)

136
Q

What are the two ways Glycogen degradation can be stimulated in muscle?

A
  1. Epinephrine binding to G-protein receptors leading to activation of Protein kinase A
    or
  2. Nerve impulse leading to Ca+ release from ER then Ca+calmodulin activation
    (both will converge at phosphorylating phosphorylase kinase that then phosphorylates Glycogen phosphorylase a)
137
Q

What is an allosteric activator of Glycogen phosphorylase b (degradation) in the muscle?

A

Muscle contraction

  • high levels of AMP will be allosteric activator (=high levels of muscle contraction)
  • independent of phosphorylation cascades
  • ensures the muscle can support itself during exercise
138
Q

In the Liver, during a fasting state, what is happening to glucagon, insulin, cAMP (regulators) ?
what is happening to glycogen degradation and synthesis (tissue response)?

A
  1. Glucagon = increased
  2. Insulin = decreased
  3. cAMP = increased
degradation = increased
synthesis = decreased
139
Q

In the liver, after a carbohydrate meal, what is happening to glucagon, insulin, cAMP and glucose levels (regulators)?
what is happening to glycogen degradation and synthesis (tissue response) ?

A

Glucagon = decreased
Insulin = increased
Glucose = increased
Tissue cAMP = decreased

degradation = decreased
synthesis = increased
140
Q

In the liver, after exercise and stress, what is happening to Blood epinephrine, tissue cAMP, and Ca+calmodulin levels (regulators) ?
degradation and synthesis of glycogen?

A

Blood epinephrine = increased
Tissue cAMP = increased
Ca+calmodulin = increased

degradation = increased
synthesis = decreased
141
Q

In the muscle, what is happening during fasting (rest) with blood insulin levels ?
Glycogen synthesis and Glucose transport?

A

Blood:insulin - decreased

Synthesis = decreased
Transport = decreased
142
Q

What happens in muscle after a carbohydrate meal to blood insulin regulator?
Glycogen synthesis ?
Glucose transport?

A

Blood insulin = increased

Glycogen synthesis = increased
Glucose transport = increased

143
Q

What happens in the Muscle after Exercise to regluators: blood epinephrine, tissue AMP, Ca+calmodulin, and cAMP?
Glycogen synthesis and degradation?
Glycolysis?

A

Blood epinephrine = increased
Tissue AMP = decreased
Ca+calmodulin = increased
cAMP = increased

Glycogen synthesis = decreased
Glycogen degradation = decreased
Glycolysis = increased

144
Q

Insulin stimulates all of the following pathways except:

  1. Glycolysis
  2. Amino Acid catabolism
  3. Glycogen synthesis
  4. Fatty acid synthesis
A
  1. Amino acid catabolism
  • Insulin is an anabolic hormone that facilitates synthesis
  • Cortisol is responsible for mobilization of AA from muscle
145
Q

Insulin stimulates fatty acid synthesis in liver. These fatty acids are transported to the adipose tissue as:

A

VLDL particles

146
Q

The release of insulin from the pancreatic Beta-Cells is mediated by which of the following processes:

  1. Decrease in blood glucose
  2. Increase in glucagon
  3. Increase in intracellular calcium
A
  1. Increase in intracellular calcium
147
Q

Von Gierkes disease is a glucogen storage disease of which area?
Which area is McArdles disease ?

A
  1. Storage in liver

2. Storage in skeletal muscle

148
Q

When glucagon is elevated what is true for McArdles patients only and not Von Gierke’s disease patients?

A

Patient will fatigue easily during exercise - they can not store glycogen

149
Q

What three things occur for Von gierkes disease patients (glucogen storage deficent in liver) when glucagon is elevated?

A
  1. Patient will present with lactic acidemia
  2. Patient will become hypoglycemic after a fast
  3. Patient will have elevated fructose 2,6 phosphate levels
150
Q

What is absent in patients with McArdles disease?

A

Glycogen synthase in Skeletal Muscle

  • Glycolysis is reduced
  • ATP levels reduced
151
Q

What is absent in Von Gierkes disease patients in the liver?

A

Glucose 6-phosphatase is missing

  • Glucose 6-P can not be converted into usable Glucose
  • increases flux of glycolysis so that overflow goes into lactate production and TCA cycle as Acetly coA
152
Q

What compound allosterically activates phosphofructokinase 1?

A

Fructose 2,6 bisphosphate

153
Q

What is an insulin insensitive GLUT transported found primarily on the liver?

A

GLUT2 transporter

154
Q

The isozyme of Hexokinase called Glucokinase that is found in the ______ and Beta cells of the _______ has a much ______ Km than other hexokinases.

A

liver
pancreas
higher

155
Q

______ will irreversibly commit Glucose-6 Phosphate to the glycolytic pathway. It converts Fructose 6-P to Fructose 1,6 bisphosphate (adds P using ATP).

A

Phosphofructokinase-1 (PFK-1)

156
Q

What molecule is cleaved by Aldolase to make the set of 2 3 carbon molecules in glycolysis ?

