Molecular Biology

Front 1

What is the purpose of DNA replication?

Back 1

To ensure the daughter and parent cell have a complete set of genetic information

Front 2

What is the purpose of transcription?

Back 2

To produce a "copy" of DNA in the form of mRNA.

Front 3

What is the purpose of translation?

Back 3

To translate the genetic info carried from the nucleus in the form of mRNA into a chain of amino acids, which will form a polypeptide (which will then fold into a protein).

Front 4

What is the role of DNA helicase in DNA replication?

Back 4

DNA helicase unwinds the parent strand by breaking apart the hydrogen bonds which hold the bases of the 2 strands together.

Front 5

What is the role of DNA polymerase in DNA replication? (2 roles)

Back 5

(i) forms the sugar-phosphate backbone (catalyzes the rxn). (ii) joins new complementary nucleotides to the exposed bases of the parent strand.

Front 6

What is the role of DNA ligase?

Back 6

It ensures bonding between fragments and replaced nucleotides. Also catalyzes the rxn between sugar and phosphate on the lagging strand.

Front 7

What is the role of single stranded binding proteins?

Back 7

Prevents DNA sequences from joining together again after being unwound.

Front 8

What is the role of nucleotides in DNA replication?

Back 8

Are picked up (out of the nucleoplasm) by DNA polymerase; makes new DNA.

Front 9

What is the role of parent strands in DNA replication?

Back 9

Need to be broken apart to form daughter strands with identical DNA.

Front 10

Define replication

Back 10

Making an exact copy of DNA

Front 11

Define template

Back 11

Pattern/model that serves as a mold for the production of a complementary shaped structure.

Front 12

Define antiparralel

Back 12

Facing in opposite directions

Front 13

Define recombinant DNA

Back 13

DNA from 2 different sources joined (spliced) together

Front 14

Define plasmid

Back 14

A small ring of DNA that carries additional genes.

Front 15

Define restriction endonuclease

Back 15

enzymes which cut DNA at specific locations and creates unpaired nitrogenous bases (sticky ends)

Front 16

Define gene splicing

Back 16

The joining together of DNA segments using enzymes

Front 17

Define DNA ligase

Back 17

An enzyme which splices sections of DNA together by forming covalent bonds between sugar and phosphate groups

Front 18

Define transformation

Back 18

the uptake of similiar DNA present in the environment by a bacteria cell

Front 19

Define code

Back 19

each 3 unit base/nucleotide of DNA

Front 20

Define anticodon

Back 20

3 exposed nucleotides which can complementary base pair with 3 mRNA nucleotides

Front 21

Define codon

Back 21

3 base/nucleotide unit of mRNA

Front 22

Where does transcription occur?

Back 22

Nucleus of eukaryotic cells

Front 23

Where does translation occur?

Back 23

Ribosomes

Front 24

Translation vs Transcription?

Back 24

Trancription produces a "copy" of DNA in the form of mRNA

Translation turns mRNA into an amino acid chain (polypeptide)

Front 25

Germinal vs Somatic Mutations

Back 25

Germinal mutations are a change of DNA in germ cells (gametes) and can be passed on to offspring

Somatic mutations are a change of DNA in a body cell that are not inheritable, and only affects the individual who get it (i.e. cancer)

Front 26

Describe recombinant DNA producing human proteins

Back 26

Since bacteria has human genes located in the DNA plasmid, a small amount of protein is produced. Binary fission occurs which replicates the cell in large amounts so large amounts of protein are produced.

Front 27

define mutagen

Back 27

an environmental factor which causes mutations

Front 28

define mutation

Back 28

a change

Front 29

define gene mutation

Back 29

a change in the sequence of the nitrogenous bases in a DNA molecule

Front 30

define point mutation

Back 30

a change in the DNA at a single nucleotide pair

Front 31

Example of chemical mutation?

Back 31

asbetos, carcigens, food additives etc

Front 32

Example of raditation mutations

Back 32

uv rays, gamma rays

Front 33

identify the role of DNA in protein synthesis and the stage it happens in

Back 33

stage: transcription

role: determines the amino acid sequence in a protein and contains the genetic code

Front 34

identify the role of tRNA in protein synthesis and the stage it occurs in

Back 34

stage: translation

role: carries specific amino acids to the ribosomes for assembly into proteins

Front 35

identify the role of mRNA in protein synthesis and the stage it occurs in

Back 35

stage: translation

role: moves through the nuclear pores to cytoplasm; carries the genetic info to the ribosomes so the 2nd stage of protein synthesis can occur

Front 36

identify the role of ribosomes in protein synthesis and the stage it occurs in

Back 36

stage: translation

role: makes protein (site of translation)

Front 37

identify the role of RNA polymerase in protein synthesis and the stage it occurs in

Back 37

stage: transcription

role: moves along the DNA strand and breaks the hydrogen bonds between DNA

Front 38

identify the role of the promoter site in protein synthesis and the stage it occurs in

Back 38

stage: this is where transcription occurs

role: binding site for RNA polymerase enzyme

Front 39

identify the role of the release factor in protein synthesis and the stage it occurs in

Back 39

stage: translation

role: binds to the A site in ribosomal complex

Front 40

identify the role of the termination codon in protein synthesis and the stage it occurs in

Back 40

stage: translation

role: seizes elongation and causes the entire ribosome assembly complex to break apart and stops any further translation

Front 41

identify the role of amino acids in protein synthesis and the stage it occurs in

Back 41

stage: end of translation

role: forms polypeptide chain and therefore the protein (primary protein sequence).

Front 42

What is a insertion mutation?

Back 42

One extra nucleotide added to a DNA sequence

Front 43

What is a deletion mutation?

Back 43

Removing one nucleotide from a DNA sequence

Front 44

What is a substitution mutation?

Back 44

Replacing 1 nucleotide and its partner with another nucleotide pair.

Front 45

What is a silent mutation?

Back 45

When a substitution mutation has no effect on the cell.

Front 46

Why is a DNA molecule described as antiparralel and why is this significant?

Back 46

It's described as antiparralel because the bases in DNA pair in such a way that the sugar phosphate groups are oriented in different directions. This is significant because different orientations results in different replications; the leading strand can be synthesized continuously while the lagging strand can be synthesized in short fragments.