Fuels and Biofuels: Cellular Biosystems; Genes, DNA and Proteins Flashcards
What is genomics?
The study of all the genes of an organism
What is DNA?
It is a polymer that is made of monomer nucleotides
What is a nucleotide made of?
A nitrogenous base, a deoxyribose sugar and a phosphate group
How are the nucleotides joined together to form DNA?
deoxyribose sugar of the nucleotides are covalently bonded to the phosphate of the next nucleotide (creates a sugar-phosphate backbone)
What are the 4 nitrogenous bases? What are the structures of each?
Thymine and cytosine = single ring
adenine and guanine = double ring
How are the bases held together? What kind of pairing do they do?
By hydrogen bonds, A T, G C
What is the rule that describes the number of nitrogenous bases in DNA? Explain the rule
Chargaff’s rule describes that there are always equal number of A and T, G and C
What is the type of bonding between A and T, G and C known as?
Complementary binding
What is the structure of DNA?
A double helix
How does DNA replicate?
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
What are the two strands produced in DNA replication called? Why are they called this?
- Leading strand and lagging strand
- Leading = continuously produced, lagging = done in section (as it is being done backwards relative to leading)
What is a gene?
A section of DNA coding for a specific protein
What is the entire DNA in a nucleus of an organism called?
Genome
What is a genotype?
The particle sequence of nucleotides bases in an organism
What is a phenotype?
The organisms particular characteristics that are controlled by proteins
Where are proteins produced in a cell?
On the ribosomes out in the cytoplasm of the cell
How does DNA transfer its genetic information to the ribosomes?
Creates mRNA which contains a copy of the genetic information and transfers it to the ribosomes
What is the process of creating mRNA called?
Transcription
What is the process of turning the genetic information of the mRNA into proteins?
Translation
What is RNA?
It is another type of nucleic acid
What is the difference between RNA and DNA?
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)
How does the mRNA leave the nucleus?
Through nuclear pore
What is the function of nuclear pores?
control the flow of genetic information leaving the cell
How are mRNA bases read during translation?
In groups of three bases called codons
How many amino acids are there? How many combinations of codons are there? What does this imply?
- 20 amino acids + stop codon (not an actual amino acid)
- 64
- Redundancy (multiple different codons for same genetic information)
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?
Introns = non-coding Exons = coding
What happen to the introns and axons during transcription?
Everything is copied to the mRNA but the introns are removed and the axons are spliced together
How is the mRNA read and turned into a protein?
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)
What is the difference in reading order between a codon and anti-codon?
Codons read from 5’ –> 3’ while anti-codons read for 3’ –> 5’
What are the four levels of protein structure?
Primary, secondary, tertiary, quaternary
What changes between the different levels of protein structure?
Increasing complexity of the shapes
Describe each level of protein structure
- 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
What are the different types of mutations possible?
Base substitutions, Bases insertions and Base deletions
Explain each type of mutation and describe the impacts on the expression of the protein and why
- 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
