DNA And RNA Flashcards
DNA
location
How may strands
Deoxribonucleic acid
Located inside the nucleus
Two strands
DNA also found
Mitochondria and chloroplasts
4 bases
Adenine
Thymine
Guanine
Cystosine
Bonds of bases
A—>T
G—>C
What shape DNA
Double helix
Gene
Gene is a section of DNA that causes the production of protein
Codon
Sequence of three bases
Non coding DNA
They do not have a code for the formation of a protein
DNA replication
When mitosis occurs one cell divides into two identical daughter cells
Occurs so there is a direct copy of the DNA for mitosis to occur
Occurs during interphase
How does DNA replication occur
Double helix unwinds
Enzymes break bonds between base pairs
Other DNA bases enter the nucleus and join with the exposed DNA strand
Each new strand is identical to the original strand
DNA profiling
A method of making a unique pattern of bands from the DNA of a person which is then used to tell the difference of that DNA from another DNA
Method of DNA profile
DNA is released
DNA is cut into fragments
Fragments are depressed
Patterns are compared
DNA is released
DNA is released by the breaking down if the cell
DNA is cut into fragments
Is listed DNA is cut into fragments using enzymes (restriction enzymes) depending on the sequence of bases
Fragments are superstars
Separated based on their size
Separated by a process called gel electrophoresis
Electric current us passed through the gel which allows band of small DNA fragments to be separated
Smaller fragments move quicker
Applications
Crime-determining if people were at crime scenes
Medical-father of child
Genetic screening
Is testing DNA for the presence or absence of a certain gene or an altered gene
Altered genes
Can altered by mutations
Do not have correct code for the production of protein
Genetic disorders caused by mutations- cystic fibrosis
What is genetic screening used for
Adult screening- see if they are carriers for a certain disease
Foetal screening- tested for genetic disorders
Nucleotide
DNA is made up of units called nucleotides
Long chain of nucleotides called polynucleotide
Structure of nucleotide
P
\
Deoxyribose—-A
What holds bonds together
Hydrogen bonds
Bonds between a bases
A and T form 2 weak hydrogen bonds
G and C form three hydrogen bonds
Purine (double ringed molecules)
Adenine and guanine
Pyrimidine bases (single ringed molecules)
Thymine and Cystosine
What scientists discovered DNA
Francis crick and James watson
RNA
Ribonucleic acid
Consists of four bases
Uracil instead of thymine
Single stranded
Differences between DNA and RNA
DNA
Has bases AT GC
Double stranded
Found in the nucleus
RNA
Has the bases AU GC
Single stranded
Found in nucleus and cytoplasm
Major steps I protein synthesis
Transcription=making of mRNA from DNA
Translation=making of protein depending on the RNA code
Three types of RNA
Messenger RNA mRNA
Transfer RNA tRNA
ribosomal RNA rRNA
Steps Involved in protein synthesis
Enzymes start to unwind the DNA double helix
Complimentary RNA bases join to the exposed DNA strand-transcription
Enzyme RNA polymerase joins the RNA bases together to form mRNA
mRNA moves from the nucleus to cytoplasm
rRNA are found in the ribosome
mRNA then moves into the ribosome and forms a weak bond with rRNA
tRNA is found in the cytoplasm, contains an anticodon attached to an amino acid
tRNA is attached to the mRNA in the ribosome
The anticodon on the tRNA compliments the codon on the mRNA
As the tRNA attach to the mRNA in the ribosome it also brings with it an animal acid
As the tRNA continue to enter the ribosome the amino acids detach from the tRNA and bond together to form a protein
tRNA leave the ribosome without any amino acids and pull with it the mRNA strand out of ribosome
Process stops when stop codon has been reached
