Topic Four Flashcards
Nucleotide sturcture
They are composed of a nitrogen base and a five carbon sugar with a phosphate
What determines the nucleotide type
The type of nitrogen base
Where is the nitrogen attached to the nucleotide structure
It is attached to the parent carbon #1
Where do the phosphates connect on the nucleotide structure
They attached the carbon number 5
Amount of bond that are formed between A and T sturctures
They form two hydrogen bonds
Amount of bonds that are formed by C and G nucleotides
They form three hydrogen bonds
What are the two types of nitrogenous bases
Purines and pyrimidines
What is a purines? Which nucleotides do they include
They are double ringed and they contain A and G
What is a pyrimidines? Which nucleotide do they include
They are single ringed and they include C,U, and T
What is the different between the sugars of DNA and RNA
RNA has an extra oxygen in position 2 around the ring
Which nucleotides bond with each other in DNA
G to C and A to T
Which nucleotides bond together in RNA
G to C and A to U
What is the structure of DNA
- has a sugar and phosphate backbone (alternates between sugar and phosphate)
- is double stranded and is connected through hydrogen bonds between bases
- strands are anti-parallel (not the exact same because of complementary base pairing
Which end of the DNA is considered the 5’ end
The strand on the backbone that has the phosphate group first
Which end of the DNA is considered to be the 3’ end
The end on the backbone where the sugar is exposed with the OH group facing out ward
What are the Three methods of genetic information flow
-expression
- recombination
- replication
What is replication in terms of genetic flow
This occurs when the genetic material is multiplied to create a two daughter cells ;genetic information can be transferred between generations of cells
- one chain of genetic information is provided from the parents and one strand is tue new chain (semi conservative)
In what species is DNA replication most common
Is most common in bacterial cells
What is the process of DNA replication
Which method of genetic flow is most accurate
Replication because of its caviling of proofreading by the DNA polymerases
I’m the process of replication what is toooisomerase
It relieves tension ahead of the replication forks
In the process of replication what is helicase
It unwinds and unzips the DNA
In DNA replication what is the leading strand
The DNA strand that is made from 5’ to 3’
In DNA replication what is the lagging strand
A strand that grows in the 3’ to 5’ end
What is gene expression in terms of the flow of genetic information
The process by which DNA directs protein synthesis
- uses two stages: transcription and translation
- uses information in the genes to program a new proteins
What is the process of transcription
- RNA polymerase to bind to the promoter region and DNA unwinds
- the RNA polymerase the uses the template DNA strand to code a strand of RNA
- the RNA polymerase then reached the stop codon where the polymerase and the RNA strand are both released and the helix is the reconnected
What is the process of translation
- the RNA strand is the he translated into an amino acid sequence using 3 codons at a time this process starts at the start codon (AUG)
What is redundancy
Where there are different ways to code for the same amino acid
When you are asked to code something from DNA how do you do that
- start by taking the first DNA strand and code the template strand
- take that template strand and code the mRNA strand
- then code the other side of the mRNA strand which are then the codons for the proteins (this second strand of the mRNA are the tRNA)
Where does translation occur
Happens inside the ribosomes
What is a polyribosome
When an organism Splenda up the process of protein synthesis but compiling multiple ribosomes in a chain
What is the different between prokaryotic and Eukaryotic gene expression
-In prokaryotes transcription and translation both happen in the cytoplasm
- in eukaryotes transcription happens in the nucleus and the translations happens outside of the nucleus inside the ribosomes (when the mRNA strand leaves the the nucleus, ends are added to the 3’ and 5’ to protect the coded strand)
What is genetic combination
When DNA is combined when a cell takes in the genetic material
What is vertical gene transfer
Occurs during reproduction between generations of cells
What is horizontal/lateral gene transfer
The transfer of genes between cells of the same generation
What are the results of horizontal gene transfer
- leads to genetic recombination
- can contribute to antibiotic resistance
What are the three ways of horizontal gene transfer
-conjugation
- transformation
- transduction
What is conjugation horizontal gene transfer
It is the fdirect transfer of DNA from one bacterium to another (when one strand of DNA is but into a different bacteria)
What is transformation horizontal gene transfer
When the bacterium take up free DNA outside the cell
What is transduction horizontal gene transfer
When a bacterial virus takes DNA from one bacterial to another (when the DNA is directly inserted into the other cell)
What is a mutation
A change in genetic material of a cell
What are the two main groups of mutations
- point mutations
- frameshift
What is a point mutation
When one base pair of a gene is replaced by something different that impacts the amino acid outcome
What are the three types of point mutations? And what happens at each.
- silent: when a base pair is changed but the amino acid is still the same
- missense: when a base pair is changed and a different amino acid is coded
- nonsense: when a base pair is changed and a stop codon is coded and not an amino acid
What is a frameshift mutation
When the mRNA is read incorrectly and results in a non functional protein
- this type of mutations is a lot more servre
- this type of mutations are commonly cause by insertions or deletions
