Lecture 1: Introduction to Biochemistry

Question 1

showed that urea, a substance of biological origin, could be be synthesized in the laboratory

Answer 1

Friedrich Wöhler

Question 2

within the living thing

Answer 2

in vivo

Question 3

happening outside the living organism

Answer 3

in vitro

Question 4

urea could be synthesized from the inorganic compound

Answer 4

ammonium cyanate

Question 5

turned his attention to fermentation in order to help the French wine
industry

Answer 5

French chemist Louis Pasteur

Question 6

Pasteur recognized that wine could be spoiled by the accidental
introduction of ___ during the fermentation process

Answer 6

bacteria

Question 7

___ cells alone posssess the ability to convert sugars in grapes to ethanol in wine

Answer 7

yeast

Question 8

___ was introduced to prevent spoilage of wine by heating the beverage to kill the bacteria

Answer 8

Pasteurization

Question 9

held that
biological reactions took place
only through the action of a
mysterious “life force” rather
than physical or chemical processes.

Answer 9

vitalism

Question 10

vitalism dogma was shattered by two brothers ___ and __

Answer 10

Eduard and Hans Buchner

Question 11

found that extracts from ____could carry out the entire process of
fermentation of sugar into ethanol.

Answer 11

dead yeast cells

Question 12

Buchner brothers’ study lead to the biochemical analysis in ___

Answer 12

vitro (in glass)

Question 13

biological

catalysts,

Answer 13

enzymes

Question 14

showed that an enzyme from jack beans,
called ____, could be crystallized like any organic
compound and that it consisted entirely of protein

Answer 14

james B.

Sumner,,, urease

Question 15

the discovery of ___ marked the downfall of vitalism

Answer 15

urease

Question 16

control

synthesis of the enzymes involved

Answer 16

gene expression

Question 17

a unit of hereditary information discovered by Gregor Mendel

Answer 17

gene

Question 18

genes must be

found in ___

Answer 18

chromosomes

Question 19

Nucleic acids had been recognized

as cellular constituents since their discovery in 1869 by ____

Answer 19

Friedrich

Miescher

Question 20

the early 1900s nucleic acids were thought to be simple substances,
fit only for _____ in the cell. Most biochemists believed that
only _____ were sufficiently complex to carry genetic information.

Answer 20

structural roles’’’’ proteins

Question 21

Experiments in the 1940s

and early 1950s proved conclusively that ____ is the primary bearer of genetic information

Answer 21

deoxyribonucleic acid

DNA

Question 22

____ is also an informational molecule

Answer 22

ribonucleic

acid, RNA,

Question 23

described the doublehelical

structure of DNA

Answer 23

James Watson and Francis Crick

Question 24

Evolution of biochemistry summary

Answer 24

doctrine of vitalism > wohler’s synthesis of urea > discovery of fermentation > cell-free enzymatic reactions > elucidation of enzyme structure > existence of genes > discovery of DNA > DNA as a genetic material > DNA double helix > Central dogma of molecular biology > rise of biotechnology

Question 25

the most abundant elements are called ___

Answer 25

1st tier elements

Question 26

____, 1st tier elements, are important | to life because of their strong tendencies to form ___ bonds

Answer 26

C H O N ,,,, covalent

Question 27

the ____ of carbon–carbon bonds and the possibility of forming single, double, or triple bonds give carbon the versatility to be part of an enormous diversity of chemical compounds

Answer 27

stability

Question 28

___ of essential elements includes sulfur and phosphorus, which form covalent bonds, and the ions Na+, K+, Mg2+, Ca2+, and Cl-.

Answer 28

“second tier”

Question 29

Second tier element includes ___

Answer 29

sulfur and phosphorus

Question 30

Sulfur is a constituent of nearly all ____,

Answer 30

proteins

Question 31

phosphorus plays essential roles in ___ and the structure of ___.

Answer 31

energy metabolism,,, nucleic acids

Question 32

third- and fourth-tier elements are metals, some of which serve as aids to the ____

Answer 32

catalysis of biochemical reactions

Question 33

Many biochemists believe that the earliest primitive systems, capable of self-replication and some form of metabolism, were based on ____.

Answer 33

ribonucleic | acid (RNA)

Question 34

___ are giant molecules made up of smaller | organic molecule subunits

Answer 34

Biological macromolecules

Question 35

in living organisms there are ___ major | classes of macromolecules,

Answer 35

four

Question 36

list the major classes of macromolecules

Answer 36

proteins, nucleic acids, carbohydrates, and lipids

Question 37

if the DNA molecules in a single human cell | were stretched end to end, they would reach a length of about __

Answer 37

2 meters

Question 38

These biopolymers are made by joining | together prefabricated units, called ____

Answer 38

monomers

Question 39

Of the four classes of | macromolecules, ___ of them are biopolymers

Answer 39

three

Question 40

list the biopolymers

Answer 40

proteins, nucleic acids, | and carbohydrates

Question 41

true or false: lipids are not biopolymers

Answer 41

true

Question 42

simple example is the carbohydrate | ___, a major constituent of the cell walls of plants.

Answer 42

cellulose

Question 43

Cellulose is a polymer made by joining thousands of molecules of _____

Answer 43

glucose

Question 44

Covalent links between glucose units are formed by removing a water molecule between two adjoining glucose molecules, ____

Answer 44

condensation

Question 45

true or false: all chemical linkages in this molecule are identical NAMED: ___

Answer 45

true;; glycosidic linkage

Question 46

Because cellulose is a polymer | of a simple sugar, or saccharide, it is called a ___

Answer 46

polysaccharide

Question 47

a type of polymer that is constructed from identical monomeric units is called a ____

Answer 47

homopolymer

Question 48

many polysaccharides—and | all nucleic acids and proteins—are ____, a type of polymer

Answer 48

heteropolymers,

Question 49

Nucleic acids are polymers made up of four | ___

Answer 49

nucleotides

Question 50

nucleic acids are also called ___

Answer 50

polynucleotides.

Question 51

proteins are assembled from combinations of | 20 different ____

Answer 51

amino acids.

Question 52

Protein chains are called ___, a term derived from the ____ that joins two amino acids together.

Answer 52

polypeptides;; peptide | bond

Question 53

list protein diverse biological functions and site an example

Answer 53

``` Structural- keratin and collagen Transport- hemoglobin Signalling- hormones, receptors Immunity- antibodies Catalysis- enzymes ```

Question 54

___catalyzes | the joining of nucleotide molecules to synthesize RNA

Answer 54

RNA polymerase

Question 55

nucleotides are connected by ____ bonds

Answer 55

phosphodiester bonds

Question 56

true or false: lipids have low solubility in the aqueous | environment of the cell.

Answer 56

true

Question 57

lipids function is to serve as the major ___ element of the membranes that surround cells and partition them into various compartments

Answer 57

structural

Question 58

___ formerly called triglycerides, are esters

Answer 58

Triacylglycerols

Question 59

Triacylglycerols are formed by condensation between the three hydroxyl groups of __and three long-chain ___

Answer 59

glycerol ;;; fatty acids

Question 60

Phospholipids are ____meaning that they have both hydrophobic and hydrophilic functional groups

Answer 60

amphipathic

Question 61

phospholipids have ____, cluster on the outside, in contact with the watery milieu.

Answer 61

polar head