DNA AND RNA Flashcards
What does DNA stand for.
Detoxribonucleic acid
Where is DNA found
Nucleus of a cell
Can also be found in the mitochondria and chloroplast
How does the DNA for in the nucleus
It can coil and fold
How many strands does DNA have
2
What are the four bases used in DNA
A - adenine
t - thymine
G- guanine
C- cytosine
What two pairs of bases join together
A+T
G+C
What shape does DNA have
Double helix
What is a gene
A section of DNA that causes the production of a protein
How many amino acids are used in the production of a protein
20
What does a gene carry
Different codes to control the formation of different amino acids
What do genetic codes have
For each amino acid they have a sequence of three bases
What are a sequence of three bases known as
A triplet / Codon
What is the sequence for
valine
Alanine
CAA
CGA
What are non coding DNA
They do not have a code for the formation of a protein- also known as DNA junk
What happens during DNA replication
When mitosis occurs one cell divides into two identical daughter cells.
Why does the replication occurs
So there is an exact copy of the DNA for mitosis to occur
Where does the mitosis take place
Interphase
How does DNA replication occur
The double helix unwinds
Enzymes break the bond between the base pairs
Other DNA bases now enter the nucleus and join with the exposed DNA strand
Each new strand is identical to the original strand.
What is DNA profiling
It is a method of making unique pattern of bands from DNA of a person which is then used to tell the difference of that DNA from the other DNA
What is the method of DNA profiling
DNA is released
San is cut into fragments
Fragments are separated
Patterson are compared
How is the DNA released
By the breaking down of the cell
How is the DNA cut into fragments
Using enzymes
They will be different lengths because if the different distances between the base sequences
How are the fragments separated
Based on their size
By a process called gel electrophoresis
An electric current is passed through the gel which allows bands of small DNA fragments to be separated from larger DNA fragments
When might DNA profiling be used
To determine suspects of a crime
To determine if someone is the parent of a child
What is genetic screening
Testing DNA for the presence or absence of a certain gene or an altered gene
How can genes be altered
By mutations
Or genetic disorders : cystic fibrosis. Albinism
What are altered genes
They do not have the correct code for the production of a protein
When is genetic screening used
On people who have genetic disorders, tells them the chances that their children will get these
Foetal screening, cells can be removed from get placenta of a foetus
What ethical issue does genetic screening bring
Mothers determine if their unborn child has a genetic disorder
What is a nucleotide
DNA made up of units called nucleotides
What is a long chain of nucleotides called
Polynucleotide
What is a nucleotide made up of
Phosphate —- sugar —- nitrogen base
What are the symbols of the structure of a polynucleotide I
Sugar is a deoxyribose : D
Phosphate : P
Nitrogen base : A or G or T or C
What holds bases together
Hydrogen bond
What for, two weak hydrogen bonds
Adenine and thymine
What forms three hydrogen bonds
Guanine and cytosine
What are the four nitrogen bases know as
Two = purines Two = pyrimidine
What are the two purine bases
Double ringed molecules - A and G
What are the pyrimidine bases
Single ringed molecules T and C
What scientists discovered the shape and structure of DNA
France’s crick and James Watson
What is protein synthesis
The making of a protein
What is the method of protein synthesis
Enzymes start to unwind the DNA
Complimentary RNA bases join to the exposed DMA strand (transcription)
The enzyme RNA polymerase joins the RNA bases together to form mRNA
MRNA moves from the NUCELUS to the cytoplasm
rRNA are found in the ribosomes
mRNA the moves into the ribosome and then forms a weak bond with the rRNA
tRNA is found in the cytoplasm
tRNA contains an anticodon attached to an amino acid
tRNA is attracted 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 bring with it an amino acid
As the tRNA c
What is the making of mRNA from DNA
Transcription
What is the making of a protein depending on the RNA code
Translation
What are the major steps involved in protein synthesis
Transcription and
Translation
What are the three types of RNA involved in the production of a protein
Messenger RNA
TRANSFER RNA
ribosomal DNA
ALL PRODUCED IN THE NUCELUS
What does each strand of messenger RNA have
A start codon
A series of codon
Stop codon
What is the definition of heredity
The passing on of features from the parents of offspring by the means of genes
What is a gene expression
Is the way in which the genetic information in a gene is decoded in the cell and used to make a protein
What are characteristics
Traits that are inherited genetically
What is an anticodon
Is a sequence of three bases on tRNA that are complementary to a sequence of three bases on mRNA.
