BIOCHEM - MIDTERM

Question 1

Which of the following is not a pentose?

Answer 1

FRUCTOSE

Question 2

A Polysaccharide which is often called animal starch is

Answer 2

GLYCOGEN

Question 3

Interconversion of α form to β form

Answer 3

MUTAROTATION

Question 4

Which is NOT characteristic of the genetic code?

Answer 4

OVERLAPPING

Question 5

What causes formation of highly reactive free radicals in the DNA?

Answer 5

X-RAY

Question 6

The removal of incorrect nucleotides immediately after they are added to the growing DNA during replication is known as

Answer 6

PROOFREADING

Question 7

How many possible codons code for amino acids?

Answer 7

61

Question 8

In DNA extraction, which of the following chemicals dissolve the membrane components of the cell?

Answer 8

DETERGENTS

Question 9

What strand of the DNA has the gene base sequence that specifies the amino acid sequence of a protein?

Answer 9

SENSE STRAND

Question 10

With regards to the Michaelis-Menten equation, a molecule that has the effect of increasing the Vmax start text, end text, start subscript, m, a, x, end subscript of a reaction upon binding to an enzyme would be called what?

Answer 10

ACTIVATOR

Question 11

What repair mechanism involves photolyase, which removes the covalent bond between pyrimidine dimmers?

Answer 11

LIGHT REPAIR

Question 12

What is the linkage that is formed when two monosaccharides react to form a disaccharide?

Answer 12

GLYCOSIDIC LINKAGE (because,
monosaccharides)

Question 13

What repair mechanism must recognize the methylated DNA strand to properly repair an error in DNA base pairing?

Answer 13

MISMATCH REPAIR

Question 14

In DNA extraction, addition of lysis solution will:

Answer 14

ELIMINATE PROTEINS AND LIPIDS

Question 15

These sugars cannot be hydrolyzed into simpler carbohydrates

Answer 15

MONOSACCHARIDES

Question 16

What feature does a carbohydrate possessed that generates stereoisomerism?

Answer 16

PRESENCE OF CHIRAL CENTER

Question 17

RNA splicing is involved in

Answer 17

REMOVAL OF INTRONS IN THE PRIMARY TRANSCRIPT

Question 18

Which of the following is a mismatch?

Answer 18

TEMPLATE – DOUBLE STRANDED DNA (ALL THROUGHOUT THE REACTION)

Question 19

Which of the following compounds IS NOT considered as an irreversible inhibitor?

Answer 19

METHOTREXATE

Question 20

Primer used for the process of polymerase chain reaction are ()

Answer 20

SINGLE STRANDED DNA OLIGONUCLEOTIDE

Question 21

A solution that contains DNA fragments of known lengths in base pairs.

Answer 21

DNA LADDER

Question 22

The DNA or RNA used in a PCR reaction serves as the:

Answer 22

TEMPLATE

Question 23

What sugar is the major metabolic fuel of mammals?

Answer 23

GLUCOSE

Question 24

What is the major difference between glucose and fructose?

Answer 24

TYPE OF CARBONYL FUNCTIONAL GROUP

Question 25

What are the two different glucose- containing polysaccharides can be isolated from starch?

Answer 25

AMYLOSE; AMYLOPECTIN

Question 26

The monosaccharide units are linked by α 1- 4 glycosidic linkage in

Answer 26

MALTOSE

Question 27

Which of the following describes the relationship between the linear forms of D- glucose and D-galactose that differ only in stereochemical configuration at the fourth carbon?

Answer 27

THEY ARE EPIMERS

Question 28

Which is NOT a modification that occurs after synthesis of a polypeptide?

Answer 28

ADDITION OF A 5’ CAP

Question 29

What enzyme classes catalyze reactions in which two molecules become dissociated from each other?

Answer 29

HYDROLASE

Question 30

Which of the statements regarding enzymes is UNACCEPTABLE?

Answer 30

ENZYME ACTIVITY CANNOT BE REGULATED

Question 31

It is the simplest sugar

Answer 31

DEHYDROXYACETONE

Question 32

What RNA is NOT involved in the translation process?

Answer 32

snRNA

Question 33

The genetic code is found in

Answer 33

mRNA

Question 34

In RNA synthesis, the DNA template must be separated. Which of the following separates the DNA strands?

Answer 34

SIGMA SUBUNIT OF RNA POLYMERASE

Question 35

In a cyclic structure, this linkage is formed by reacting the aldehyde group and a hydroxyl group

Answer 35

HEMIACETAL

Question 36

The anticodon is found in

Answer 36

tRNA

Question 37

Which statement is true?

Answer 37

IN EUKARYOTES, THERE IS EVIDENCE THAT RIBOSOMES ARE PRESENT IN THE NUCLEUS

Question 38

Penicillin is an example of what type of enzyme inhibitor?

Answer 38

IRREVERSIBLE

Question 39

What stains can be used to visualize DNA gel electrophoresis band?

Answer 39

ANY FLUORESCENT DYE THAT HAS AFFINITY WITH DNA

Question 40

What eliminates protein in the sample during DNA extraction?

Answer 40

PROTEINASE K

Question 41

Which is INCORRECT regarding transcription in prokaryotes?

Answer 41

DNA PRIMER IS USED INSTEAD OF RNA PRIMER

Question 42

The part of the enzyme where the substrate binds is called the:

Answer 42

ACTIVE SITE

Question 43

When DNA copies are multiplied at a rapid rate, this is referred to as () amplification.

Answer 43

EXPONENTIAL

Question 44

An amylose polymer and a glycogen polymer, each containing 100 monosaccharide subunits, are cleaved completely by an enzyme. How many individual glucose molecules are created during this process?

