Today How do genes work Discussions beginbegan this
Today: How do genes work? Discussions begin/began this week. Homework #1 posted
Fig 5. 26 Information flow in cells Protein
Proteins are the “doers” of the cell. They act as: • Enzymes • Structural Support • Transporters • Signals Fig 5. 21 Proteins are a string of amino acids
The relationship between DNA and genes a gene - DNA used to produce RNA or protein promoter coding region terminator non-gene DNA
Only a small percent of DNA codes for proteins Fig 21. 7
DNA Composition: In humans: • Each cell contains ~6 billion nucleotides of DNA. • This DNA is ~2 meters long and 2 nm wide. • ~98% does not directly code for amino acids • In a single human cell only about 3 -5% of genes are expressed at a time.
Fig 6. 2 Length of human DNA in each cell The length of DNA in each of your cells is longer than you are tall. Width of DNA Power of ten: http: //www. youtube. com/watch? v=A 2 cmlhfdxu. Y
DNA Composition: In humans: • Each cell contains ~6 billion base pairs of DNA. • This DNA is ~2 meters long and 2 nm wide. • ~1. 5% directly codes for amino acids • ~25% is genes • In a single human cell only about 5 -10% of genes are expressed at a time.
The relationship between DNA and genes a gene - DNA used to produce RNA or protein promoter coding region terminator non-gene DNA
4 nucleotides in DNA ? fig 16. 5 20 amino acids in proteins fig 5. 17
How can 4 nucleotides code for 20 amino acids? IF Ratio (nucleotide: amino acid) Possible combinations 1: 1 41 4
How can 4 nucleotides code for 20 amino acids? IF Ratio (nucleotide: amino acid) Possible combinations 1: 1 41 4 2: 1 42 16
How can 4 nucleotides code for 20 amino acids? IF Ratio (nucleotide: amino acid) Possible combinations 1: 1 41 4 2: 1 42 16 3: 1 43 64
How can 4 nucleotides code for 20 amino acids? IF Ratio (nucleotide: amino acid) Possible combinations 1: 1 41 4 2: 1 42 16 3: 1 43 64 • There are more possible combinations than amino acids.
fig 17. 4 Combinations of 3 nucleotides code for each 1 amino acid in a protein.
Differences between DNA and RNA Fig 5. 27
fig 17. 4 Combinations of 3 nucleotides code for each 1 amino acid in a protein.
fig 17. 5 the Genetic Code
Changes in DNA can change the protein Fig 17. 22
Changes in DNA can change the protein. . . sickle-cell anemia
The fat cat ate the rat. change one letter The zat cat ate the rat.
The fat cat ate the rat. change one letter The zat cat ate the rat. delete one letter The atc ata tet her at.
fig 17. 4 Combinations of 3 nucleotides code for each 1 amino acid in a protein.
fig 5. 26 The information in genes is what to make and when to make it. Protein
Genes have three basic parts a gene promoter coding region terminator non-gene DNA
fig 5. 26 Genes contain the information to make RNA and/or proteins. The information in genes is what to make and when to make it. Protein
When to make a protein is critical for proper development.
fig 21. 7 Genes are replicators (selfish gene)
fig 19. 4 Viruses infect living cells, take over, and produce more virus.
Bodies are vessels for the transmission of genes
fig 21. 8 Transposons
Genes are replicators (selfish gene) Transposons: mobile DNA fig 21. 9
fig 21. 8 Barbara Mc. Clintock, discoverer of transposons
Genes are replicators (selfish gene) Transposons: mobile DNA fig 21. 9
Retrotransposons: mobile and self-replicating DNA fig 21. 9
fig 21. 7 Genes are replicators (selfish gene)
Next: How do your genes make you, you? Discussions begin/began this week. Homework #1 posted
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