A

Fructose 1,6 bisphosphate

157
Q

The oxidation of Glyceraldehyde 3-P by Gyceraldehyde 3-p dehydrogenase is dependent on a ____ residue at the active site of the enzyme which forms a high energy _____ bond during the course of the reaction. NAD+ will change to NADH

A

Cysteine

thioester

158
Q

Glyceraldehyde 3-P is dehydrogenated and then its high energy intermediate will accept an inorganic phosphate to form the high energy acyl phosphate bond making _________. This is the start of substrate level phosphorylation.

A

1,3-bisphosphoglycerate

159
Q

What will transfer the P from 1,3-bisphosphoglycerate to ADP?

A

Phosphoglycerate kinase

- next product is then 3-phosphoglycerate

160
Q

What are the two ways that NADH is oxidized to make sure it is in supply for use in the dehydrogenation of glyceraldehyde 3-P?

A
  1. Aerobic- shuttling the H across the mitochondrial membrane
  2. Anaerobic- Lactate Dehydrogenase will reduce pyruvate to lactate and take H from NADH
161
Q

What are the two main shuttles that can transport the H across the mitochondrial membrane ?

A

Glycerol 3-P shuttle

Malate-aspartate shuttle

162
Q

In the Glycerol 3-P shuttle, what are the Electrons from NADH dropped of on inside the mitochondria?

A

FAD will pick them up and then take them to CoQ in the ETC

163
Q

In the glycerol 3-P shuttle what is precursor to Glycerol 3-P before it picks up H from NADH?

A

Dihydroxyacetone -P

164
Q

In the Malate-aspartate shuttle, what does the NADH need to drop its H off on and converts it to what for transport across the membrane?

A

Drops the H on Oxaloacetate that changes it to Malate

Malate crosses then drops of H to NAD

165
Q

If the NADH is oxidized by the Glycerol-3-P shuttle what is the production of ATP?
What if its oxidized by the Malate-aspartate shuttle?

A

Glycerol 3-P = 1.5 mol of ATP per mol of NADH

Malate-Aspar = 2.5 mol of ATP per mol of NADH

thus the 2 NADH in glycolysis can lead to 3-5 ATP

166
Q

How many ATP can each mol of Pyruvate give in aerobic glycolysis ?

A

12.5

167
Q

How many mol of ATP can be produced from 1 mol of glucose when it is fully oxidized to CO2?

A

30 to 32
12.5- per pyruvate
3-5 for NADH
2 from Glycolysis

168
Q

What two AA can the Glycolytic pathway produce?

A

Alanine

Serine

169
Q

The liver synthesizes fatty acids from the ______ generated by glycolysis .

A

Pyruvate

170
Q

The liver also functions as a reversal of glycolysis synthesizing glucose from ______, _____, and ______.

A

Lactate
Glycerol 3-P
AA

171
Q

Red blood cells form _______ to serve as an allosteric inhibitor of oxygen binding to heme. Most cells only need very small amounts of it as it is not depleted.

A

2,3 bisphosphoglycerate

172
Q

What are the three enzymes in glycolysis that are inhibited by feedback inhibition due to high levels of ATP ?

A
  1. Phosphofructokinase-1 (PFK-1)
  2. Pyruvate Kinase (only for liver-inhibits glycolysis if gluconeogenesis is occurring)
  3. Pyruvate Dehydrogenase (converts pyruvate to AcetylCoA)
173
Q

The activity of ____ _____ in the mitochondrion determines whether pyruvate is converted to lactate or to acetyl coA in the Mitochondria for TCA cycle.

A

Pyruvate dehydrogenase

174
Q

What does the higher Km of glucokinase in the liver allow for ?

A

its own product Glucose-6 P is less likely to inhibit the pathway allowing glycolysis to continue in liver even when energy levels are high - in other tissues with Hexokinase (lower km) its own product will inhibit it much faster

175
Q

PFK-1 is an ______ enzyme that has a total of six binding sites: two are for substrates, and four are allosterically regulated sites.

A

Allosteric

rate limiting enzyme of Glycolysis

176
Q

what are two allosteric activators of PFK-1 ?

A

AMP and Fructose 2,6-bisphosphate (opposes ATP inhibition)

177
Q

True or False:

Fructose 2,6-bisP is an intermediate of Glycolysis

A

False

  • it is an allosteric activator of PFK-1
  • synthesized by PFK-2
178
Q

In skeletal muscle, high concentrations of Fructose-6 P activate the kinase and inhibit the phosphatase, thereby increasing the concentration of fructose 2,6-bisP and ____ ______.

A

activating glycolysis

179
Q

What can PFK-2 be regulated by ?

A

Ratio of activation of kinase vs phosphatase domain

  • phosphorylation by serine-threonine protein kinases
  • cAMP-dependent protein kinase (protein kinase A) will deactivate PFK-2 due to circulating levels of glucagon during fasting states
180
Q

What can inhibit Pyruvate Dehydrogenase ?

A

Increased levels of NADH

Increased levels of its own product-acetyl CoA

181
Q

What is an activator of pyruvate dehydrogenase?

A

increased ADP

Increased Ca+

182
Q

What is the bond on glycogen between the core glucose molecules?

