What is a gene, and what does that have to do with

evolution?

CB 6.9

An Animal Cell

Videos:http://www.microscopyu.com/moviegallery/livecellimaging/a549/index.htmlhttp://sunflower.bio.indiana.edu/~rhangart/plantmotion/starthere.html

Information flow in cells

Protein

CB 5.25

Proteins are the “doers” of the cell.They act as:•Enzymes•Structural Support•Transporters•Signals

Genes code for proteins…

Chains of DNA can store information:

Information flow in cells

Protein

CB 5.25

CB 5.17The basic structure of amino acids

CB 5.17

the20 AminoAcids

CB 5.20Amino acids connect together to make proteins.

CB 5.20

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

CB 19.14

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 Tenhttp://www.youtube.com/watch?v=BBsOeLcUARw

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

Five Perspectives about Genes:

1. Genes act as units of heredity

2. Genes are seen as a cause of disease

3. Genes code for proteins

4. Genes act as switches, controlling

development

5. Genes are replicators (selfish gene)

CB 16.2Visualizing the perspectives about genes

Different strains of bacteria are injected into mice.

CB 16.2 Visualizing the perspectives about genes

CB 16.2 Visualizing the perspectives about genes

CB 16.2

What has happened to the bacteria?

Visualizing the perspectives about genes

CB 16.2

1. Genes act as units of heredity2. Genes are seen as a cause of disease3. Genes code for proteins4. Genes act as switches, controlling

development5. Genes are replicators (selfish gene)

Visualizing the perspectives about genes

CB 5.25

Genes are the parts of DNA that contain information.

Protein

CB 16.7In cells, DNA is a double-stranded helix

Five Definitions of Genes:

1. Genes act as units of heredity

2. Genes are seen as a cause of disease

3. Genes code for proteins

4. Genes act as switches, controlling

development

5. Genes are replicators (selfish gene)

CB 5.17

?

4 nucleotides in DNA

20 amino acids in proteins

CB 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.

CB 17.4

Combinations of 3 nucleotides code for each 1 amino acid in a protein.

CB 17.5

the Genetic Code

Changes in DNA can change the protein

Changes in DNA can change the protein

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

CB 17.4

Combinations of 3 nucleotides code for each 1 amino acid in a protein.

Protein

How is DNA used to make proteins and RNA?

Both proteins and RNA are involved in the processes.

CB 5.25

Differences between DNA and RNA

Protein

How is DNA used to make proteins and RNA?

Both proteins and RNA are involved in the processes.

CB 5.25

CB 5.25

Genes act as switches.

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

CB 5.25Genes contain the information to make RNA and/or proteins.

Genes act as switches.

The information in genes is what to make and when to make it. Protein

1. Genes act as units of

heredity

5. Genes are replicators

(selfish gene)

For life to exist, the information (genes) must be passed on.

CB 13.5

CB 13.5

As organisms reproduce the DNA is passed on to the next generations.