DNA/RNA
Discovery of DNA
*In 1953, Watson and Crick (along with Maurice Wilkins) discovered the shape *They won a Nobel Prize for their discovery
Replication of DNA
The DNA in the chromosomes is copied in a process called DNA replication
3 Types of RNA that help build proteins
1)Messenger RNA (mRNA): brings instructions from DNA in the nucleus to the cytoplasm, then to the ribosome. 2)Ribosomal RNA (rRNA), binds to the mRNA and uses the instructions to assemble the amino acids in the correct order (most abundant) 3)Transfer RNA (tRNA) is the supplier. Transfer RNA delivers amino acids to the ribosome to be assembled into a protein.
Codons for the genetic code
3 nitrogenous bases in mRNA code for one amino acid. Each group is known as a codon
Codons for the genetic code
64 combinations are possible when a sequence of three bases is used; thus, 64 different mRNA codons are in the genetic code.
Protein Synthesis: Making proteins
A chain of amino acids is formed until the stop codon is reached on the mRNA strand. UAA, UGA, & UAG are stop codons
The Genetic Code
A code is needed to convert the language of mRNA into the language of proteins.
A-T
AshleyTisdale
Shape of DNA
Because it is composed of 2 strands twisted together, its shape is called double helix.
Replication of DNA
Before a cell can divide by mitosis or meiosis, it must first make a copy of its chromosomes.
Difference in RNA from DNA
Both contain 4 nitrogenous bases, DNA has thymine, RNA contains a similar base called uracil (U). Uracil will pair with adenine in RNA
Genes and Proteins
By encoding the instructions for making proteins, DNA controls cells.
The structure of nucleotides
DNA is a polymer made of repeating subunits called nucleotides
Replication of DNA
DNA is copied during interphase (S phase) prior to mitosis and meiosis. It is important that the new copies are exactly like the original molecules.
Replication of DNA
Example- If you have a strand of DNA that is A - T - C - A - A - G You would get a strand replicated of T - A - G - T - T - C
Transcription
Example- If you have a strand of DNA that is A - T - C - A - A - G You would get a strand transcribed of U - A - G - U - U - C
What is DNA?
Genetic information that ultimately determines an organism's traits.
G-C
George Clooney
Cytosine (C) always pairs with
Guanine (G)
Mutation
If there is a change in any nucleotide sequence at even 1 location, it would cause serious repercussions
Translation: From mRNA to Protein
It "translates" a message from the language of nucleic acids into polypeptides.
RNA
It acts like a messenger between DNA and ribosomes and carries out the process of making proteins from amino acids
What is DNA?
It determines the structure of proteins (all actions depend on proteins called enzymes which controls all functions)
Difference in RNA from DNA
Sugar in RNA is ribose; DNA's sugar is deoxyribose.
What is DNA?
It is the complete instructions for manufacturing all the proteins for an organism.
Transcription
It is the process where RNA is made from DNA
Shape of DNA
It looks like a spiral staircase
Nucleotides have three parts:
One of 4 nitrogenous bases (adenine, guanine, cytosine, thymine)
Genes and Proteins
Proteins are polymers of amino acids.
The Genetic Code
Proteins contain chains of amino acids. The language of proteins uses an alphabet of amino acids.
Genes and Proteins
Proteins control chemical reactions that perform key life functions.
RNA
RNA is like DNA, it is a nucleic acid and is transcribed from DNA
Difference in RNA from DNA
RNA is single stranded, DNA is double stranded.
Transcription
The main difference between transcription and DNA replication is that transcription results in the formation of one single-stranded RNA molecule rather than a double-stranded DNA molecule.
The Genetic Code
The nucleotide sequence transcribed from DNA to messenger RNA acts as a genetic message to build a protein.
Shape of DNA
The phosphate groups and deoxyribose molecules form the backbone of the chain, and the nitrogenous bases stick out like the teeth of a zipper.
Translation: From mRNA to Protein
The process where transfer RNA picks up and carries amino acids from the messenger RNA at the nucleus and carries them to the ribosomes
Genes and Proteins
The sequence of nucleotides in each gene contains information for assembling the string of amino acids that make up a single protein.
There are always equal amounts of adenine as there is thymine
There are always equal amounts of cytosine as there is guanine
Adenine (A) always pairs with
Thymine (T)
Protein Synthesis: Making proteins
Usually, the first codon on mRNA is AUG, it signals the start of protein synthesis
Protein Synthesis: Making proteins
When this signal is given, the ribosome slides along the mRNA to the next codon.
Replication of DNA
Without DNA replication, new cells would have only half the DNA of their parents.
Nucleotides have three parts:
a phosphate group
Nucleotides have three parts:
a simple sugar which is deoxyribose (DNA name is deoxyribonucleic acid.)