A

alpha-1,4 glycosidic bonds

183
Q

What is the bond on glycogen between the core and a branch?

A

alpha 1,6 (branches every 8 to 10 residues)

184
Q

What is Glycogen degraded to ?

A

Glucose 1-P then Glucose 6-P then it has several different paths it can go , only in liver is Glucose 6-phosphatase avaliable to export glucose to blood

185
Q

What is the general path of glycogen synthesis ?

A

Glucose to Glucose 6-P to Glucose 1-P to UDP-Glucose (can go to other pathways from here ) or Glycogen synthase can make this into Glycogen

186
Q

What is the first and then second enzyme in glycogen degredation?

A
  1. Debrancher enzyme

2. Glycogen phosphorylase

187
Q

What does Glycogen phosphorylase do ?

A

changes glycogen into Glucose 1-P

188
Q

What does Phosphoglucomutase do ?

A

Can either make Glucose 1-P into Glucose 6-P or do the reverse

189
Q

Glycogen degradation is a ______ reaction (breaking of a bond using a phosphate ion as a nucleophile)

A

Phosphorolysis

190
Q

What membrane bound enzyme will degrade cAMP rapidly back to AMP?

A

Phosphodiesterase

191
Q

What sequence of enzymes allows for the synthesis of glycogen from glucose 6-P

A
  1. Phosphoglucomutase
  2. UDP-glucose pyrophosphorylase
  3. Glycogen synthase
  4. amylo-(1,4a1,6)-transflycosylase
192
Q

What intermediate is an allosteric activator of pyruvate Kinase?

A

Fructose 1,6-bisphosphate

193
Q

During the fasted state (glucagon is high), what is the state of glycogen phosphorylase and glycogen synthase

A

both are phosphorylated

-only the glycogen phosphorlyase is active

194
Q

Epinephrine acting on beta receptors on liver, transmit signals through ____ to adenylate cyclase,which increases _____ levels and activate PKA.

A

G Proteins

cAMP

195
Q

Epinephrine acting at Alpha receptors on hepatocytes will inhibit glycogen synthesis primarily by ….

A

increasing levels of Ca+ mediated by PIP2 -Ca+ transduction system through Phospholipase C

196
Q

What cells release Insulin?

A

Pancreatic Beta cells

197
Q

To release Insulin, pancreatic beta cells will have a change in intracellular glucose which increases ATP. Increased ATP will ______ K+ release .

A

Inhibit

198
Q

Inhibiting K+ release after ATP increases in the Beta pancreatic cells, will _____ the cell.

A

Depolarize

199
Q

Depolarizing the Beta pancreatic cell will ________ intracellular Ca+ which facilitates exocytosis of ______.

A

increase

Insulin

200
Q

Insulin enhances what three synthesis processes in the liver?

A

Glycogen synthesis
Fatty acid synthesis
Protein synthesis

201
Q

Insulin enhances what two processes in the Adipose?

A

Triacylclyerol synthesis

Glucose uptake through GLUT4

202
Q

Insulin enhances what two processes through Skeletal muscle?

A

Glucose uptake through GLUT4

Protein synthesis

203
Q

Where is the GLUT 2 transporter mainly found?

A

Liver- high capacity for Glucose but low affinity

204
Q

What cells release Glucagon in response to low blood glucose?

A

Pancreatic Alpha cells

205
Q

What does Glucagon enhance in the liver?

A

Glycogenolysis
Gluconeogenesis (AA substrates)
Oxidation of fatty acids

206
Q

What does glucagon enhance in the adipose?

A

Lipolysis

207
Q

What does glucagon enhance in the skeletal muscle?

A

no impact

208
Q

Epinephrine signals through ________ in the liver or the ______ in skeletal muslce.

A

Alpha agonist receptor (liver)

GPCR (skeletal muscle)

209
Q

What effect does epinephrine have on the Liver?

A
  1. Glycogenolysis (increase of Phospholipase C, Ca+ and inhibits Glucagen synthesis)
  2. Oxidation of fatty acids (generation of ketones)
210
Q

What does epinephrine do to the adipose?

A

lipolysis

211
Q

what does epinephrine act through and cause in the skeletal muslce?

A

Glycogenolysis

-through cAMP pathway

212
Q

Cortisol will bind an intracellular receptor and mediate changes through _____ ______.

A

transcriptional regulation

213
Q

In skeletal muscle, cortisol will promote ______ _____ to provide AA for _______ occuring in the liver.

A

Protein catabolism

Gluconeogenesis

214
Q

What are the primary Monosaccharides?

A

Glucose
Galactose
Fructose

215
Q

What are the primary Disaccharides?

A

Trehalose (2 glucose)
Lactose
Sucrose

216
Q

When Phosphofructokinase 2 is dephosphorylated, it is _____.

A

Active

217
Q

What 2 steps in Glycolysis will use ATP for cofactor?

A
  1. Hexokinase or Glucokinse uses it - creation of Glucose 6P

2. Phosphofructokinase-1 uses it to make Fructose 1,6 bisphosphate

218
Q

Elevated AMP will allosterically activate _____ _______.

A

Glycogen phosphorylase B

Biochemistry (20 decks)

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