Genome Flashcards
What is a genome?
An organism’s complete set of DNA is called its genome. Needs to be managed to allow information to be: Used by the cell to express proteins in a controlled way. Replication accurately to be passed on to next generation.
There are 3000000000 base pairs and 23000 protein coding genes.
What is transcription?
Transcription, the synthesis of RNA from DNA. Genetic information flows from DNA into protein, the substance that gives an organism its form. This flow of information occurs through the sequential processes of transcription (DNA to RNA) and translation (RNA to protein). Transcription occurs when there is a need for a particular gene product at a specific time or in a specific tissue.
What is translation
Translation refers to the process of creating proteins from an mRNA template. The sequence of nucleotides on the RNA is translated into the amino acid sequence of proteins and this reaction is carried out by ribosomes. Ribosomes and tRNA dock on a mature mRNA transcript and recruit multiple enzymes in an energy intensive process that uses ATP as well as GTP.
What is a karyotype?
A karyotype is simply a picture of a person’s chromosomes. In order to get this picture, the chromosomes are isolated, stained, and examined under the microscope.
What is a haploid genome?
When you have one copy of every chromosome.
Describe the structure of Chromatin?
Chromatin is located in the nucleus of our cells. The primary function of chromatin is to compress the DNA into a compact unit that will be less voluminous and can fit within the nucleus. Chromatin consists of complexes of small proteins known as histones and DNA
What is heterochromatin?
Highly codensed chromatin, generally gene poor, transcriptionally inactive.
What is a Euchromatin?
Prevaent in gene-rich areas, less compact allowing access for proteins involved in transcription.
In what phases of cell division can you see Chromatins?
Interphase:Cannot see chromatins
During mitosis you can see the condenced chromatins.
Image of Nuleotides joined by phosphodiester linkage.
We describe our sequence from the 5 point end of the chain to the 3 point end of the chain.
Describe the process of semi-conservative replication?
The enzyme DNA helicase breaks the hydrogen bonds between the two polynucloetide DNA strands causing the double helix to unzip, forming two single strands.
Each original single strand then acts as a template for a new strand. Free-floating DNA nucloetides join to the exposed bases on each original template strand via complementary base pairing.
The nucloetides of the new strands are joined together by the enzyme DNA polymerase. This forms the sugar-phosphate backbone. Hydrogen bonds form between the bases on the original and new strand and the strands twist to reform the double helix.
Each new DNA molecule contains one strand from the original DNA molecule and one new strand, hence the term semi-conservative replication.
What directon does DNA polymerase work?
From 5 point to 3 point end of chain.
What is a replication orgin?
The site where DNA is initially ripped apart and replicated.
What are okazaki fragments?
Okazaki fragments are short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication