DNA + RNA Flashcards
heredity
the passing on of features from parents to offspring by means of genes
where is dna found
nucleus, mitochondria, chloroplast
chemical composition of a chromosome
protein + DNA
what is the ratio of DNA to protein
dna 40% + Protein 60%
what is the protein in a chromosome called
histones
what is the function of protein in chromosomes
to keep the DNA tightly packed to fit in the nucleus
where are genes located on the chromosome
along the strands of DNA
genes
section of DNA that codes for the production of a protein
non coding DNA
DNA that does not code for the formation of a protein ie junk DNA
how much of DNA is composed of genes
3%
the rest is useless
what does DNA stand for
deoxyribonucleic acid
what are the 4 bases in DNA
adenine
guanine
cytosine
thymine
What type of bonding joins the complimentary bases
Hydrogen bonds
Complimentary base of adenine
Thymine
Complimentary base of guanine
Cytosine
What is the shape of a DNA structure
2 parallel strands with several steps across
What is the function of non coding dna?
Unknown
What a nucleotide
A piece of strand that accompanies a base
What are the 3 parts of a nucleotide
Phosphate group
Deoxyribose
And a nitrogenous base Ie AGCT
Which part of a nucleotide has to be drawn in the middle?
Deoxyribose
What bases are purines
Adenine + Guanine
Which bases are pyrimidines
Thymine + cytosine
Genetic code
The sequence of bases that give instruction to the cell to make a certain protein
When do genes work
When they are sent into the cytoplasm using RNA to make a certain protein
Where is protein made?
Ribosomes
How many consecutive bases along DNA code for one amino acid
3
What is a codon or a triplet
3 consecutive bases along DNA that code for one amino acid
How many codes are in a gene
200 codes for up to 20 amino acids
Replication
The production of an identical copy of DNA
When does DNA replication occur?
Interphase
What controls DNA replication
Enzymes
What does DNA replication require to happen
Energy
What is the process of DNA replication
-Double helix unwinds + helicase breaks bonds between base pairs
-free nucleotides move into nucleus and attach to exposed complimentary bases
-2 og strands act as a template for new DNA. 2 identical strands are produced
-the new double strands rewind forming a double helix
- one side of each new DNA molecule comes from the OG and 1 is new. Genes of each chromosome are the exact same
DNA Profiling
The process of making a pattern of bands from a persons DNA to compare with other DNA patterns
How do you prepare a DNA profile?
-DNA is extracted from cells by breaking cell membrane and isolating DNA
- DNA is cut into fragments by restriction enzymes
- fragments are separated by size by gel electrophoresis
- patterns are analysed and compared
What are 2 uses of DNA profiling
Crime Ie biological samples like fingerprints
Medical ie paternity testing
Genetic screening
The testing DNA for the absence of presence of a specific gene or altered gene
Give 2 uses of genetic screening
To see if a person is carrying genes that may cause a disease
Or
To see if a person has one copy of a gene for a genetic disorder that they could pass onto their children
What does RNA stand for
Ribonucleic acid
What are the differences between DNA and RNA
DNA:
Double stranded
Contains thymine
Contains deoxyribose
Only 1 type
RNA
Single stranded
Contains uracil
Contains ribose
3 types
What are the 3 types of RNA
mRNA tRNA rRNA
What are the 2 mains steps of protein synthesis
Transcription and translation
Where does transcription occur
Nucleus
Where does translation occur
Ribosomes
What is transcription
The copying of a sequence of genetic bases from DNA onto messenger RNA
What is mRNA’s function
Messenger, makes a copy of the genetic message
Where does mRNA function
Nucleus
What does the m in mRNA stand for
Messenger
What does the r in r RNA stand for
Ribosomal
What does the t in tRNA stand for
Transfer
Where does rRNA function
Ribosome
What is rRNA’s function
Used as a template to make protein
Used to attach tRNA to mRNA
Where does tRNA work
Ribosome
What is the function of tRNA
Places amino acids in correct sequence to make a protein
What is translation
The manufacture of protein by converting the sequence of genetic bases from mRNA into a chain of amino acids
Describe the process of translation
-mRNA moves into ribosomes
- mRNA forms a weak bond with rRNA
-tRNA is attracted to mRNA in ribosome
- after start codon, tRNA releases its amino acid in ribosome
-correct sequence and folding is needed for correct function of protein
describe the process of transcription
-complementary RNA nucleotides join an exposed strands of DNA
-RNA polymerase join RNA nucleotides to form mRNA
-start codon begins the genetic info to be transcribed
-stop codon signals for genetic material to stop being transcribed and forms a gene.
