Carbs Lab Manual

Question 1

Carbohydrates can be grouped into generic classifications based on the number of carbons in the molecule. For example,____ contain three carbons,_____ contain four,_____ contain five, and_____ contain six.

Answer 1

trioses

tetroses

pentoses

hexoses

Question 2

the smallest carbohydrate is_______, a three-carbon compound.

Answer 2

glyceraldehyde

Question 3

Carbohydrates are hydrates of _________ derivatives based on the location of the CO functional group.

Answer 3

aldehyde or ketone

Question 4

The two forms of carbohydrates are

Answer 4

aldose and ketose

Question 5

The______ form has a terminal carbonyl group (O=CH) called an_____ group

Answer 5

aldose

aldehyde group

Question 6

The_____ form has a carbonyl group (O=C) in the middle linked to two other carbon atoms (called a_____ group).

Answer 6

ketose

ketone group

Question 7

Another classification of carbohydrates is based on number of sugar units in the chain:

Answer 7

monosaccharides
disaccharides
oligosaccharides
polysaccharides

Question 8

chaining of sugars relies on the formation of_____ bonds that are bridges of oxygen atoms.

Answer 8

glycosidic bonds

Question 9

When two carbohydrate molecules join, a_____ molecule is produced.

Answer 9

water

Question 10

When they split, one molecule of water is used to form the individual compounds. This reaction is called______.

Answer 10

hydrolysis

Question 11

are simple sugars that cannot be hydrolyzed to a simpler form.

These sugars can contain three, four, five, and six or more carbon atoms (known as trioses, tetroses, pentoses, and hexoses, respectively).

The most common include (3)

Answer 11

Monosaccharides

glucose, fructose, and galactose

Question 12

are formed when two monosaccharide units are joined by a glycosidic linkage.

Answer 12

Disaccharides

Question 13

On hydrolysis,_______ will be split into two monosaccharides by disaccharide enzymes (e.g., lactase) located on the microvilli of the intestine.

These monosaccharides are then actively absorbed.

Answer 13

disaccharides

Question 14

The most common disaccharides are (3)

Answer 14

maltose
lactose
sucrose

Question 15

Oligosaccharides are the chaining of ____-_____ sugar units, whereas_____ are formed by the linkage of many monosaccharide units.

Answer 15

2 to 10

polysaccharides

Question 16

On hydrolysis, polysaccharides will yield more than____ monosaccharides.

Answer 16

10

Question 17

_____hydrolyzes starch to disaccharides in the duodenum.

Answer 17

Amylase

Question 18

The most cornmon polysaccharides are____ (glucose molecules) and____.

Answer 18

starch

glycogen

Question 19

is a primary source of energy for humans.

Answer 19

Glucose

Question 20

The nervous system, including the brain, totally depends on_____ from the surrounding extracellular fluid (ECF) for energy.

Answer 20

glucose

Question 21

——-cannot concentrate or store carbohydrates; therefore, it is critical to maintain a steady supply of glucose to the tissue. For this reason, the concentration of glucose in the ECF must be maintained in a narrow range.

Answer 21

Nervous tissue

Question 22

When the_______ concentration falls below a certain level, the nervous tissues loose the primary energy source and are incapable of maintaining normal function.

Answer 22

glucose

Question 23

The first step for all three pathways requires glucose to be converted to glucose-6-phosphate using the high energy molecule, ATP.

This reaction is catalyzed by the enzyme______.

Answer 23

hexokinase

Question 24

Glucose-6-phosphate can enter the (3)

Answer 24

Embden-Meyerhof-Parnas Pathway (EMP Pathway) or…

hexose monophosphate pathway or…

can be converted to glycogen

Question 25

important for the generation of energy from glucose (2)

Answer 25

Embden-Meyerhof-Parnas Pathway (EMP Pathway) or the hexose monophosphate pathway

Question 26

is important for the storage of glucose.

Answer 26

glycogen pathway

Question 27

In the EMP Pathway, glucose is broken down into two, three-carbon molecules of______ that can enter the tricarboxylic acid cycle (TCA cycle) on conversion to acetyl-coenzyme A (acetyl-CoA). This pathway requires oxygen and is called the______

Answer 27

pyruvic acid aerobic pathway

Question 28

______ is the name for the conversion of glucose to glycogen, the most important storage polysaccharide in (2)

Answer 28

Glycogenesis liver and muscle

Question 29

the breakdown of glycogen to glucose and other intermediate products, is termed________.

Answer 29

glycogenolysis

Question 30

The formation of glucose from non-carbohydrate sources, such as amino acids, glycerol, or lactate, is termed_______.

Answer 30

gluconeogenesis

Question 31

The conversion of glucose or other hexoses into lactate or pyruvate is called_______.

Answer 31

glycolysis

Question 32

______is the primary hormone responsible for the entry of glucose into the cell. It is synthesized by the cells of ______ in the _____

Answer 32

Insulin islets of Langerhans in the pancreas

Question 33

When these cells detect an ***increase in body glucose***, they ***release insulin.*** The release of insulin causes an increased movement of glucose into the cells and ***increased glucose metabolism.***

Answer 33

Cells of islets of Langerhans in the pancreas

Question 34

______is a 29-amino-acid polypeptide secreted by the_____ cells of the pancreas.

Answer 34

Glucagon ***a cells***

Question 35

The maior target organ for glucagon is the______, where it binds to specific receptors and increases intracellular adenosine 5'-monophosphate (AMP) and calcium.

