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Physiology > carbohydrate > Flashcards

carbohydrate Flashcards

1
Q

MOST important member of the sugar family

One of the main sources of calories
- Can cross blood-brain barrier and nourishes the brain

A

GLUCOSE

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2
Q

one sugar molecule

A

Monosaccharide

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3
Q

2 sugar molecules

A

Disaccharide

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4
Q

3 to 9 sugar molecules

A

Oligosaccharide

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5
Q

10 or more sugar molecules (most abundant
carbohydrate in food)

A

Polysaccharide

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6
Q

breakdown large polysaccharides (e.g., starch)

A

Amylases

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7
Q

breakdown lactose

A

Lactase

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8
Q

breakdown sucrose

A

Sucrase

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9
Q

breakdown maltose

A

Maltase

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10
Q

found in honey, fruits, and root vegetables

A

fructose

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11
Q

The individual __________that result from the digestion of larger carbohydrate molecules will cross the gut lining and get into
bloodstream to get used by the body.

A

monosaccharides

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12
Q

milk sugar.

only found in nature when it is links with glucose to form lactose

A

galactose

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13
Q

found in milk of mammals

cow milk and breast milk

A

lactose (beta 1-4 glycosidic bond)

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14
Q

fructose + glucose

table sugar

sugar cane and sugar beets

A

sucrose (alpha 1, 2 glycosidic bond)

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15
Q

found in molasses

used to ferment beer

A

maltose (alpha 1-4, glycosidic bond)

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16
Q

healthy diet:

A

45-65% of calories from the carbohydrates

fiber - 28g (2cal/1g) = 56cal (3%)
sugars - 100g -> 400cal (20%)
added sugars 100 cal (5%)
natural (f, v, g) 300 cal (15%)
STARCHES 160g 640 cal (32%)

0.55 (2000) = 1100 cal

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17
Q

mono and di that body can readily absorb

A

simple sugars

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18
Q

polysaccharide that takes longer to absorb

A

starches

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19
Q

can only partially absorb with gut bacteria

A

fibers

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20
Q

When glucose level in blood increases after eating,
pancreas releases ________ which helps move glucose into the cells for energy

A

insulin

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21
Q

helps stimulate the liver to store glucose as
glycogen (process is glycogenesis)

promotes fat and protein synthesis

A

Insulin

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22
Q

In the liver, metabolism of galactose has an initial step where an enzyme in the liver converts galactose into ________

(flipping the OH orientation of the 4th carbon)

A

glucose

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23
Q

In the liver, fructose is usually broken down into two 3-carbon molecules will be used in glycolysis to help generate energy.

what molecule is this?

A

two molecules of glyceraldehyde-3-phosphate (G3P)

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24
Q

When energy is needed, monosaccharides are metabolized through ___

A

glycolysis – citric acid cycle – oxidative phosphorylation

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25
Q

is the first step in the breakdown of glucose or other monosaccharides.

It takes place in the CYTOPLASM of the cell and does not require oxygen.

a molecule of glucose is broken down into two molecules of PYRUVATE (a 3-carbon compound).

This process generates a small amount of ATP and NADH.

A

Glycolysis

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26
Q

In aerobic conditions (when oxygen is available), pyruvate (the product of glycolysis) is further metabolized.

It enters the MITOCHONDRIA, where it is converted into acetyl-CoA

This step releases more NADH.

A

Pyruvate Decarboxylation

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27
Q

Acetyl-CoA enters a series of enzymatic reactions that occur in the mitochondria.

During this cycle, acetyl-CoA is further broken down, releasing carbon dioxide and generating more ATP, NADH, and FADH2.

A

Citric Acid Cycle (Krebs Cycle)

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28
Q

The NADH and FADH2 produced in glycolysis, pyruvate decarboxylation, and the citric acid cycle are used in the ___________

This chain is located in the inner mitochondrial membrane and is involved in the final stages of energy production.

