The DNA
-Deoxyribonucleic Acid
-is a polymer of nucleotides
-Discovered by Watson and Crick
Four kinds of nitrogenous bases
•Purine bases(Adenine,guanine)
•Pyrimidine bases(Cytosine,thymine)
DNA replication
occurs before a cell divides, ensuring that the cells in a multicellular organism all carry the same genetic information.It is also the mechanism for producing the DNA copies that offspring inherit from parents during reproduction.
RNA
RIBONUCLEIC ACID
-A pairs with U; G pairs with C
-single stranded and shorter
Genetic Code
-consists of 64 codons,
-but only 61 code amino acids.
-Three codons act as a signal to stop the process.
-One codon, AUG, codes for methionine, and is also the Start signal for translation.
Mutations
Changes in the DNA sequence, that may be passed along to future generations.
Point mutations
A Single base substitution.
-THE CAT SAW THE RAT
-THE CAT SAW THE HAT
Deletion
a small DNA segment is lost.
Insertion
a segment of DNA is added.
Frame-shift mutation
Modification of the reading frame after a deletion or insertion, resulting in all codons downstreams being different.
Messenger RNA (mRNA)
Is a type of molecule of RNA that travels from the nucleus to the ribosomes, where the information in the copy is used for a protein product
Ribosomal RNA (rRNA)
Is the RNA component of the ribosome and a cell’s protein factory in all living cells. It provides a mechanism for decoding mRNA into amino acid and interacts with tRNA
Transfer RNA (tRNA)
-Is an adaptor molecule composed of RNA, typically 73 to 93 nucleotides in length that brings amino acids from the cytoplasm to a ribosome to help the make the growing protein .
-Transport molecule that carry specific amino acid to a ribosome.
-Each tRNA recognizes the correct codon,on the mRNA molecule.
Genetic code
Is shared by all organisms.
Codon CAU
It can be fined by the amino acid histidine as encoded by
Prokaryote or a eukaryote
The copy of the DNA happens where the cell is either
DNA polymerase**.**
Is responsible in bonding the new nucleotide together.
Enzymes and other proteins
Are responsible for the process of replication
Enzyme
Begins the process by unzipping the double helix to separate the strands of DNA
Floating free nucleotides
Will be paired with the nucleotide of the existing DNA strand
DNA
Is found inside the nucleus of the cells which are embedded in the chromosomes.
The transcription process
Occurs when the nucleotide sequence along the DNA is copied into a strand of mRNA
DNA Strand
Will be exposed once the DNA molecule uncoils
RNA polymerase
Is responsible for the alignment and binding together of the ribonucleotides that will create the single strand of RNA molecule
Translation
Is the final step in the synthesis of a small protein through the help of the mRNA.
Nucleic acid
Large molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Nucleic acid
Large molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Double helix
DNa has two strands of nucleotides joined together to form a twisted molecule which looks like a ______