Unit 3 Flashcards
DNA
Deoxyribonucleuic acid, double helix structure, contains sugar deoxyribose, located in nucleus, template for synthesis of proteins, stores genetic information
RNA
Ribonucleic acid, contains sugar ribose, DNAs helper molecule, single stranded, located everywhere (including nucleus and cytoplasm), transcribes the template, carries DNA message code, helps make protein, has more than one type
Nucleotides (nucleobases)
Sugar- ribose or deoxyribose
Phosphate group- acidic
Nitrogen base- A, G, C, T or U
Types of RNA
Messenger RNA
Transfer RNA
Ribosomal RNA
Protein synthesis
2 Stages:
Transcription- rewrites and transcribes it
Translation- genetic code is translated into a new language, protein language
Transcription
A process of copying the DNA nucleotide sequence into mRNA (messenger RNA)
Translation
A process of translating mRNA strand into a series of amino acids that will join together to form a protein, mRNA is now outside the nucleus and sectioned into codons (triplets), tRNA brings amino acids to the mRNA strand, tRNA has an anticodon that pairs up with the mRNA codon
Purines
Nitrogen bases Adenine and Guanine that have 2 rings
Pyrimidines
Nitrogen bases thymine and cytosine that have only 1 ring
Base Pairing Rules
Adenine always bonds with Thymine (A=T), Guanine always bonds with Cytosine (G=C), connected by hydrogen bonds
Phosphodiester bond
Bond between the phosphate group of 1 nucleotide and the sugar of another
DNA Nitrogen Bases
Adenine, Cytosine, Thymine and Guanine
RNA Nitrogen bases
Adenine, Cytosine, Guanine, Uracil
Oswald Avery
Averys team determined genes are composed of DNA
Erwin Chargaff
Discovered that DNA has the same amount of adenine as Thymine and the same amount of cytosine as Guanine
Rosalind Franklin and Maurice Wilkins
Used X-ray to discover DNA was a double helix (spiral)
Watson and Crick
Won Nobel Prize for discovering and creating the structural model of DNA, they credited Wilkins and Franklin, Wilkins also received a nobel prize
Gene mutations
Changes made to an organism’s genetic material, change may occur due to error in replication/transcription, radiation, viruses and other things, occur on a small scale (gene) or large scale (chromosome)
Silent mutations
Changes that don’t result in a change to the organism
Small scale mutations
3 main types that affect 1 nucleotide in a DNA triplet (Point Mutation):
- Reversal/Substitution
- Insertion
- Deletion
Point mutations
Small scale mutation that occurs when a single nucleotide in a gene is exchanged for another nucleotide (for ex; A for T or C for G), have an effect on protein synthesis but only one DNA triplet is altered which effects 1/more codons and therefore one/more amino acids
Chromosome
Rod shaped, filamentous body in the nucleus, becomes visible during cell division (not visible in active nucleus bc of high water content), carried of genes
Number of chromosomes
Humans have 46
Constant for each cell in body (except sex cells have half amount)
Constant through life of an individual (never lose/gain them)
Constant for all species
Identify chromosomes
- Size
- Shape (position on centromere)
- Bonding patterns produced by specific stains