A

Electron Transport Chain (ETC)

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29
Q

As electrons move through the ETC, they create a proton gradient, and this gradient is used to generate ATP

A

Oxidative Phosphorylation

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30
Q

The final result of these processes is the production of a significant amount of ATP, which is the cell’s primary energy source.

ATP can be used by the cell for various energy-requiring processes, such as muscle contraction, active transport, and biochemical reactions.

A

ATP Production

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31
Q

is the major regulator of both storage and
distribution of glucose towards the peripheral tissue.

In particular, to the glucose dependent tissues such as the BRAIN and ERYTHROCYTES.

A

liver

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32
Q

Both our muscle and liver store glucose in the form of __________

A

Glycogen

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33
Q

only the LIVER can break down the glycogen to glucose in order to provide for the _________

A

systemic circulation

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34
Q

Once the carbohydrate is broken down into simple sugar, it is absorbed in our intestine and distributed ___________.

A

systemically

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35
Q

Our liver provides __________ of glycogen per kilogram of liver tissue.

The excess glycogen is converted into fatty acid and
stored in an adipose tissue,

A

65 grams

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36
Q

During the postabsorptive state in our body, our LIVER becomes the primary source of glucose.

However, most of our muscles rely on fatty acids from the ________

A

adipose tissue

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37
Q

An active muscle may deplete its own and glycogen and they start to be dependent on the ________

A

Liver-glycogen

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38
Q

After 48hrs of fasting, our liver shifts from glycogenesis to ____________

A

gluconeogenesis

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39
Q

The _________ is depleted the reason why our liver would shift from glycogenesis to gluconeogenesis

A

hepatic glycogen

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40
Q

The substrate for gluconeogenesis is mostly the ______

A

amino acids (specifically the alanine)

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41
Q

The alanine is derived from muscle breakdown and
glycerol form adipose tissue become the __________.

A

substrate

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42
Q

in a prolonged fasting, the fatty acids are β-oxidized in the liver.

This would result to the release of the ___________ which will became the primary source of fuel for the brain

A

ketone bodies

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43
Q

The transition of in and out of these various metabolic state and regulation of carbohydrate metabolism are influenced by glucose concentration in _______ & __________

A

sinusoidal blood and hormonal cells

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44
Q

During anaerobic metabolism, our liver uses LACATE, that is converted into pyruvate that enters the __________ in order to produce glucose.

A

gluconeogenic pathways

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45
Q

Lactate helps in producing more glucose.
This process in known as the _____

A

Cori Cycle

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46
Q

is an abnormal glucose intolerance

A

Liver cirrhosis

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47
Q

will ensue when too much liver tissue
is destroyed when gluconeogenesis fails.

A

Hypoglycemia

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48
Q

breakdown fuel molecules that transfer high energy
compounds like ATP, Guanosine Triphosphate, flavine, reduced adenine dinucleotide phosphate.

A

Cellular Respiration

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49
Q

The breakdown starts from the digestion of the food in the gastrointestinal tract and followed by the absorption of the carbohydrates component by
ENTEROCYTES by the form of monosaccharide

A

Cellular Respiration

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50
Q

The monosaccharides are transferred into the cells for anaerobic and aerobic respiration through _________ , _______, & _________ to be used during the starvation state

A

glycolysis,
citric acid cycle, and
pentose phosphate pathway

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51
Q

the muscle and the liver cells store monosaccharide in a form of glycogen

A

Normal state

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52
Q

the extra glucose is converted into triglycerides
through lipogenesis and stored as lipid droplets in the adipocytes

A

Obesity state

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53
Q

the lipid droplets of other tissues such as the liver,
skeletal muscle, and pancreatic beta cells also
accumulate triacylglycerol.

A

Lipotoxicity state

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54
Q

Access of pathogenesis of most metabolic
dysregulation such as insulin resistance, metabolic
syndrome, and diabetes

A

Lipotoxicity state

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55
Q

is a 6-carbon molecule that is used to make energy
in the form of ATP.

