Chemical Century Exam 2

Front 1

What is an example of a way to minimize fat content, how is it made, and how does it act to do so

Back 1

Modified Corn Starch is a fat substitute which is made via a reaction between corn starch, propylene oxide, and phosphorus oxychloride. It acts as a fat substitute by acting as a thickening agent, retaining the original viscosity of the product such as yogurt without the additional fat content.

Front 2

What is an example of a way to minimize caloric content, how is it made, and how does it act to do so

Front 3

What is an example of a semi-synthetic sweetener (One that is a modified version of a product that can be naturally obtained) and describe its characteristics as well as any favorable and unfavorable properties.

Back 3

High Fructose Corn Syrup is obtained via partial hydrolysis of corn starch followed by treatment with glucose isomerase, thereby converting about half of the glucose to fructose. Advantages include ability to be easily used in manufacturing due to its liquid form, high solubility in water, and great availability that is not affected by weather conditions. Disadvantages include concerns that HFCS is a leading cause of obesity in the U.S.

First introduced in the 1970's and quickly became widely used.

Front 4

What is an example of a natural sweetener and describe its characteristics as well as any favorable and unfavorable properties.

Back 4

Sucrose- obtained from processing of sugar cane or sugar beets. Advantages include that it is a natural sugar while disadvantages include that it is high in calorie content.

Front 5

What is an example of a synthetic sweetener and describe its characteristics as well as any favorable and unfavorable properties.

Back 5

-Aspartame

-Functions by interaction with one or more receptor proteins in the "taste buds."

-Tosho Process- enzymatic (thermolysin) formation of the peptide bond using methyl phenylalaninate and racemic aspartic acid- selective for the alpha carboxy group and uses only the natural L-enantiomers

-digested down into natural compounds that are found in other foods but not substantially nutritive.

Advantages: several hundred times sweeter than sucrose, digested to natural compounds

Disadvantages: synthetic which has a negative connotation and is still not accepted by many consumers. PKU individuals can have trouble breaking it down and can lead to mental retardation.

Sold under the brand name "Equal"

-May cause cancer? Studies suggest this given higher dosages of aspartame in rats.

Front 6

Describe the discovery of a class of drugs

Back 6

Beta lactams were discovered by Alexander Fleming in 1928 with his discovery of penicillin when the growth of staphylococcus aureus bacteria was inhibited by a mold. An extract of the mold showed antibiotic properties. Penicillin was then isolated from the extract by a team assembled by Howard Florey (Boris Chain was on the team and he was a biochemist)

Chain and Abraham proposed the four membered cyclic amide ring in 1944, a characteristic of the beta lactams.

Front 7

What is the mechanism of action of the beta lactam class of antibiotics?

Back 7

Beta lactams target the formation of bacterial cells walls by inhibiting the formation of peptidoglycan. They do so by irreversibly binding to penicillin-binding proteins (PBPs) and acylating the serine amino acid in the active site, preventing cross-linking of the peptidoglycan layer.

A method of beta lactam resistance that has developed in bacteria is enzymatic hydrolysis of the beta lactam ring by beta-lactamase.

Front 8

What was the role of biochemists in the discovery and development of vitamins

Back 8

Structure of vitamins such as the structure of vitamin B by Adolf Windaus

Front 9

How does aspirin work?

Back 9

Inhibition of the enzyme cyclooxygenase by acetylsalicylic acid

Front 10

NSAIDS- non steroidal anti-inflammatory drugs

Back 10

Used primarily with people with rheumatoid arthritis because they are more suited to long-term use.

Also causes intestinal bleeding though

Front 11

COXIBS- COX-2 inhibitors

Back 11

Increases the risk of heart attack and stroke but reduces the gastrointestinal issues inherent with aspirin and NSAIDS

Front 12

Maxim-Gilbert Method

Back 12

-Based on selective chemical cleavageNot used anymore

-Slow- method because had to run gels with radioactivity, etc.

Front 13

Sanger Dideoxy Method

Back 13

-All four normal DNA nucleotides; in each of the four tubes, a small amount of one of the dideoxy nucleotides, primer, and DNA polymerase

-The polymerase will add the complementary base but once in a while, it will incorporate the dideoxy version in each tube.

-Stops the synthesis of the strand- spot for every dideoxy base that is introduced

Front 14

Hood Method

Back 14

Added Fluorescence to the Sanger Dideoxy method. Only a single tube was needed and used capillary electrophoresis with a computer read out

Front 15

Celera WGS Shotgun Method

Back 15

Shearing of DNA into many small fragments

Front 16

Pyrosequencing Method

Back 16

1. Shear DNA into many random small fragments

2. Each fragment is captured on a microbead in a miniature well (480 wells/mm^2)

3. Fragments amplified by polymerase chain reactions in microcells

4. DNA bases sequentially passed through the wells

Front 17

Next-Generation Technology

Back 17

1. Library of random fragments created as in Whole Genome Sequencing or Pyrosequencing

2. Fragments are captured on a surface bound by DNA sequences complementary to adapters that have been put in place

3. Sequencing is done by “Reversible Terminator Method"

4. Cycle is repeated, each time adding the next base.

Front 18

How to treat Tuberculosis?

Back 18

Aminiglycosides. Long treatment

Front 19

Three classes of antibiotics

Back 19

Beta lactams

TetracyclinsMarcolides

TetracyclinsMarcolides

Marcolides