BIO 205

Question 1

Describe the role of mRNA in protein synthesis.

Answer 1

mRNA is translated into a polypeptide sequence, serving as a template for protein synthesis.

Question 2

Define the central dogma of molecular biology.

Answer 2

The central dogma describes the flow of genetic information from DNA to RNA to proteins.

Question 3

Describe the difference between transcription and translation.

Answer 3

Transcription is the process of converting DNA to RNA while translation is the process of converting RNA to proteins.

Question 4

What is the structure of DNA composed of?

Answer 4

nucleotides

Question 5

Describe the components of a nucleotide.

Answer 5

A nucleotide consists of a pentose sugar, a phosphate group, and a purine or pyrimidine.

Question 6

How do the structures of purines and pyrimidines differ?

Answer 6

Purines have a larger structure because they are double ringed, while pyrimidines are single ringed and therefore smaller.

Question 7

what is the significance of the 5’ and 3’ ends of DNA?

Answer 7

DNA runs (is read) from 3’ to 5’ with the phosphates being attached to the 5’ carbon and a hydroxyl group attached to the 3’ carbon.

Question 8

What is the function of ribosomes?

Answer 8

They are responsible for translating mRNA into proteins.

Question 9

How does the primer work in correlation to the orientation of DNA.

Answer 9

The primer runs antiparallel to the DNA strand during replication.

Question 10

Describe the order of processes in the central dogma of biology.

Answer 10

The order of the processes of the central dogma are DNA replication, transcription, and translation.

Question 11

Describe the role of phosphodiester bonds in DNA structure.

Answer 11

Phosphodiester bonds are strong covalent bonds that join nucleotides together, forming the backbone of DNA through a condensation reaction.

Question 12

How does the 3’ hydroxyl group interact with the 5’ phosphate group in DNA?

Answer 12

The 3’ hydroxyl group of one nucleotide is bonded to the 5’ phosphate of another, linking them together. This force is called Van Der Wall’s force.

Question 13

Explain the charge of DNA and how this relates to its directionality and movement in a gel electrophoresis experiment.

Answer 13

DNA is negatively charged due to all of the phosphates. Therefore, DNA will move towards the positive end of a gel dish.

Question 14

Define the hydrophilic and hydrophobic properties of DNA components.

Answer 14

The phosphate backbone of DNA is hydrophilic, attracting water, while the bases in the middle are hydrophobic, repelling water.

Question 15

How are complimentary base pairs arranged in DNA?

Answer 15

Adenine double bonds to thymine, and guanine triple bonds to cytosine. Thus, A=T and C=G.

Question 16

What is a chromosome?

Answer 16

A unit or molecule that contains genetic information.

Question 17

Define a genome.

Answer 17

A genome is the complete set of genetic information found in an organism, necessary for its functioning.

Question 18

Describe the bonding force when DNA stacks.

Answer 18

The stacking force in DNA is known as Van Der Wal’s force, it is a weak covalent bond that occurs between nucleotides that are stacked one above the other in the double helix orientation of DNA.

Question 19

How does GC content affect the melting point of DNA?

Answer 19

GC, Guanine and Cytosine, are triple bonded, therefore it takes more energy to break them. DNA with a higher concentration of CG, compared to AT, will need more energy to break, meaning the melting point will be higher.

Question 20

Where is genomic information located in a prokaryotic cell?

Answer 20

Genomic DNA is located in the nucleoid region, while plasmid DNA is located in the extrachromosomal region.

Question 21

What is one function of plasmids?

Answer 21

Plasmids contain non-necessary DNA but are responsible for antibiotic resistance.

Question 22

What is unique about plasmid replication?

Answer 22

Plasmids are self replicating which means that they can do it on their own.

Question 23

How does DNA fit in small spaces within the cell?

Answer 23

DNA coils and then there are proteins that supercoil it to fit in a smaller space.

Question 24

What is the function of histones in eukaryotic cells?

Answer 24

Histones are proteins that have strands of DNA wrapped around them for packaging.

Question 25

Define Chromatin.

Answer 25

The combination of histone proteins and coiled DNA in a strand is called chromatin.

Question 26

Define nucleosome.

Answer 26

A nucleosome is a single unit of a protein wrapped in DNA.