➢ Excessed of this are stored in both skeletal muscle cells and liver cells in the form of Glycogen.

A

Glucose

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56
Q

is a polymer that is made up of glucose
molecules linked together via glycosidic bond creating branched chains.

➢ This branching allows it to be compact and capable of rapid addition and removal of glucose.

A

Glycogen

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57
Q

4 Main Steps in Glycogen Synthesis

A

Step 1: Attaching Uridine Diphosphate (UDP) to Glucose
Step 2: Attaching Glucose to Glycogen Primer Called as Glycogenin

Step 3: Adding more Glucose to the Primer
step 4: adding more branches

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58
Q

an enzyme known as _________________moves
from the phosphate of the 6th carbon to the 1st carbon creating Glucose-1-phosphate

(comes in the form of Uridine triphosphate) step 1

A

Phosphoglucomutase

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59
Q

In the presence of Glucose-1-phosphate and UTP, an enzyme called ________________ cuts 2 molecules of phosphates off UTP leaving:

1 Phosphate attached to uridine and added with phosphate from the Glucose-1-phosphate.

A

UDP-Glucose Pyrophosphorylase

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60
Q

step 2 results to a molecule known as ________-

A

UDP Glucose

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61
Q

An enzyme known as ________ catalyzes the attachment of glucose the part of the UDP Glucose to another glucose residue at the end of the glycogen branch that forms an α-1,4 glycosidic bond.

The by-product of this reaction known as UDP.

A

Glycogen Synthase

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62
Q

The glycogen synthase only elongate an already existing glycogen chain that is at least 4 glucose molecules long.

However, if the chain do not have at least 4 glucose
molecules, the glycogen synthase would need to have __________-.

A

Glycogenin

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63
Q

__________ would fool the glycogen synthase through binding to the glucose molecules, looking like an old glycogen molecule

A

Glycogenin

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64
Q

The branching enzyme goes to the end of the chain and shortened it to about 68 glucose residues in length. The cut chain attaches to the side of the linear glycogen strand by_______

A

α-1,6 glycosidic bond

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65
Q

Once the chain is shortened, the glycogen synthase will elongate it again. This would then result to a glycogen tree of __________

A

stored energy

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66
Q

low glucose levels
pancreas secrete glucagon

A

adrenal glands secrete epinephrine to increase heart rate

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67
Q

glucagon tells the liver cells to _____

A

break down glycogen to individual glucose molecules

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68
Q

epinephrine tells skeletal muscle to

A

break down glycogen

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69
Q
  • begins w/ branches
  • glycogen phosphorylase
  • debranching enzyme
A

glycogen breakdown

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70
Q

cleaves alpha 1, 4 bonds
- catalyzes the transfer of phosphate group

  • release 1 glucose-1-phosphate
  • leaves 4 glucose
A

glycogen phosphorylase

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71
Q

cuts of branches

A

debranching enzyme: 4-alpha-glucanotransferaase

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72
Q

cleave alpha 1, 6 bond
release free glucose

A

debranching enzyme: alpha 1,6 glucosidase

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73
Q

in liver, ___________ removes phosphate

  • release free glucose in bloodstream for other organs to use
A

glucose-6-phosphatase

74
Q

muscles do not have glucose-6-phosphatase but uses glucose-6-phosphatase to:

A

make glycolysis pathway

and help you provide energy when you run

75
Q

transfer 3 glucose molecules off the
branch and reattach them to the linear glycogen, extending it as a result

A

4-alpha-glucotransferase

76
Q

For each glucose that’s removed via phosphorylases There’s a glucose 1-phosphate that gets liberated and it’s converted to glucose-6-phosphate by __________

A

phosphoglucomutase

77
Q

2 regulation of glycogen metabolism

A
  1. insulin
  2. glucagon
78
Q

active without phosphate

A

glycogen synthase

(makes active, glycogen synthesis)

79
Q

active with phosphate

A

glycogen phosphorylase

(makes inactive, glycogen breakdown)