What is the function of mRNA
Complementary strand to DNA
Carries instruction of the production of a protein from DNA to a ribosome
What function has tRNA
Has a complementary anticodon to mRNA codon
Carries an amino acid to the ribosome
What function has rRNA
Forms part of the structure of the ribosome
Forms a weak bind with mRNA in the ribosome
What are chromosome composed of
60% protein
40% DNA
What are the differences between DNA and RNA
DNA
- double strand
- Sugar is deoxyribose
- Much longer
- Has thymine
- Self replication
- Only in the nucleus
RNA
- Single strand
- Sugar is ribose
- Has uracil
- Shore molecule
- Not self replicating
- Found in nucleus and cytoplasm.
What is heredity
Posting on of features from parents to offspring by means of genes
What can plants inherit
Number of petals
Colour
What is a gene
Section of DNA that causes the production of a protein
What is gene expression
The way in which the genetic information in a gene is decoded in the cell to make a protein
What does the expression of a gene do
Produces the characteristics of traits that are inherited
What effects genese
If the nutrients aren’t supplied for it eg sunlight
What are characteristics
Traits or features that are inherited genetically
What are chromosomes made of
60 protein
49 DNA
What is the protein responsible for in a chromosome
Holding the DNA
What % of chromosomes are non coding DNA
97
What’s the genetic code
Sequence of bases in DNA that provide the instruction for a cell (using RNA) to form a protein
When is a code sent to
Cytoplasm
What is a gene
a section of DNA that instructs a cell to form a particular protein
What is a triplet or codon
Sequence of three bases in DNA that act as a code for an amino acid
During DNA replication where do the DNA base pairs come from
Normally present in be cytoplasm enter the nucleus
Method of preparing a DNA profile
1, DNA is released from the cells
- DNA is cut into fragments of different lengths
- They are separated according to size
- Pattern is analysed
What is a DNA profile
Method of making a unique pattern of bands from DNA of. A person which can then be used to compare with a DNA profile of another person.
How is the isolation DNA cut into fragments
Using restriction enzymes
How are the fragments separated
Using gel electrophoresis
What is forensic medicine
The way in which medical knowledge is used in legal situations
How does DNA screening work
Addicting a radioactive section of DNA to a sample of DNA from the person being tested the DNA will only attach to a normal gene
What is foetal screening
Cells can be removed from the embryo placenta it fluid around the foetus and tested to detect is the embryo has any genetic disorders
How does DNA and RNA differ
RNA is based on the sugar ribose
RNA consists of 4 bases - A U G C
RNA IS SINGLE STRANDED
RNA can move out of the nucleus and into the cytoplasm
What happens in protein synthesis
The sequence of bases on a DNA strand carries instructions to form a particular protein
The DNA separates (nucleus)
RNA bases attach to the exposed bases on the side of the DNA (TRANSCRIBED)
mRNA strand detaches from the DNA and moves from the nucleus to the cytoplasm and through a ribosome where is it TRANSLATED into the correct sequence of amino acids
The protein becomes folded as it emerges from the ribosome
What are the classifications of the bases in DNA
Purines
Pyrimidines
What are purines
Double ring molecules (A AND G)
What are pyrimidines
Single ring T AND C
What hold base pairs
Hydrogen bonds
Where does the DNA double helix unwind
The site of the gene that is going to produce a protein
What causes the sequence of RNA bases to join together to form messenger RNA
DNA polymerase
What is an anticondon
Sequence of three bases on tRNA that are complementary to a sequence of three bases on mRNA
