Storing and Using Genetic Information

Question 1

What is a phenotype

Answer 1

A outward, physical manifestation of organism

Question 2

What is a genotype

Answer 2

The full hereditary information of organism (even if not expressed)

Question 3

Why are proteins all functionally different

Answer 3

Due to their structure

Question 4

What is protein structure dependent on

Answer 4

The primary structure and therefore the specific sequence of amino acids

Question 5

What is the molecular structure of DNA

Answer 5

It is a chain of nucleotide monomers

Question 6

What does each nucleotide contain

Answer 6

Sugar
Base
Phosphate group

Question 7

What is the sugar on DNA called

Answer 7

2’ - deoxyribose

Question 8

What shape do DNA molecules form

Answer 8

Double helix

Question 9

What is the backbone of DNA

Answer 9

Sugar phosphate

Question 10

How many bases are there for every full turn of the helix in DNA

Answer 10

10

Question 11

Do the polynucleotide chains run parallel or anti-parallel to each other

Answer 11

Anti-parallel

One runs 5’ to 3’ while the other runs 3’ to 5’

Question 12

How does the polynucleotide chains running anti-parallel to each other affect the double helix

Answer 12

It allows it to remain stable

Question 13

What does the way the double helix is wound result in

Answer 13

Major groove

Minor groove

Question 14

In which groove are many binding sites found

Answer 14

Major

Question 15

Why are the grooves formed important in DNA

Answer 15

For the interaction of proteins with the DNA molecule

Question 16

Is the double helix, right or left handed

Answer 16

Right handed

Question 17

What are the bases in DNA

Answer 17

Adenine
Cytosine
Guanine
Thymine

Question 18

How to the bases pair in DNA

Answer 18

A-T

C-G

Question 19

Which base is switched in RNA

Answer 19

Thymine becomes Uracil

Question 20

How many bonds are found between A-T

Answer 20

2 hydrogen bonds

Question 21

How many bonds are found between C-G

Answer 21

3 hydrogen bonds

Question 22

Describe the nucleus

Answer 22

The largest organelle in the cell
Contains most of the cell’s genetic material (DNA)
Replication of DNA and the first steps in decoding it for protein production take place in the nucleus

Question 23

How big is the nucleus

Answer 23

5-10 μm in diameter

Question 24

When are chromosomes visible in a cell

Answer 24

Only when the cell is dividing

Question 25

What is DNA packaged into in the nucleus

Answer 25

Thread-like structures called chromosomes

Question 26

What are chromosomes

Answer 26

A single piece of DNA containing many genes, regulatory elements and other nucleotide sequences

Question 27

How many chromosomes do humans have

Answer 27

46

Question 28

What is chromatin

Answer 28

The mixture of DNA, proteins and RNA that package DNA within the nucleus

Question 29

Which two forms of chromatin can be found

Answer 29

Heterochromatin (condensed) | Euchromatin (extended)

Question 30

What do transcription and replication require

Answer 30

The two strands of DNA to separate temporarily to allow enzymes access to the DNA template

Question 31

What are barriers to enzymes in transcription and replication

Answer 31

Nucleosomes and folding of chromatin

Question 32

Name two major reversible mechanisms by which chromatin is made more accessible

Answer 32

Histones can be enzymatically modified | Histones can be displaced by chromatin remodeling complexes

Question 33

What does it mean when it is said that DNA replication is semi-conservative

Answer 33

One-half of each new molecule of DNA is old; one-half new

Question 34

What must be broken to split the double helix

Answer 34

Hydrogen bonds

Question 35

In what direction is DNA replicated

Answer 35

5' to 3'

Question 36

Where can DNA polymerase add new nucleotides

Answer 36

Only to the 3' end of the growing strand

Question 37

What are formed on the lagging strand

Answer 37

Okazaki fragments

Question 38

How are okazaki fragments joined to produce one continuous strand

Answer 38

By DNA ligase

Question 39

How is the 5' end of the lagging strand replicated

Answer 39

A specialized enzyme, telomerase, replicates the 5’ ends of the lagging strand

Question 40

How many bases are exactly the same in all people

Answer 40

99.9%

Question 41

What are exons

Answer 41

Coding regions

Question 42

What are introns

Answer 42

Non-coding regions

Question 43

What happens to introns and exons in transcription

Answer 43

Introns - eliminated | Exons - spliced

Question 44

What does the genetic code describe

Answer 44

How base sequences are converted into amino acids

Question 45

What is a set of three bases called

Answer 45

Codon

Question 46

What does each codon specify

Answer 46

A particular amino acid

Question 47

How many codons can be formed from 4 bases

Answer 47

4^4 = 64 codons

Question 48

How many amino acids have been found in proteins

Answer 48

20

Question 49

Which amino acids are only coded for by one codon

Answer 49

Methionine | Tryptophan

Question 50

What is methionine also termed

Answer 50

Initiation codon as this is the signal for protein synthesis to begin

Question 51

What is degeneracy

Answer 51

The number of codons is greater than the number of amino acids

Question 52

What can single point mutations cause

Answer 52

Dysfunctional proteins

Question 53

Give an example of a single point mutation producing a dysfunctional protein

Answer 53

Mutated haemoglobin gene causes Sickle Cell Anaemia In the mutant hemoglobin a hydrophilic glutamate (Glu) is substituted by the hydrophobic valine (Val), (GAA or GAG becomes GUA or GUG)

Question 54

What is the major role of RNA

Answer 54

To participate in protein synthesis

Question 55

What types of RNA are there

Answer 55

``` Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA) ```

Question 56

What is mRNA

Answer 56

It is transcribed from DNA and carries information for protein synthesis

Question 57

What is alternative splicing

Answer 57

A process by which the exons of the RNA produced by transcription of a gene (a primary gene transcript or pre-mRNA) are reconnected in multiple ways during RNA splicing

Question 58

What does alternative splicing result in

Answer 58

The resulting different mRNAs may be translated into different protein isoforms; thus, a single gene may code for multiple proteins

Question 59

What does alternative splicing increase

Answer 59

Diversity of proteins that can be encoded by the genome

Question 60

What does the initiation codon determine

Answer 60

The reading frame of the RNA sequence.

Question 61

What is a open reading frame

Answer 61

A set of codons runs continuously and is bounded by a start/initiation codon and a termination codon

Question 62

What does the open reading frame identify

Answer 62

DNA which encodes protein sequences in genome sequencing projects

Question 63

What occurs in the nucleus

Answer 63

Transcription (DNA to mRNA) and alternative splicing

Question 64

What occurs in the cytoplasm

Answer 64

Post translational modifications | tRNA, rRNA and protein present here

Question 65

What is the major role of tRNA

Answer 65

To translate mRNA sequence into amino acid sequence  | Acts as an adapter molecule between the coded amino acid and the mRNA

Question 66

What is rRNA

Answer 66

A component of ribosomes

Question 67

Where are rRNA molecules produced

Answer 67

In the nucleus | Transported to cytoplasm, where they combine with proteins to form a ribosome

Question 68

What is a polysome

Answer 68

Several ribosomes can translating mRNA at one time