80
Q

Insulin will attach to _____________ receptor,

which will activate a protein phosphatase that removes phosphates from the glycogen
synthase making it active

and glycogen phosphorylase, making it inactive

A

Tyrosine kinase

81
Q

glucagon on the liver cells bind to G-protein coupled receptor on the cell surface which activates _________

A

adenylyl cyclase

82
Q

converts ATP to cyclic AMP

A

adenylyl cyclase

83
Q

cyclic AMP activates ______

A

kinase A

84
Q

kinase a adds a phosphate to _______________ which activates it

A

glycogen phosphorylase kinase

85
Q

Glycogen phosphorylase kinase adds a
phosphate to _________________ increasing its activity and promoting glycogen breakdown.

A

glycogen phosphorylase

86
Q

Kinase a also adds a phosphate to the _______________ decreasing its activity and therefore decreasing glycogen synthesis

A

glycogen synthase

87
Q

the “Energy Currency” of the Body.

A

Adenosine Triphosphate

88
Q

containing two high energy phosphate bonds.

each of these phosphate bonds is approximately 12,000 calories under conditions found in the body.

A

ATP

89
Q

ATP is present in the ___________ & _______________

A

cytoplasm and nucleoplasm of all cells.

90
Q

Essentially all of the physiological mechanisms that require energy for operation obtain this energy directly from __________

A

ATP or GTP

91
Q

Normally,_________ or more of all the carbohydrates used by the
body are used for this purpose.

A

90 percent

92
Q

The final products of carbohydrate digestion🡪

A

glucose, fructose, and galactose.

93
Q

To enter the cell, these monosaccharides combine with protein carriers in the membrane that allow them to pass through the membrane via _________________ into the cell

A

facilitated diffusion

94
Q

The rate of carbohydrate utilization by the body is controlled to a great extent by the rate of ____________ secretion from the pancreas and the sensitivity of the various tissues to insulin’s effects on glucose transport.

A

insulin

95
Q

Phosphorylation of glucose is almost completely irreversible,

except in Liver cells, Renal tubular epithelium, and Intestinal epithelial cells,

where ____________ is available for reversing the reaction.

A

glucose phosphatase

96
Q

serves to capture glucose in the cell.

A

Phosphorylation

97
Q

Once in the cell, the glucose does not diffuse out except from special cells that have the necessary _____________.

A

phosphatase

98
Q

All cells of the body are capable of glycogenesis and storing some glycogen, but_____ & _______ can store LARGE quantities of it.

A

liver and muscle cells

99
Q

Very large glycogen can molecular weights up to 5 million

This very large glycogen molecules precipitate to form __________

A

solid granules

100
Q

In glycogenolysis, the glucose molecule on each branch of the glycogen polymer is split away by the process of _________

A

phosphorylation

101
Q

When it is required to re-form glucose from glycogen, phosphorylase can be activated by the hormones _____________ & _________

A

epinephrine and glucagon.

102
Q

The _____initiates a cascade of chemical reactions that activates the phosphorylase.

A

cAMP

103
Q

Glycolysis occurs in ____ successive steps, while each step is being catalyzed by at least one specific enzyme.

A

10

104
Q

The complete oxidation of 1 mole of glucose releases 686,000 calories of energy, but only _________ calories of energy are required to form 1 mole of ATP.

A

12,000

105
Q

The energy in glucose is released in small packets to form ______

A

one molecule of ATP at a time

106
Q

A total of ______ is formed for each mole of glucose used by the cells.

A

38 moles of ATP

107
Q

During glycolysis, glucose is split to form two molecules of ________

A

pyruvic acid

108
Q

Only 2 moles of ATP are formed for each mole of glucose used, which amounts to 24,000 calories of energy stored in the form of ATP.

The total amount of energy lost from the original glucose molecule is 56,000 calories, so the overall efficiency for ATP formation during glycolysis is _________

A

43 percent

109
Q

The remaining _________ of the energy is lost as heat.

