Fuels and Biofuels: Cellular Biosystems; Genes, DNA and Proteins

Question 1

What is genomics?

Answer 1

The study of all the genes of an organism

Question 2

What is DNA?

Answer 2

It is a polymer that is made of monomer nucleotides

Question 3

What is a nucleotide made of?

Answer 3

A nitrogenous base, a deoxyribose sugar and a phosphate group

Question 4

How are the nucleotides joined together to form DNA?

Answer 4

deoxyribose sugar of the nucleotides are covalently bonded to the phosphate of the next nucleotide (creates a sugar-phosphate backbone)

Question 5

What are the 4 nitrogenous bases? What are the structures of each?

Answer 5

Thymine and cytosine = single ring

adenine and guanine = double ring

Question 6

How are the bases held together? What kind of pairing do they do?

Answer 6

By hydrogen bonds, A T, G C

Question 7

What is the rule that describes the number of nitrogenous bases in DNA? Explain the rule

Answer 7

Chargaff’s rule describes that there are always equal number of A and T, G and C

Question 8

What is the type of bonding between A and T, G and C known as?

Answer 8

Complementary binding

Question 9

What is the structure of DNA?

Answer 9

A double helix

Question 10

How does DNA replicate?

Answer 10

DNA polymerase (it’s an enzyme) separates the helix and joins complementary bases to each strand then stitches it back together creating a daughter and parental strand

Question 11

What are the two strands produced in DNA replication called? Why are they called this?

Answer 11

• Leading strand and lagging strand

- Leading = continuously produced, lagging = done in section (as it is being done backwards relative to leading)

Question 12

What is a gene?

Answer 12

A section of DNA coding for a specific protein

Question 13

What is the entire DNA in a nucleus of an organism called?

Answer 13

Genome

Question 14

What is a genotype?

Answer 14

The particle sequence of nucleotides bases in an organism

Question 15

What is a phenotype?

Answer 15

The organisms particular characteristics that are controlled by proteins

Question 16

Where are proteins produced in a cell?

Answer 16

On the ribosomes out in the cytoplasm of the cell

Question 17

How does DNA transfer its genetic information to the ribosomes?

Answer 17

Creates mRNA which contains a copy of the genetic information and transfers it to the ribosomes

Question 18

What is the process of creating mRNA called?

Answer 18

Transcription

Question 19

What is the process of turning the genetic information of the mRNA into proteins?

Answer 19

Translation

Question 20

What is RNA?

Answer 20

It is another type of nucleic acid

Question 21

What is the difference between RNA and DNA?

Answer 21

RNA is single stranded, has a ribose sugar instead of deoxyribose, the nitrogenous base uracil instead of thymine and has sever forms (e.g. messenger, transfer and ribosomal RNA)

Question 22

How does the mRNA leave the nucleus?

Answer 22

Through nuclear pore

Question 23

What is the function of nuclear pores?

Answer 23

control the flow of genetic information leaving the cell

Question 24

How are mRNA bases read during translation?

Answer 24

In groups of three bases called codons

Question 25

How many amino acids are there? How many combinations of codons are there? What does this imply?

Answer 25

• 20 amino acids + stop codon (not an actual amino acid)
• 64
• Redundancy (multiple different codons for same genetic information)

Question 26

DNA is made up of sections of genetic information that isn’t used directly in the production of proteins, what are the different coding and non-coding regions called?

Answer 26

Introns = non-coding
Exons = coding

Question 27

What happen to the introns and axons during transcription?

Answer 27

Everything is copied to the mRNA but the introns are removed and the axons are spliced together

Question 28

How is the mRNA read and turned into a protein?

Answer 28

anti-codons (which is a special type of trinucleotide FYI) are complementary to one or more mRNA codons that specific the amino acid being carried by the tRNA (anti-codons are on the tRNA FYI)

Question 29

What is the difference in reading order between a codon and anti-codon?

Answer 29

Codons read from 5’ –> 3’ while anti-codons read for 3’ –> 5’

Question 30

What are the four levels of protein structure?

Answer 30

Primary, secondary, tertiary, quaternary

Question 31

What changes between the different levels of protein structure?

Answer 31

Increasing complexity of the shapes

Question 32

Describe each level of protein structure

Answer 32

• Primary = polypeptide chain
• Secondary = folding of primary structure as either alpha helix or beta pleated sheets
• tertiary = 3D shape made of multiple secondary structures
• Quaternary = bonding of multiple tertiary structures

Question 33

What are the different types of mutations possible?

Answer 33

Base substitutions, Bases insertions and Base deletions

Question 34

Explain each type of mutation and describe the impacts on the expression of the protein and why

Answer 34

• Base substitution = where a nucleotide/base is is swapped for another, range for no (redundancy) to major (change of amino acid) affects
• Base deletion = where a nucleotide is removed from the DNA, causes frame shift which is likely to have major impact
• Base insertin = where a nucleotide is added from DNA, same impact as deletion