In This Lesson: Unit 3 ATP, Autotrophs, Heterotrophs (Lesson 1 of 3) Today is Wednesday, October 28 th, 2015 Pre-Class: How do cells get their energy? Make a list in your notebook of the different ways you can think of I m calling on each of you today. [ListBuilding Activity] Also, get a SMALL paper towel for your pair.
Today s Agenda Unit 3 Challenge Questions Explore the Trophic Pyramid Distinguish between Autotrophs and Heterotrophs The 10% Rule Cure world hunger Introduce ATP And ADP! Where is this in my book? Academic: P. 201 and following Honors: P. 72 and following
By the end of this lesson You should be able to distinguish between autotrophs and heterotrophs in reference to the trophic pyramid. You should be able to describe ATP s biochemical role in supporting life processes.
Challenge Questions Grab yo whiteboards!
ExploreLearning.com You have another challenge. Visit ExploreLearning.com and run the gizmo called Food Chain. You will see a sample food chain consisting of grass, rabbits, snakes, and hawks. Play around with it for a little bit and explore the options it has. Healthy vs. Diseased Number of animals I will be putting questions on the board shortly. [Log-in Instructions]
Food Chain Gizmo
Food Chain Questions Work with your partner and submit your answers on one sheet of paper when you finish. You DO NOT need to write the questions.
Food Chain Question #1 Thinking in terms of energy (production and consumption), how are grass, rabbits, snakes, and hawks different? If you had to place them into categories based on their differences, what would those categories be named?
Food Chain Question #2 Would it be possible to have more hawks than snakes and the population remain stable? Why or why not?
Food Chain Question #3 Any guesses as to why they show this food chain as a pyramid? How come the top is not as big as the bottom?
The Big Root Word There s one big root word I want us to know for today: TROPH In Greek, troph refers to food or feedingrelated stuff. In biology, well, it s in two slides.
Aside: Trivia Question! What about -vore as in carnivore (meaning meat/flesh-eating )? What do these other terms eat? Herbivore Plants Omnivore Plants/meat Frugavore Fruit Granivore Grains Foliovore Leaves Palynivore Pollen Graminovore Grass Nectivore Nectar Insectivore Spongecake Just kidding insects. Sanguivore Blood Detritivore Detritus (dead and decaying stuff)
Autotrophs and Heterotrophs There are two kinds of living things out there, and they get their energy from different sources: Autotrophs Photosynthesis/Respiration Heterotrophs Respiration Autotrophs Heterotrophs Trophic Levels
Autotrophs and Heterotrophs Autotroph An organism capable of making its own energy. Typically needs the sun. Plants are the classic example. Heterotroph An organism not capable of making its own food. Must eat an autotroph or another heterotroph to obtain energy. Animals and fungi are the best examples. Fun Fact: There are some organisms capable of photosynthesis that do eat other living things. They re called mixotrophs.
So why s it a pyramid? There s also this thing called The 10% Rule. And to explain it, we ll need some vocabulary
The 10% Rule See the 1000 Kg written on the bottom row? That s the biomass of that level of the pyramid. Biomass = The amount of energy contained in a certain mass of organic matter (technically mass, thought of as energy). http://web1.stmaryssenh.schools.nsw.edu.au/smshs/ricks%20sites/biology%20web%20site/pre_8_2_a%20local%20ecosystem/pyramids/biomass-uprightpyramid.jpeg.jpg
The 10% Rule Now what about the biomass of the Herbivores level? What fraction of the first level is it? 10% http://web1.stmaryssenh.schools.nsw.edu.au/smshs/ricks%20sites/biology%20web%20site/pre_8_2_a%20local%20ecosystem/pyramids/biomass-uprightpyramid.jpeg.jpg
The 10% Rule Now look at the rest of the levels. Same 10% relationship! http://web1.stmaryssenh.schools.nsw.edu.au/smshs/ricks%20sites/biology%20web%20site/pre_8_2_a%20local%20ecosystem/pyramids/biomass-uprightpyramid.jpeg.jpg
So what gives? The 10% Rule states that only 10% (average) of the biomass at any given trophic level is available to the organisms on the level above. And in English? Let s say that the energy available in the grass level (autotrophs) is 100 energy units. The rabbits (heterotrophs) can only gain a maximum of 10 energy units. So will there be more grass or rabbits in this relationship?
The 10% Rule This is why it s a trophic pyramid because the levels can support fewer and fewer organisms as they go up because there s less and less energy available. Decomposers help return some of the energy gained by all levels to the bottom level. Now the question is, what form is that energy in? Ended in a preposition
http://savingmoneyplan.com/wp-content/uploads/2012/11/hersheys.jpg ATP What I d like you to think about when you hear ATP is a giant chocolate bar: ATP
Chocolate Chocolate is high in Calories. Therefore it s got a lot of energy. Chocolate is high in sugar. It provides you with a boost when you eat it. Chocolate bars often are divided into squares or rectangles that you can eat one-at-a-time. You don t need to destroy the whole bar to get something out of it.
ATP ATP is an organic molecule with high-energy bonds. When your cell breaks off a part, it replaces those bonds with lower-energy bonds. The cell gains energy. Like breaking off a square of the chocolate bar. ATP can be reused. Like putting a square back on the chocolate bar.
Can chocolate be re-used?
ATP Cells use energy in the form of ATP. It s a way for them to store, transfer, and gain energy. This energy is used for cellular chores, like active transport. Remember that? ATP stands for Adenosine Triphosphate. There are three phosphate groups attached to it. It s higher energy.
ATP ATP is a nucleotide: Nucleotide Adenosine Triphosphate http://www.bio.miami.edu/~cmallery/150/metab/sf6x1a.jpg https://www.msu.edu/course/isb/202/ebertmay/2004/drivers/nucleotide.jpg
ATP
ATP When ATP is used, the cell breaks off a phosphate group to make ADP. ADP stands for Adenosine Diphosphate. It has two phosphate groups. The used up version of ATP. It s lower energy. Key Note: To actually get the energy from ATP, the bond holding the last phosphate group must be broken and replaced with water.
How ATP Works Here s the short story as to how ATP works: ATP is high energy. Breaking off a phosphate group and making ATP into ADP releases energy that the cell can use. ADP is low energy. Adding a phosphate group and making ADP into ATP uses energy but allows ATP to be re-used. Fun facts: The average cell has 1,000,000,000 ATP molecules at any given time. Those ATP molecules are all used up within two minutes.
What s the reaction look like? ATP is dephosphorylated to ADP: H 2 O + ATP ----> ADP + P i + ENERGY! ADP is phosphorylated to ATP: ADP + P i + ENERGY! ----> H 2 O + ATP This is IMPORTANT! P.S. These are types of hydrolysis and dehydration synthesis, respectively. Remember them?
Practice and Closure Find some room in your notebooks and draw your own diagram that illustrates how ATP works. Here s a suggested start (it s incomplete why?): ATP ADP ENERGY
Closure CrashCourse ATP and Respiration