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