AP Biology: Tuesday, 11/22/11Intro to Photosynthesis

Homework: Chapter 10 Reading Worksheet – take notes on this for tomorrow

Do Now: Hand in PS 9 Answer the following in your notebook:

Which stage of cell respiration do you think EVOLVED first? Why?

What do you know about the summary equation for photosynthesis? Can you write it? How does it relate to the equation for cell respiration?

Goals for Today: Explain the order of evolution of methods for using and making

sugar Identify the pigments and light wavelengths necessary for

photosynthesis, and use an absorption spectrum to explain which wavelengths of light best promote photosynthesis

Evolution of glucose pathways:

1. Glycolysis – slow, makes a little ATP from the glucose in the “primordial soup”

2. Photosynthesis Creates lots of glucose to fuel glycolysis Creates oxygen…

3. Aerobic Cell Respiration

Photosynthesis

Carbon dioxide + Water + Sunlight energy

Glucose + Oxygen

Photosynthesis:Sunlight meets Chlorophyll

Visible Light SpectrumPigmentsChlorophyllAbsorption Spectrum

Goals: Identify the pigments and light wavelengths

necessary for photosynthesis Use an absorption spectrum to explain which

wavelengths of light best promote photosynthesis

In a group of 3-4:

Choose a scribe to record answers. Discuss and write down:

1. Why are plants green?2. Which color(s) of light would result

in the most photosynthesis?3. Which color(s) would result in the

least photosynthesis?4. How could you set up an

experiment to test this?

AP Bio: Wednesday, 11/23/11Photosynthesis

Homework: PS 10 due Thursday after break

Do Now: Take out the Photosynthesis Reading Worksheet Get back and look over your quiz

Goals for Today: Describe the details of the two stages of

photosynthesis How light energy is converted into chemical energy How that energy is used to make glucose

Summary of Photosynthesis:

Overall equation:

6CO2 + 6H2O + sunlight energy C6H12O6 + 6O2

reduction

oxidation

cuticle

upper epidermis

lower epidermis

Photosynthesis

electron carrier

electron carrier

electron carrier

Phase 1: The Light Reactions

Phase 1: The Light Reactionsstroma

thylakoid space

PS II PS I

ATP synthase

cytochromes(electron transport proteins) NADP+

reductase

e-

LIGHT

e-e-H2O ½ O2

+ 2 H+

e-e-e-e-

e-e-

H+

H+

H+

ADPPi

ATP

NADP+NADPH

to Calvin Cycle

LIGHT

Summary of Light Reactions:

• Water splits to donate electrons, and releases oxygen as waste

• Light excites electrons to flow through ETC made of chlorophylls (photosystems) and cytochromes

• ATP and NADPH are made (for use in the Calvin cycle)

Phase 2: Calvin Cycle

Phase 2: Calvin Cycle

Summary of Calvin Cycle:

• Carbon (from CO2) is fixed by the enzyme Rubisco

• Most fixed carbon is used to regenerate RuBP (the CO2 acceptor that starts the cycle)

• Some fixed carbon is used to make a 3-carbon sugar that can form…– glucose (used for cell resp. or stored as starch)– sucrose (transported through rest of plant)[This is the whole point of photosynthesis!]

Photosynthesis Video

AP Bio: Monday, 11.29.10Photosynthesis: Challenges & Adaptations

Homework: PS 10 due tomorrow

Do Now: Read the Background Info and answer questions 1-2 on the

handout Goals for Today:

Describe photorespiration and explain why it’s bad for plants Explain how C4 and CAM photosynthesis get around the

challenge of photorespiration Agenda:

Do Now Quick explanation of photorespiration Work in groups on C4 or CAM If time: Present on C4 or CAM. If not, tomorrow.

Photorespiration –

The process in which the enzyme Rubisco fixes oxygen instead of carbon dioxide (in the first step of the Calvin cycle) Due to Rubisco’s lack of specificity (it

can use O2 or CO2 as a substrate) Happens when stomates are closed(high O2 concentration and low CO2

concentration) Wasteful – uses ATP and NADPH from

light rxns, but makes no sugar!

Photosynthesis: Challenges & Adaptations

Goals for Today: Describe photorespiration and explain why it’s

bad for plants Explain how C4 and CAM photosynthesis get

around the challenge of photorespiration In Groups of 3:

Use a textbook to figure out how C4 or CAM works to circumvent photorespiration

Answer the questions on your assigned page Every member of your group should be

ready to explain this to the class!

AP Bio: Tuesday, 11.30.10Photosynthesis: Challenges & Adaptations

Homework: Lab 4 Pre-Lab (read procedure and answer pre-lab questions)

Do Now: (in your mind or your notebook) What photosynthesis adaptation did your group study? Both of these adaptations separate the initial step of carbon

fixation from the actual Calvin cycle. Does your adaptation separate these things temporally or spatially?

Goals for Today: Explain how C4 and CAM photosynthesis get around the

challenge of photorespiration Agenda:

C4 and CAM presentations Pre-Lab for Lab 4

AP Bio: Wednesday, 12.1.10Lab 4: Rates of Photosynthesis

Homework: Lab 4 Graph and Analysis Questions

Do Now: Take out Lab 4

Goals for Today: Predict and measure how _____ and __________ affect

rates of photosynthesis Explain how our experimental setup allows us to do

this Agenda:

Review Pre-Lab and experiment set-up Set up chloroplast suspension Do the lab!

Lab Groups for Today:

Set up tubes now and come back 3rd or 4th period: Gina Shannon Elaine

Sayed Yanira Alex

Surendra

Wilmene

Sohaila

Wilanda

Tracy Leo

Elias Hanna

h Eliza

Betsie Juliana

Peter Ned

John Camer

on Maria

AP Bio: Thursday, 12.2.10Cell Energetics Wrap-Up & Review

Homework: Study for Test on Cell Respiration & Photosynthesis

Do Now: Sit with your lab group from yesterday (but at the

desks and front tables) Take out Lab 4 Volunteers draw graphs on the board

Goals for Today: Explain the results of the photosynthesis lab Compare and contrast cell respiration and

photosynthesis Review Cell Energetics by playing Jeopardy!

Compare/Contrast CR and P-sis

In your notes, with your lab group:

Make a list or table in which you brainstorm all the similarities and differences between photosynthesis and cellular respiration Include:▪ Broad Concepts▪ Specific Details

AP Bio: Monday, 12.6.10Test on Cellular Energetics

Homework: Chapter 35 Reading Notes

Do Now: Look over PS 10 Get ready for the test

Goals for Today: Demonstrate knowledge of cell respiration and

photosynthesis by answering AP-style multiple choice and open response questions

Agenda: Quick review of PS 10 Test