Biochemistry

Question 1

What is the empirical formula of the Human DNA?

Answer 1

C39 H50 O22 N15 P3

Question 2

A two dimensional representation showing the configuration of a stereocenter; horizontal lines represent bonds projecting forward from the stereocenter, and vertical lines represent bonds projecting toward the rear.

Answer 2

Fischer projection

Question 3

A monosaccharide that, when written as a Fischer projection, has the -OH group on its penultimate carbon to the right.

Answer 3

D-Monosaccharide

Question 4

A monosaccharide that, when written as a Fischer projection, has the -OH group on its penultimate carbon to the left.

Answer 4

L-Monosaccharide

Question 5

A monosaccharide in which an -OH group is replaced by an -NH2 group.

Answer 5

Amino Sugar

Question 6

A way to view furanose and pyranose forms of monosaccharides; the ring is drawn flat and viewed through its edge, with the anomeric carbon on the right and the oxygen atom to the rear.

Answer 6

Haworth projection

Question 7

The hemiacetal carbon of the cyclic form of a monosaccharide.

Answer 7

Anomeric Carbon

Question 8

Monosaccharides that differ in configuration only at their anomeric carbons.

Answer 8

Anomers

Question 9

A five-membered cyclic hemiacetal form of a monosaccharide.

Answer 9

Furanose

Question 10

A six-membered cyclic hemiacetal form of a monosaccharide.

Answer 10

Pyranose

Question 11

Most prevalent forms of D-ribose and other pentoses in the biological world.

Answer 11

Furanoses

Question 12

For pyranoses, the six membered ring is more accurately reperesented as a

Answer 12

chair conformation

Question 13

The change in specific rotation that occurs when a or B of a carbohydrate is converted to an equilibrium mixture of the two forms.

Answer 13

Mutarotation

Question 14

A carbohydrate in which the -OH group on its anomeric carbon is replaced by an -OR group.

Answer 14

Glycoside

Question 15

Cyclic acetal derived from a monosaccharide is called

Answer 15

glycoside

Question 16

The bond from the anomeric carbon of a glycoside to an -OR group.

Answer 16

Glycosidic bond

Question 17

The product formed when the CHO group of a monosaccharide is reduced to CH2OH group.

Answer 17

Alditol

Question 18

It is found in the plant world in many berries and in cherries, plums, pears, apples, seaweed, and algae. It is about 60% as sweet as table sugar (sucrose) and is used in the manufacture of candies and as a sugar substitute for diabetics.

Answer 18

Sorbitol

Question 19

It is used as a sweetening agent in “sugarless” gum, candy, and sweet cereals.

Answer 19

Xylitol

Question 20

A carbohydrate that reacts with a mild oxidizing agent under basic conditions to give an aldonic acid; the carbohydrate reduces the oxidizing agent.

Answer 20

Reducing sugar

Question 21

Serves as an important component of the acidic polysaccharides of connective tissues.

Answer 21

D-glucuronic acid

Question 22

Used by the body to detoxify foreign phenols and alcohols.

Answer 22

D-glucuronic acid

Question 23

In the liver, these compounds are converted to glycosides of glucuronic acid (glucuronides) and extcreted in the urine.

Answer 23

D-glucuronic acid

Question 24

Who discovered the ABO blood group system?

Answer 24

Karl Landsteiner

Question 25

A carbohydrate containing two monosaccharide units joined by a glycosidic bond.

Answer 25

Disaccharide

Question 26

A carbohydrate containing from six to ten monosaccharide units, each joined next by a glycosidic bond.

Answer 26

Oligosaccharide

Question 27

A carbohydrate containing a large number of monosaccharide units, each joined to the next by one or more glycosidic bonds.

Answer 27

Polysaccharide

Question 28

Three most important disaccharides

Answer 28

Sucrose, Lactose, Maltose

Question 29

The sweetest disaccharide sweetener

Answer 29

D-fructose

Question 30

Molecular weight of Cellulose

Answer 30

400,000 g/mol

Question 31

Enzyme that catalyze the hydrolysis of B-glucosidic bonds.

Answer 31

B-glucosidases

Question 32

Small polysaccharides resulted from the break down of corn starch.

Answer 32

Dextrins

Question 33

Triesters of glycerol and long chain carboxylic acids called fatty acids.

Answer 33

Triglycerides

Question 34

A mixture of triglycerides containing a high proportion of long-chain, saturated fatty acids.

Answer 34

Fat

Question 35

A mixture of triglycerides containing a high proportion of long-chain, unsaturated fatty acids.

Answer 35

Oil

Question 36

Classification of complex lipids

Answer 36

Phospholipids and Glycolipids

Question 37

It contains alcohol, two fatty acids, and a phosphate group.

Answer 37

Phospholipids

Question 38

Two types of phospholipids

Answer 38

Glycerophospholipids and Sphingolipids

Question 39

A phospholipid where the alcohol is a glycerol.

Answer 39

Glycerophospholipids

Question 40

A phospholipid whose alcohol is sphingosine.

Answer 40

Sphingolipids

Question 41

Complex lipids that contain carbohydrates.

Answer 41

Glycolipids

Question 42

Complex lipids that contain ceramides

Answer 42

Sphingomyelin, sphingolipids, cerebroside glycolipids

Question 43

Hydrophilic functional groups of glucocerebroside

Answer 43

carbohydrate, hydroxyl and amide groups of the cerebroside

Question 44

Hydrophilic functional groups of Sphingomyelin

Answer 44

phosphate group, choline, hydroxyl and amide of ceramide

Question 45

Where can pure cholesterol crystals be found in the body?

Answer 45

Gallstones, joints of people suffering from bursitis

Question 46

What are the structural features common to oral contraceptives, including mifepristone?

Answer 46

steroid ring structure, methyl group at carbon 13, triple bonded group at carbon 17, some unsaturation in the A ring, the B ring, or both.

Question 47

What are coated pits? What is their function?

Answer 47

Coated pits are concentrations of LDL receptors on the surface of cells. They bind LDL and by endocytosis transfer it inside the cell.

Question 48

What is the major difference between aldosterone and the other hormones?

Answer 48

Aldosterone has an aldehyde group at carbon 13?

Question 49

How many grams of H2 are needed to saturate 100 g of a triglyceride made of glycerol and one unit of lauric, oleic, and linoleic acids?

Answer 49

0.72 g hydrogen gas

Question 50

Which substances would you expect to consist primarily of carbohydrates and which primarily of lipids: olive oil, butter, cotton, cotton candy?

Answer 50

Primarily lipid: olive oil and butter Primarily carbohydrate: cotton and cotton candy