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Homework #1 is due now Bonus #1 is posted and due 10/24. Fig 8.11. DNA contains the information to make RNA and/or proteins. Protein. General model of Ca ++ signaling. in Plants Development Cold Guard cell closing Osmotic shock Light Fungal infection Touch Pollen tube growth
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Homework #1 is due now Bonus #1 is posted and due 10/24
Fig 8.11 DNA contains the information to make RNA and/or proteins. Protein
in Plants Development Cold Guard cell closing Osmotic shock Light Fungal infection Touch Pollen tube growth Wounding… in Animals Neurons Muscle movement Wounding Development Fertilization Hormones … Ca++ is involved in signal transduction for responses of: How can there be specificity?
2 hypotheses about how Ca++ signals are transduced: Signatures vs. Switches Fig 1. Scrase-Field and Knight, Current Opinion in Plant Biology 2003, 6:500–506
Stomata regulate gas exchange: CO2 in, O2 and water out H2O H2O
Stomata open closed
Ca++ fluxes in guard cells in response to hormone or stress that cause stomatal closing. Wildtype vs. det3 and gca2: mutants that fail to close stomata following treatment Fig 5. Sanders et al., The Plant Cell, S401–S417, Supplement 2002
Stomata aperture in response to Ca++ spikes: More spikes= more closing Fig 1. Allen et al., Nature, Vol 411:1053-1057, 28 June 2001
Spike timing is critical for response Fig 2. Allen et al., Nature, Vol 411:1053-1057, 28 June 2001
Duration of spikes for stomata closing Fig 2. Allen et al., Nature, Vol 411:1053-1057, 28 June 2001
2 hypotheses about how Ca++ signals are transduced: Signatures vs. Switches Fig 1. Scrase-Field and Knight, Current Opinion in Plant Biology 2003, 6:500–506
Signal transduction – such as changes in cellular components or production of new cellular components
Fig 8.11 How do cells express genes?
Fig 8.3 The relationship between DNA and genes a gene promoter coding region terminator non-gene DNA
Combinations of 3 nucleotides code for each 1 amino acid in a protein.
Fig 8.4 • Overview of transcription Figure 8-4
Fig 7.5 +8.2 Each nucleotide carbon is numbered
Fig 7.8 Each nucleotide is connected from the 5’ carbon through the phosphate to the next 3’ carbon.
Each nucleotide is connected from the 5’ carbon through the phosphate to the next 3’ carbon. Fig 7.8
Fig 8.4 What is so magic about adding nucleotides to the 3’ end?
How does the RNA polymerase know which strand to transcribe? Fig 8.8
Reverse promoter, reverse direction and strand transcribed. RNA 5’ 3’ 5’ 3’ 5’
Why do polymerases only add nucleotides to the 3’ end? RNA RNA DNA DNA U U
5’ 3’ Incoming nucleotide Hypothetically, nucleotides could be added at the 5’ end.
Error P P-P
Error P The 5’ tri-P’s can supply energy for repair U P-P-P P
Incoming nucleotide Error repair on 5’ end not possible. 5’ 3’
Need for error repair limits nucleotide additions to 3’ end. RNA RNA DNA DNA U U
Fig 8.11 DNA contains the information to make RNA and/or proteins. Protein
Homework #1 is due now Bonus #1 is posted and due 10/24