Chem 2B Ch. 11 Carbohydrate Metoboism

Front 1

Glucose is converted into _______ for entrance into the Citric acid cycle.

Back 1

Acetyl-CoA

Front 2

α-amylase catalyses the hydrolysis of the ______ bonds of the carbohydrates:

Back 2

α-glycosidic bonds int he carbs: amylose and amylopectin

Front 3

Starches from plants and glycogen from meat are hydrolyzed to give:

Back 3

smaller polysaccharides and the disaccharide maltose

Front 4

α-amylose continues to act on polysaccharides until:

Back 4

it is deactivated by stomach acid.

Front 5

Carbohydrate digestion ceases in the:

Back 5

stomach

Front 6

α-amylose is secreted by the:
and conversion of polysaccharides to maltose continues in the:

Back 6

pancrease; small intestine

Front 7

When glucose enters a cell it is immediately converted into:

Back 7

glucose 6-phosphate

Front 8

Once glucose is converted to glucose 6-phosphate, it is trapped inside the cell because:

Back 8

phosphorylated molecules cannot cross the cell membrane.

Front 9

Once glucose 6-phosphate is produced, what are all the pathways it can follow?

Back 9

there are 3:
-Glycolysis
-Glycogenesis
-Pentose Phosphate pathway

Front 10

Describe Glycolysis:

Back 10

When energy is needed, glucose 6-phosphate is turned into Pyruvate, which is catalyzed by Pyruvate dehydrogenase to yield Acetyl-CoA, which then enters the Citric Acid Cycle.

Front 11

Describe Glycogenesis:

Back 11

When cells are already well supplied with glucose, excess glucose 6-phosphate is converted into glycogen for storage.

Front 12

Describe the Pentose Phosphate Pathway:

Back 12

This multi-step pathway yields two products important to metabolism: NADPH and ribose 5-phosphate (essential for synthesis of nucleic acids).

Front 13

What are the two reactions that produce Glucose from storage?

Back 13

Gluconeogenesis and Glycogenolysis.

Front 14

Describe Gluconeogenesis:

Back 14

Glucose is synthesized from amino acids, pyruvate, and other non-carbohydrates.

Front 15

Describe Glycogenolysis:

Back 15

Glucose is synthesized from the breakdown of glycogen.

Front 16

Describe Glycolysis:

Back 16

A series of 10 enzyme catalyzed reactions that converts each glucose molecule into two pyruvate molecules, and yields two ATP molecules and two NADH molecules.

Front 17

The biochemical pathway that breaks down a molecule of glucose into two molecules of pyruvate plus energy.

Back 17

Glycolysis

Front 18

Describe step 1 of glycolysis:

Back 18

Glucose reacts with ATP to yield glucose 6-phosphate plus ADP in a reaction catalyzed by hexokinase.

Front 19

Describe step 2 of glycolysis:

Back 19

glucose 6-phosphate is isomerized to yield fructose 6-phosphate in a reaction catalyzed by glucose 6-phosphate isomerase.

Front 20

Describe step 3 of glycolysis:

Back 20

Fructose 6-phosphate reacts with a second molecule of ATP to yield fructose 1,6-biphosphate plus ADP in a reaction catalyzed by phosphofructokinase.

Front 21

Describe step 4 of glycolysis:

Back 21

The six-carbon chain of fructose 1,6-bishphosphate is cleaved into two, three-carbon pieces by the enzyme aldolase.

Front 22

Describe step 5 of glycolysis:

Back 22

The two products of step 4 are both three-carbon sugars, but only glyceraldehyde 3-phosphate can continue in the glycolysis pathway. Dihydroxyacetone phosphate must first be isomerized by the enzyme triose phosphate isomerase.

Front 23

Describe step 6 of glycolysis:

Back 23

Two reactions occur as glyceraldehyde 3-phosphate is first oxidized to a carboxylic acid and then phosphorylated by the enzyme glyceraldehyde 3-phosphate dehydrogenase. The coenzyme NAD⁺ and inorganic phosphate ion (HOPO₃²⁻) are required.

Front 24

Describe step 7 of glycolysis:

Back 24

A phosphate group from 1,3-bisphosphoglycerate is transferred to ADP, resulting in synthesis of ATP, and catalyzed by phosphoglycerate kinase.

Front 25

Describe step 8 of glycolysis:

Back 25

A phosphate group is next transferred from carbon 3 to carbon 2 of phosphoglycerate in a reaction catalyzed by phosphoglycerate mutase.

Front 26

Describer step 9 of glycolysis:

Back 26

Loss of water from 2-phosphoglycerate produces phosphoenolpyruvate (PEP). The dehydration is catalysed by the enzyme enolase.

Front 27

Describe step 10 of glycolysis:

Back 27

Transfer of the phosphate group from phosphoenolpyruvate to ADP yields pyruvate and generates ATP, catalyzed by pyruvate kinase.

Front 28

In what two ways is fructose converted to glycolysis intermediates?

Back 28

1) in muscle, it is phosphorylated to fructose 6-phosphate
2) in the liver, it is converted to glyceraldehyde 3-phosphate.

Front 29

What is galactose converted into?

Back 29

glucose 6-phosphate

Front 30

What is mannose converted into?

Back 30

first mannose 6-phosphate (by hexokinase), then fructose 6-phosphate.

Front 31

Under aerobic conditions, pyruvate is converted to:
Under anaerobic conditions, pyruvate is converted to:

Back 31

acetyl-CoA
lactate

Front 32

When oxygen becomes available again, lactate can be converted back to pyruvate by:

Back 32

muscle cells

Front 33

Lactate can be converted to glucose by:

Back 33

the liver via the Cori cycle

Front 34

Pyruvate can be converted back to glucose in the liver via:

Back 34

gluconeogenesis

Front 35

What is the net product of one glucose from Glycolysis?

Back 35

2 Pyruvates
2 NADH
2ATP

Front 36

What is the net product of one glucose from Pyruvate oxidation?

Back 36

2 Acetyl-CoA
2 CO₂
2NADH

Front 37

What is the net product of one glucose from the Citric Acid Cycle?

Back 37

6 NADH
2 FADH₂
2 ATP
4 CO₂

Front 38

What is the total net products of one glucose from Gylcolysis and the Citric Acid Cycle?

Back 38

10 NADH
2 FADH₂
4 ATP
6 CO₂

Front 39

Normal blood glucose is:

Back 39

65 - 100mg/dL

Front 40

Consciousness is impaired or lost around a blood glucose of:

Back 40

30mg/dL

Front 41

The fasting blood glucose level diagnostic for diabetes is:

Back 41

≥ 140mg/dL

Front 42

The two hormones that have the major responsibility for blood glucose regulation are:

Back 42

insulin and glucagon

Front 43

What does glucagon do?

Back 43

It is released when blood glucose levels fall; stimulates glycogen breakdown and glucose release by the liver.

Front 44

List the order of glucose production in the metabolism of starvation and fasting.

Back 44

1) glycogen from muscles and liver is used.
2) gluconeogenesis
3) lipid breakdown; use of ketone bodies.

Front 45

The biochemical pathway for synthesis of glycogen, a branched polymer of glucose.

Back 45

Glycogenesis

Front 46

The biochemical pathway for breakdown of glycogen to free glucose.

Back 46

Glycogenolysis

Front 47

The biochemical pathway for the synthesis of glucose from non-carbohydrates, such as lactate, amino acids, or glycerol.

Back 47

Gluconeogenesis

Front 48

Describe the Cori cycle:

Back 48

Lactate absorbed from the blood is converted to pyruvate which the liver turns into glucose.