A

57 percent

110
Q

after glycolysis, the next stage of degradation of glucose is:

A

Pyruvic Acid Is Converted to Acetyl-Coenzyme A.

111
Q

During this reaction, 2 carbon dioxide molecules 4 four hydrogen atoms are released.

No ATP is formed

A

Pyruvic Acid Is Converted to Acetyl-Coenzyme A.

112
Q

6 molecules of ATP are produced when the 4 hydrogen atoms are later oxidized via the process of

A

oxidative phosphorylation

113
Q

Continued Degradation of Glucose Occurs in
the

A

Citric Acid Cycle

114
Q

Acetyl portion of acetyl-CoA is degraded to carbon dioxide and hydrogen atoms.

Occur in the matrix of mitochondria.

A

Citric Acid Cycle

115
Q

__________released are subsequently oxidized, liberating tremendous amounts of energy to form ATP.

A

Hydrogen atoms

116
Q

No large amount of energy is released during the citric acid cycle,

however; for each molecule of glucose metabolized, _______ molecules of ATP are formed.

A

2

117
Q

Formation of ATP by Oxidation of Hydrogen:
The Process of _________

A

Oxidative Phosphorylation

118
Q

2 ATP molecules are formed in the glycolytic scheme, and another 2 molecules are formed in the citric acid cycle.

A

true

119
Q

Almost __________________ of the total amount of ATP is formed during subsequent oxidation of the hydrogen atoms released during these
early stages of glucose degradation.

A

95 percent

120
Q

The principal function of these earlier stages is to make the __________ of the glucose molecule available in a form that can be used for
oxidation.

A

hydrogen

121
Q

The energy released as the electrons pass through the electron transport chain is used to create a _____________across the inner membrane of the mitochondria.

A

gradient of hydrogen ions

122
Q

The high concentration of hydrogen across the
space is actually what we call as ___________________ across the membrane

A

electron potential difference

123
Q

Hydrogen ions to flow into the mitochondrial matrix through a molecule called ____________

A

ATP synthetase

124
Q

The energy derived from the _________ is used by ATP synthetase to convert adenosine diphosphate (ADP) to ATP.

A

hydrogen ions

125
Q

For each 2 hydrogen atoms ionized by the ETC, up to ____ molecules of ATP are synthesized.

A

3

126
Q

is a sequence of chemical reactions in which
the acetyl portion of the Acetyl Coenzyme A as a product of
glycolysis is degraded towards carbon dioxide and hydrogen atom.

A

Cycle/ Kreb’s cycle

127
Q
A
128
Q

One important way in which ATP helps control energy metabolism is allosteric inhibition of the enzyme ___________.

A

phosphofructokinase

129
Q

phosphofructokinase promotes formation of _________________ during the initial steps of glycolysis.

A

fructose-1,6-diphosphate

130
Q

The net effect of excess cellular ATP is a _______________ to stop glycolysis

Which in turn stops almost all carbohydrate
metabolism

A

feedback mechanism

131
Q

Conversely, ___causes the opposite allosteric change in this enzyme phosphofructokinase

A

ADP

132
Q

The glycolytic process is the set-in motion

➢ When cellular storage of ATP is replenished, the enzyme is again ____________

A

inhibited

133
Q

If oxygen becomes either unavailable or insufficient,
___________ of glucose cannot take place

A

cellular oxidation

134
Q

The process of _______________ is extremely wasteful of glucose because only 24, 000 calories of energy are used to form ATP for each mole of glucose

This is only about 3% of the total energy of the glucose molecule

A

anaerobic glycolysis

135
Q

This release of glycolytic energy to the cells can be
lifesaving measure for a few minutes when oxygen is unavailable -

Meaning if cells are not getting enough blood flow, it can undergo _________________

A

anaerobic glycolysis

136
Q

Allow release of extra anaerobic energy

  • Pyruvic acid and nicotinamide adenine dinucleotide (NADH) -> Lactic dehydrogenase -> lactic acid and NAD+
A

