LB145 Sec 001-004

1. LB145Sec 001-004

2. Today’s Outline • Announcements: Homework #3 is due on Thursday. Flexible Grade Weightings due TODAY! Honors option meeting: 8:15-8:45am on Monday (see website) • Calvin Cycle (a human experiment) • Mendel’s Peas

3. Fig. 10-17 STROMA (low H+ concentration) Cytochrome complex Photosystem I Photosystem II Light 4 H+ NADP+ reductase Light 3 Fd NADP+ + H+ NADPH Pq Pc e– 2 e– H2O O2 1/2 1 THYLAKOID SPACE (high H+ concentration) 4 H+ +2 H+ To Calvin Cycle Thylakoid membrane ATP synthase STROMA (low H+ concentration) ADP + ATP P i H+

4. Fig. 10-5-4 CO2 H2O Light NADP+ ADP + P i Calvin Cycle Light Reactions ATP NADPH Chloroplast [CH2O] (sugar) O2

6. The Calvin Cycle

8. 3.0 Photosynthesis and Mendel

9. 3.1 Mendel’s Experiments • Gregor Mendel – the father of modern genetics. • Inheritance of traits in pea plants (P. sativum). • Flower color, seed shape, pod shape, pod color, flower position, stem length, embryo color.

10. 2.1 The Evolution of Wrinkled Peas Wrinkled peas aren’t just wrinkled… Round Wrinkled

11. 2.2 The Evolution of Wrinkled Peas They taste good too! Round Wrinkled

12. 1.1 Fact Sheet: Pisumsativum • Common names: Field peas. • Native to: Near East  Iraq, Turkey, Israel, Palestine, etc. • A key crop of the Neolithic Agricultural Revolution, oldest recorded samples date to 10,000 BCE.

13. 3.3 Inheritance of Pea Plant Traits • In pea plants, traits are often controlled by one set of alleles. These alleles can combine in a homozygous (dominant or recessive) or heterozygous fashion depending on parental alleles. • Examples: • The Round vs. Wrinkled pea trait is controlled by the alleles R and r • The Yellow vs. Green pea trait is controlled by the alleles Y and y.

14. 3.5 From Traits to Genes • Amazingly, Mendel had no knowledge of DNA, genes or chromosomes. • The traits (alleles) that Mendel described correspond to specific genes within the pea plant genome.

15. Molecular Biology: Central Dogma The “R” allele of the sbe1 gene codes for the SBE1 protein. The SBE1 protein is an enzyme that converts simple starch (amylose) to complex starch (amylopectin). How does it all work?

16. 2.4 Inside the Pea Cell: Sugar and Starch

17. Fig. 10-17 STROMA (low H+ concentration) Cytochrome complex Photosystem I Photosystem II Light 4 H+ NADP+ reductase Light 3 Fd NADP+ + H+ NADPH Pq Pc e– 2 e– H2O O2 1/2 1 THYLAKOID SPACE (high H+ concentration) 4 H+ +2 H+ To Calvin Cycle Thylakoid membrane ATP synthase STROMA (low H+ concentration) ADP + ATP P i H+

18. Fig. 10-5-4 CO2 H2O Light NADP+ ADP + P i Calvin Cycle Light Reactions ATP NADPH Chloroplast [CH2O] (sugar) O2

19. The Calvin Cycle

20. 2.4b Inside the Pea Cell: Sugar and Starch Glyceraldehyde 3-phosphate

21. 2.4c Inside the Pea Cell: Sugar and Starch G3P Fructose biphosphate aldolase Fructose 1,6-biphosphate Fructose 6-phosphate Fructose biphosphase Hexose-phosphate isomerase ADP-glucose phosphorylase Glucose 1-phosphate Glucose 6-phosphate ADP-Glucose Phosphoglucomutase

22. 2.4d Inside the Pea Cell: Sugar and Starch Starch synthetase ADP-Glucose Starch branching enzyme Amylose Amylopectin

23. Starch-branching enzyme

24. Sucrose

25. 2.1 The Evolution of Wrinkled Peas Wrinkled peas aren’t just wrinkled…they taste good too! Round (R allele of sbe1 gene) Wrinkled (r allele of sbe1 gene) G3P (Intermediates)AmyloseAmylopectin G3P (Intermediates)Amylose  Sucrose functioning starch branching enzyme non-functioning starch branching enzyme

26. 2.9 Question: What do seed shape and seed taste have in common? • Wrinkled peas are wrinkled because they have a higher water content than round peas. When they dry, round peas retain their shape while wrinkled peas do not due to water loss. Think and Write Down an Answer: • Why would wrinkled (sweet) peas have a higher water content than round (starchy) peas? Discuss your answer with your neighbor (2 mins) • Name cards will be used to find out what your team thought.

27. 4.0 In Detail: The Genetics ofRound and Wrinkled Peas …. SEE LB145 UNIT 3

28. 5.0 The Artificial Selection ofRound and Wrinkled Peas

29. 5.1 Artificial Selection of Sweet Peas • Wrinkled peas are sweeter and in ancient times farmers tended to select them for breeding.

30. 5.2 Artificial Selection: • Consider two fields with pea plants. • Some plants produce wrinkled peas, others produce round peas (50% wrinkled peas, 50% round peas).

31. 5.3 Artificial Selection: • Question: assuming you were a farmer and could weed out wrinkled peas or round peas, would it be easier to create a permanent monoculture of round peas or a permanent monoculture of wrinkled peas?

32. 5.4 Artificial Selection: • From a mixed field, what is easier to facilitate through artificial selection? Monoculture of (dominant) round peas. Monoculture of (recessive) wrinkled peas. Both scenarios have equal difficulty.

33. 5.5 Darwin and Selection • Darwin used the example of artificial crop selection as an example to support his theory of natural selection.

34. For THURSDAY: • Homework #3 – the Photo Problem • StudyNotes 4 is due on Tuesday Feb 12th.