Unit 4: Photosynthesis
Reading
BJU Biology: Ch. 4 (now read the 'rest' of the chapter - that means all of it!)
AP: OpenStax Biology: Ch. 8 "Photosynthesis"
Topics
Homework
Handouts are posted near the bottom.
Lab options for this Unit
BJU Biology: Ch. 4 (now read the 'rest' of the chapter - that means all of it!)
AP: OpenStax Biology: Ch. 8 "Photosynthesis"
Topics
- Photosystems I and II
- Electron Transport Chain
- Calvin Cycle
- Energy molecules ATP and NADPH
Homework
Handouts are posted near the bottom.
Lab options for this Unit
- Ethanol Biofuels Lab
- Plants in a Bottle: Photosynthesis & Respiration
- Algae Beads lab
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Introduction
At this point in the course, we are beginning to see that every cell is really a complex factory, full of nano-machines, walking motor-proteins, and spinning turbo-generators - and that's what makes Biology and Biotechnology incredibly fascinating.
In our previous Unit, we covered animal cells:
In this Unit, we are talking about plant cells:
In photosynthesis, the plant captures photons of light on chlorophyll, which in turn converts the electromagnetic energy into electrical energy (just like an antenna and amplifier do), and then sends the electricity down the line on a series of protein transport molecules which also function as proton pumps, eventually reaching a rotating, proton-powered turbine called ATP Synthase, which charges-up new ATP energy molecules using a rotating camshaft - just like cellular respiration does. The newly-charged ATP energy molecules then power a complex chemical factory within the leaf - with the ATP functioning just like a battery - wherein the plant manufactures all its starch, cellulose, and other molecules from carbon (C) it obtains from atmospheric CO2. Putting it another way, the plant literally 'builds itself' from the CO2 contained in the atmosphere - using ATP batteries which have been charged by a rotary turbine, which is powered by a stream of protons, which were pumped using electricity, which was obtained from an antenna (chlorophyll molecule), which originally had captured a bit of sunlight. When you stand back and realize the beauty and complex engineering contained within that process, Biology starts to get exciting!
Lab: We will make our own biofuel by fermentation, concentrate it, and run a Stirling Motor with it. This two-session lab is an excellent way to learn about cellular respiration, chemical energy, enzymes, fermentation, lab techniques, and how biofuels are made.
At this point in the course, we are beginning to see that every cell is really a complex factory, full of nano-machines, walking motor-proteins, and spinning turbo-generators - and that's what makes Biology and Biotechnology incredibly fascinating.
In our previous Unit, we covered animal cells:
- Animal cells get their energy and raw-materials by breaking down glucose (blood sugar) in a process called cellular respiration.
- We are also learning in our Biofuels Lab that yeast and certain bacteria - although not in the animal kingdom - also perform step 1 of cellular respiration - leading to fermentation.
In this Unit, we are talking about plant cells:
- Plant cells get their energy and raw materials from sunlight and atmospheric carbon dioxide (CO2) in a process called photosynthesis.
- It's important to note that algae - although not in the plant kingdom - also carries out photosynthesis. The algae in the world's oceans actually produce most of the oxygen (O2) we breathe.
- It's also important to note that plants have mitochondria - in addition to having chloroplasts - and thus they carry-out cellular respiration as well as photosynthesis.
In photosynthesis, the plant captures photons of light on chlorophyll, which in turn converts the electromagnetic energy into electrical energy (just like an antenna and amplifier do), and then sends the electricity down the line on a series of protein transport molecules which also function as proton pumps, eventually reaching a rotating, proton-powered turbine called ATP Synthase, which charges-up new ATP energy molecules using a rotating camshaft - just like cellular respiration does. The newly-charged ATP energy molecules then power a complex chemical factory within the leaf - with the ATP functioning just like a battery - wherein the plant manufactures all its starch, cellulose, and other molecules from carbon (C) it obtains from atmospheric CO2. Putting it another way, the plant literally 'builds itself' from the CO2 contained in the atmosphere - using ATP batteries which have been charged by a rotary turbine, which is powered by a stream of protons, which were pumped using electricity, which was obtained from an antenna (chlorophyll molecule), which originally had captured a bit of sunlight. When you stand back and realize the beauty and complex engineering contained within that process, Biology starts to get exciting!
Lab: We will make our own biofuel by fermentation, concentrate it, and run a Stirling Motor with it. This two-session lab is an excellent way to learn about cellular respiration, chemical energy, enzymes, fermentation, lab techniques, and how biofuels are made.
| Photosynthesis lecture slides |
Video clips below: we will watch and discuss in class
Chapter Review Questions 4.2 & 4.3
'Regular' Bio students: Type your answers to these (19) questions and upload to Canvas. Keep the same numbering system and include the questions, or you will have points deducted.
Note to AP Bio students: You will answer the OpenStax Ch. 8 end-of-chapter questions instead. These include #1-3 Art Connection questions, #4-15 Review questions, and #16-23 Critical Thinking questions. Some of these are multiple-choice and you can photocopy the page, while others will require typed answers. Keep the same numbering system! Upload to Canvas when finished.
'Regular' Bio students: Type your answers to these (19) questions and upload to Canvas. Keep the same numbering system and include the questions, or you will have points deducted.
Note to AP Bio students: You will answer the OpenStax Ch. 8 end-of-chapter questions instead. These include #1-3 Art Connection questions, #4-15 Review questions, and #16-23 Critical Thinking questions. Some of these are multiple-choice and you can photocopy the page, while others will require typed answers. Keep the same numbering system! Upload to Canvas when finished.
Photosynthesis questions
Enter your answers directly in Canvas
Enter your answers directly in Canvas
| 6._photosynthesis_questions_2022.docx |
Ethanol Biofuels lab
Below: student example videos on how to make "alternative fuels"
Below: student example videos on how to make "alternative fuels"
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| 5._ethanol_biofuel_lab_handout.docx |
| 5._ethanol_biofuel_lecture_notes.docx |
| 5._ethanol_biofuel_lab_report_instructions_2022.docx |
| 5._biofuels_video_project.docx |
In this lab, we will make ethanol using fermentation, concentrate it using distillation, and demonstrate its capability as a fuel by running a Sterling Engine. This project is an excellent platform for learning about 1) cellular respiration and 2) modern biotechnology.
Learning objectives:
- (optional if time allows) Break-down carbohydrates into sugars using amylase enzyme. This is called "conversion".
- (optional if time allows) Detect sugars and carbohydrates using the Benedicts Reagent test and the Iodine test.
- Fermentation of sucrose to ethanol
- Prove that fermentation produces CO2 as a waste byproduct. Bubble CO2 off-gas through lime water to create Calcium Carbonate precipitate, and observe the accompanying pH reduction.
- Concentrate the ethanol from 10% up to 90%+ using distillation
- Use the ethanol biofuel to run a Sterling Engine
Learning objectives:
- Fermentation is an anaerobic (without oxygen) process which converts glucose into energy for the cells.
- Yeast (and your muscle cells) can use fermentation to generate energy quickly in the absence of oxygen.
- Fermentation represents only the first stage of Respiration. Your body's cells will normally go further to Kreb's Cycle and to Oxidative Phosphorylation - yielding much more energy.
- Fermentation starts with Glucose (6-carbon molecule) and ends at Pyruvate (3-carbon molecule). Complete cellular respiration, by comparison, converts the Glucose (6-carbons) all the way to Carbon Dioxide and water.