Post on 05-Jan-2016
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Today: How do genes work?
Discussions begin/began this week.
Homework #1 posted
Information flow in cells
Protein
Fig 5.26
Fig 5.21
Proteins are a string of amino acids
Proteins are the “doers” of the cell.They act as:•Enzymes•Structural Support•Transporters•Signals
a gene - DNA used to produce RNA or protein
The relationship between DNA and genes
promoter coding region terminator non-geneDNA
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.
Width of DNA
Length of human DNAin each cell
The length of DNA in each of your cells is longer than you are tall.
Power of ten:http://www.youtube.com/watch?v=A2cmlhfdxuY
Fig 6.2
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.
a gene - DNA used to produce RNA or protein
The relationship between DNA and genes
promoter coding region terminator non-geneDNA
fig 5.17
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4 nucleotides in DNA
20 amino acids in proteins
fig 16.5
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 42:1 42 16
How can 4 nucleotides code for 20 amino acids?
IF
Ratio(nucleotide:amino acid) Possible combinations
1:1 41 42:1 42 163:1 43 64
How can 4 nucleotides code for 20 amino acids?
IF
Ratio(nucleotide:amino acid) Possible combinations
1:1 41 42:1 42 163:1 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
Fig 17.22
Changes in DNA can change the protein
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.
The atc ata tet her at.
delete one letter
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
a gene
Genes have three basic parts
promoter coding region terminator non-geneDNA
fig 5.26Genes 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.
Genes are replicators(selfish gene)
fig 21.7
fig 19.4
Viruses infect living cells, take over, and produce more virus.
Bodies are vessels for the transmission of genes
Transposons
fig 21.8
Genes are replicators (selfish gene)
Transposons: mobile DNA
fig 21.9
Barbara McClintock, discoverer of transposons
fig 21.8
Genes are replicators (selfish gene)
Transposons: mobile DNA
fig 21.9
Retrotransposons: mobile and self-replicating DNA
fig 21.9
Genes are replicators(selfish gene)
fig 21.7
Next: How do your genes make you, you?
Discussions begin/began this week.
Homework #1 posted