Answer 35

liver

Question 36

Glucagon stimulates the production of glucose in the liver by (2)

Answer 36

glycogenolysis and gluconeogenesis

Question 37

enhances ketogenesis in the liver.

Answer 37

glucagon

Question 38

A minor target organ for glucagon is_______, where the hormone increases lipolysis.

Answer 38

adipose tissue

Question 39

_______ is actually a group of metabolic diseases characterized by ***hyperglycemia*** resulting from defects in insulin secretion, insulin action, or both.

Answer 39

Diabetes mellitus

Question 40

In 1979, the________ developed a classification and diagnosis scheme for diabetes mellitus. This scheme included dividing diabetes into two broad categories: (2)

Answer 40

National Diabetes Data Group type 1 type 2

Question 41

insulin-dependent diabetes mellitus (IDDM)

Answer 41

type 1

Question 42

non-insulin-dependent diabetes mellitus (NIDDM)

Answer 42

type 2

Question 43

Type 1 diabetes mellitus was formerly known as

Answer 43

IDDM type I juvenile-onset diabetes

Question 44

Approximately ______ of all individuals with diabetes mellitus are type 1

Answer 44

5% to 10%

Question 45

T1D Symptoms

Answer 45

(e.g., polyuria, polydipsia, and rapid weight loss) usually present acutely;

Question 46

T1D individuals have_______ (a deficiency of insulin) because of loss of pancreatic islet fi-cells and depend on insulin treatment to sustain life and prevent ketosis. Most individuals have antibodies that identify an autoimmune process.

Answer 46

insulinopenia

Question 47

is characterized by hyperglycemia as a result of an individual's ***resistance to insulin*** with an insulin secretory defect. This resistance results in a relative, not an absolute, insulin deficiency.

Answer 47

Type 2 diabetes mellitus

Question 48

Type____ constitutes the majority of the diabetes cases. Most patients in this type are obese or have an increased percentage of body fat distribution in the abdominal region.

Answer 48

T2D

Question 49

This type of diabetes often goes undiagnosed for many years and is associated with a strong genetic predisposition, with patients at increased risk with an increase in age, obesity, and lack of physical exercise. Characteristics usually include adult onset of the disease and milder symptoms than in type 1, with_____ seldom occurring.

Answer 49

T2D ketoacidosis

Question 50

involves ***decreased plasma glucose levels*** and can have many causes--some are transient and relatively insignificant, but others can be life threatening.

Answer 50

Hypoglycemias

Question 51

Hypoglycemia The most widely used cutoff is___ mg/dL, but some authors suggest____ mg/dL.

Answer 51

50 60

Question 52

Hypoglycemia A transient decline may occur ______ hours after a meal, and it is not uncommon for plasma glucose concentration as low as ____mg/dL to be observed 2 hours after ingestion of an oral glucose load. Similarly, extremely low fasting blood glucose values may be occasionally noted without symptoms or evidence of underlying disease.

Answer 52

1.5 to 2 50

Question 53

______produces the classic signs and symptoms of hypoglycemia, namely trembling, sweating, nausea, rapid pulse, lightheadedness, hunger, and epigastric discomfort.

Answer 53

Epinephrine

Question 54

The most common methods of glucose analysis use the enzyme (2)

Answer 54

***glucose oxidase*** or ***hexokinase***

Question 55

is the ***most specific enzyme*** reacting with only b-D-glucose.

Answer 55

Glucose oxidase

Question 56

Glucose oxidase converts B-D-glucose to______

Answer 56

gluconic acic

Question 57

_______may be added to the reaction to facilitate the conversion of a-D-glucose to B-D-glucose. Oxygen is consumed and hydrogen peroxide (H202) is produced.

Answer 57

Mutarotase

Question 58

***Horseradish peroxidase*** is used to catalyze the second reaction, and the H202 is used to oxidize a dye compound. Two commonly used chromogens are (2). The shift in absorbance can be monitored_______ and is proportional to the amount of glucose present in the specimen. This coupled reaction is known as the______ reaction.

Answer 58

3-methyl-2-benzothiazolinone hydrazone and N, N-dimethylaniline spectrophotometrically Trinder reaction

Question 59

The_______ method is considered ***more accurate*** than the glucose oxidase methods because the coupling reaction using glucose-6-phosphate dehydrogenase is highly specific; therefore, it has less interference than the coupled glucose oxidase procedure. _______ in the presence of ATP converts glucose to glucose-6-phosphate.

Answer 59

hexokinase

Question 60

Glucose-6-phosphate and the cofactor NAD are converted to 6-phosphogluconate and NADPH by ____ (enzyme) NADPH has a strong absorbance maximum at______, and the rate of appearance of NADPH can be monitored_______ and is proportional to the amount of glucose present in the sample.

Answer 60

glucose-6-phosphate dehydrogenase 340 nm spectrophotometrically

Question 61

*^$Nonspecific methods*** of measuring glucose are still used in the_____ section of the laboratory primarily to detect reducing substances other than glucose. The method given next is the Benedict's modification, also called the______ reaction.

Answer 61

urinalysis Clinitest reaction