FORMATION OF LACTIC ACID DURING THE PROCESS OF ANAEROBIC GLYCOLYSIS

137
Q

RELEASE OF ENERGY FROM GLUCOSE BY PENTOSE
PHOSPHATE PATHWAY

A

As much as 30% of glucose breakdown in the liver and fat cells is accomplished independent of glycolysis and citric acid cycle

138
Q

Removes 1 carbon atom from a glucose molecule to
produce carbon dioxide and hydrogen during each turn of the cycle

The hydrogen produced eventually enters the oxidative phosphorylation pathway to form ATP

A

PENTOSE PHOSPHATE PATHWAY

139
Q

Formation of carbohydrates from proteins and fats
also occurs in the process of

A

gluconeogenesis

140
Q

When body store of carbohydrate decreases below normal levels, moderate quantities of glucose can be formed from amino acids and the glycerol portion of fat through

A

gluconeogenesis

141
Q

Approximately _____ of the amino acids in the body proteins can be easily converted to carbohydrates, each amino acid is converted to glucose through a slightly different chemical process

A

60%

142
Q

A ___________ and ______________ are the basic stimuli that increase the rate of gluconeogenesis

A

low level of carbohydrates in the cells

decrease in blood glucose

143
Q

in between meals, when fasting, the body maintains glucose using _________________.

A

gluconeogenesis

144
Q

a metabolic pathway to make glucose from amino acids, lactate & glycerol

➢ primarily in liver cells
➢ also happens in epithelial cells of kidney and intestine
➢ specifically, it takes place in the cytoplasm, mitochondria, and ER of the cells

A

GLUCONEOGENESIS

145
Q

2 pathways that can contribute glucose

A
  • Glycogenolysis
  • Gluconeogenesis
146
Q
  • Liver breaks down glycogen into individual glucose
    molecules
  • Only helps on 12-24 hours fasting because glycogen stores are finite
A

GLYCOGENOLYSIS

147
Q
  • Makes glucose from scratch
  • You can keep going if you fast for more than a day - In the 12 hours of fasting, this is the main provider of glucose in the blood stream
A

GLUCONEOGENESIS

148
Q

This process is the reverse of glycolysis

In glycolysis, you’re using 10 enzymatic reactions to
convert glucose to pyruvate to make ATP

In ________________, you’re working backwards, using ATP to convert pyruvate to make glucose

A

gluconeogenesis

149
Q

7 of the reactions in glycolysis and gluconeogenesis
are __________, meaning they can go both in directions using the same enzymes

A

reversible

150
Q

However the other 3 are _________
meaning the enzyme mediating the reaction can only go in the direction of glucose to pyruvate but not in the opposite

A

irreversible (1st, 8th, & 9th)

151
Q

In gluconeogenesis, the 2 main source of pyruvate are:

A
  • lactate
  • amino acids (alanine)
152
Q

byproduct of anaerobic respiration in RBC in exercising skeletal muscle cells

A

Lactate

153
Q

enzyme that removes hydrogen from
lactate turning it to pyruvate

the hydrogen goes to nearby nicotinamide
dinucleotide (NAD+) which turns into NADH

A

Lactate Dehydrogenase

154
Q

building blocks of proteins

  • there are 20 of them - 18 of them (leucine and lysine exemption) are glucogenic amino
    acids, meaning they can make glucose
A

Amino Acid

155
Q

Lazy L’s

A

Leucine and Lysine

156
Q

When fasting for a long time, the body breaks down protein in skeletal muscle cells into individual amino acids with the main
amino acid

A

ALANINE

157
Q

enzyme that removes amino
group from alanine and turns it to pyruvate

the amino group attached to an acid called alpha
ketoglutarate which turns into regular glutamate

A

Alanine Transaminase (ALT)

158
Q

ALT + Pyridoxine (Vitamin B6) is a

A

cofactor

159
Q

When stranded in the woods, your body will start to breaking down fats which come in the form of _________–> ATP

A

triacylglycerides

160
Q

______________ sense blood glucose decreasing so they release glucagon

A

Pancreatic α-cells

161
Q

cause adipocytes or fat cells to stimulate hormone sensitive lipase or HSL (an enzyme that breaks down triacylglycerides into 3 fatty acid and glycerol

A

Low levels of insulin , epinephrine, ACTH

162
Q

enter the bloodstream and hepatocytes mitochondria

and then broken down to AcetylCoA and ATP by Beta-Oxidation.