Answer 44

200

Question 45

Which of the following is TRUE for D- and L- isomerism?

Answer 45

The orientation of the -OH groups at the highest numbered chiral determines whether the sugar belongs to the D or L series.

Question 46

The first aminoacyl-tRNA that binds the ribosome during protein synthesis in prokaryotes is:

Answer 46

fmet – tRNA

Question 47

Which is INCORRECT concerning RNA polymerase in prokaryotes?

Answer 47

The sigma subunit is responsible for the termination of transcription

Question 48

What enzyme activates amino acids prior to protein synthesis?

Answer 48

AMINO ACYL – tRNAsynthetase

Question 49

It is a protein molecule that has one or more carbohydrate units covalently bonded to it

Answer 49

GLYCOPROTEIN

Question 50

What enzyme classes catalyze reactions in which two molecules are covalently connected to each other?

Answer 50

LIGASE

Question 51

Which is INCORRECT regarding RNA synthesis in eukaryotes?

Answer 51

ONLY ONE RNA POLYMERASE IS INVOLVED

Question 52

The -10 region of prokaryotic promoter is also known as

Answer 52

PRIBNOW BOX

Question 53

Which of the following is TRUE regarding the polysaccharides glycogen and cellulose?

Answer 53

ONLY GLYCOGEN MOLECULES HAVE BRANCHING REGIONS

Question 54

Which of the following statements is true about migration of biomolecules?

Answer 54

RATE OF MIGRATION IS DIRECTLY PROPORTIONAL TO CURRENT

Question 55

Termination of transcription is facilitated by

Answer 55

RHO PROTEIN

Question 56

The relationship between an enzyme and a substrate molecule can best be described as:

Answer 56

A TEMPORARY ASSOCIATION

Question 57

Which carries the amino-acid to the ribosomes during protein synthesis?

Answer 57

tRNA

Question 58

The basic steps in protein synthesis are the same for both prokaryote and eukaryote. One difference is

Answer 58

THE FORMATION OF POLYSOMES

Question 59

An equipment used in PCR that is programmed to shift the levels of temperature giving way to the three stages of PCR cycles:

Answer 59

THERMAL CYCLER

Question 60

What name is given to any (organic or inorganic) nonprotein portion of an enzyme?

Answer 60

COFACTOR

Question 61

What cannot be oxidized by Benedict’s and Fehling’s reagents?

Answer 61

SUCROSE

Question 62

Which of the following is true of enzymes?

Answer 62

They increase the rate of reaction by stabilizing the transition state

Question 63

They are sugars in which the terminal carbon’s hydroxyl group has been oxidized to a carboxylic acid

Answer 63

URONIC ACID

Question 64

The eukaryote small ribosomal subunit is

Answer 64

40S

Question 65

A PCR reaction that continues for 30 cycles will produce approximately how many PCR products from a single template DNA molecule?

Answer 65

APPROXIMATELY 1 BILLION

Question 66

Temperature level required for elongation step of PCR: Choose the closest range.

Answer 66

70-75° C

Question 67

For each generation of each cell, how many rounds of replication occur?

Answer 67

ONE

Question 68

At least how many cycles of PCR are needed to produce an adequate amount of DNA strands?

Answer 68

30

Question 69

It is a polysaccharide in which only one type of monosaccharide monomer is present

Answer 69

HOMOPOLYSACCHARIDE

Question 70

What structural feature distinguishes an aldose and a ketose?

Answer 70

AN ALDOSE POSSESS AN ALDEHYDE GROUP, AND A KETOSE POSSESS A KETONE GROUP

Question 71

The initiating codon in for most translation processes is

Answer 71

AUG

Question 72

What compounds is a COMPETITIVE INHIBITOR to dihydrofolate reductase?

Answer 72

METHOTREXATE

Question 73

Carbohydrates is made up of different components such as

Answer 73

CARBON, HYDROGEN AND OXYGEN

Question 74

What is the effect of UVL in the DNA?

Answer 74

IT WILL CAUSE PYRIMIDINE DIMER FUNCTION

Question 75

At the initiation stage of protein synthesis, fmet-tRNA binds to this site of the big ribosomal subunit

Answer 75

P

Question 76

In prokaryotes, the small ribosomal subunit uses this as a guide to find the first codon to be translated

Answer 76

SHINE DALGARNO SEQUENCE

Question 77

What is meant when it is said that carbohydrates are optically active compounds?

Answer 77

A SOLUTION OF CARBOHYDRATE WILL ROTATE THE PLANE OF POLARIZED LIGHT

Question 78

S-Adenosyl methionine (SAM) is a molecule utilized in various metabolic pathways to transfer methyl groups from SAM to an acceptor. What is the proper designation of the complex of SAM and its enzyme together?

Answer 78

HOLOENZYME

Question 79

The big subunit of the prokaryotic ribosome is

Answer 79

50S

Question 80

In sequential order, what are the three steps of PCR?

Answer 80

DENATURE DNA, ANNEAL PRIMERS, EXTEND PRIMER/ DNA

Question 81

The transition state of a catalyzed reaction is

Answer 81

LOWER IN ENERGY THAN THAT OF AN UNCATALYZED REACTION

Question 82

What sugar rotates at +66.5°?

Answer 82

SUCROSE

Question 83

The following terminate protein synthesis EXCEPT

Answer 83

UUA

Question 84

Prior to a marathon run, an athlete consumes a large amount of complex carbohydrates to do what is known as “carbohydrate loading”. What happens in the body to the glucose molecules present in these complex carbohydrates? (additional 30s)

Answer 84

The complex carbohydrates are broken down to glucose and any excess glucose, not used for immediate energy, is stored in the form of glycogen, which can be used later as a source of stored energy.