A

FATE OF FATTY ACIDS

163
Q

used to make glucose in gluconeogenesis.

A

FATE OF GLYCEROL

164
Q

Pyruvate enters the mitochondria and pyruvate carboxylase adds a carbon to it converting it to ______-.

A

oxaloacetate

165
Q

The ____________enhances pyruvate carboxylase activity

A

AcetylCoA

166
Q

3 COFACTORS OF PYRUVATE CARBOXYLASE:

A

1) ATP (from fatty acid oxidation)
2) Biotin
3) Carbon dioxide (CO2)

167
Q

Since oxaloacetate is unable to go out of the mitochondria to continue gluconeogenesis,

___________________ aids by adding hydrogen and converts oxaloacetate to malate (can go out the
mitochondria) and enter the cytoplasm where it is converted by
Malate dehydrogenase back into oxaloacetate.

A

Malate dehydrogenase

168
Q

PEPCK adds a phosphate group to oxaloacetate to turn it into PEP with the energy coming from ________________

A

Guanosine Triphosphate (GTP).

169
Q

enhances the activity of PEPCK by induction, hence
speeding up gluconeogenesis.

A

Stress hormones

170
Q

The goal is for PEP to be converted to ____________________

A

Dihydroxyacetone phosphate/
DHAP.

171
Q

converts G3P to DHAP

A

glycerol-3-phosphate dehydrogenase

172
Q

DHAP is then converted into fructose-1,6
Biphosphate by a reversible reaction catalyzed by the enzyme called

A

aldolase

173
Q

The enzyme Phosphofructokinase-1 (PFK1) adds a phosphate group to fructose-6-phosphate making ______________

A

fructose-1,6-biphosphate.

174
Q

In gluconeogenesis, fructose-1,6-biphosphatase removes a phosphate from the first carbon of fructose-1,6-biphosphate making __________-

A

fructose 6-phosphate (rate-limiting step).

175
Q

Fructose-6-phosphate is converted to its isomer glucose-6 phosphate by the enzyme

A

isomerase

176
Q

-An alternative Oxidative pathway for glucose -Concerned with the synthesis of glucuronic acid, pentoses, and vitamin, ascorbic acid (except in primates and guinea pigs)

-Synthesis of glycosaminoglycans (GAG).

A

URONIC ACID PATHWAY/ GLUCORONIC PATHWAY

177
Q

-highly polar molecule which is incorporated into proteoglycans as
well as combining with bilirubin and steroid hormones.

It can also be combined with certain drugs to increase their solubility.

A

GLUCORONATE

178
Q

normal metabolic intermediate of D-glucuronate breakdown

-enters the Uronic acid pathway to which it can participate in other metabolism

A

DIETARY XYLULOSE

179
Q

EFFECT OF DRUGS ON URONIC ACID PATHWAY

A

Certain drugs like administration of phenobarbital, aminopyrine, antipyrine, chlorobutanol increases uronic acid pathway for synthesis of more glucoronate from glucose for conjugation
purposes

180
Q

Uronic acid of glucose conversion to glucoronate begins with the conversion of glucose-6-phosphate to glucose-1-phosphate by phosphoglucomutase and then activated to UDP-glucose by UDP
glucose phosphorylase.

A

UDP-glucose is oxidized to UDP
glucoronate by NAD with the enzyme UDP-glucose dehydrogenase

Physiology (11 decks)

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