My first ever youtube video… Here is a link to access your school email. If you have forgotten your email password then ask someone who can access their email to contact Genessa Waite at waite_g@4j.lane.edu so she can update your password to the standard one we use at Cal Young. I can also help with that if you want to email me at hohenemser@4j.lane.edu. I’m looking forward to getting back in touch with more of you. Thank you to those of you who have reached out to me already.
You will be able to use your Big White Sheet on the quiz.
You will be asked to apply your knowledge of the reactants and products and energy transformations that take place during cellular respiration to a new situation.
Big Ideas:
Cell Respiration is a chemical reaction that takes place in plant and animal cells all the time 24/7. Even in the dark for plants or while humans and animals are resting all cells require energy to survive. The energy required comes from the breakdown of glucose which stores chemical energy in its bonds. When glucose that we eat or plants make reacts with oxygen a chemical reaction takes place that produces water and carbon dioxide as products. This chemical energy can be converted to kinetic/thermal energy.
In class, we collected evidence for each molecule in the chemical reaction called cellular respiration (except water) using data from plant experiments or data provided in the science notebook for humans and animals. The big idea is that if a molecule is a reactant we should see the amounts decrease as the molecules break apart and rearrange during the chemical reaction. If a molecule is a product of cell respiration (or any chemical reaction) we will see the amount increase as it is produced
Photosynthesis is a chemical reaction requiring light energy that allows plants to make their own food
All of the food we eat originates with plants
The reactants in the chemical reaction photosynthesis are Water (H2O) and Carbon Dioxide (CO2).
The evidence that Water (H2O) is needed for plants to grow and make food comes from our wheatgrass experiments. The seeds that were not watered did not grow at all whereas the seeds that did get watered grew well.
The evidence that Carbon Dioxide (CO2) is a reactant in photosynthesis comes from our experiment with Bromothymol Blue or BTB an indicator for pH. BTB turns yellow in the presence of lots of CO2 and when the BTB turns blue it means the CO2 levels are low. When we left two test tubes with yellow (High CO2) BTB overnight the one with the elodea plant in it changed to dark blue and the control test tube without a plant remained yellow. The blue color indicated that the plant used up the CO2.
The products in Photosynthesis are Glucose and Oxygen
The evidence that Glucose is produced during photosynthesis is that the geranium leaves that were covered with aluminum foil did not show much or any evidence of starch being present. (plants turn the glucose into starch for storage and it is easier to test for the starch than the glucose). This was indicated by the color of the leaf not changing to dark blue when we added iodine, whereas the plant left in the light turned dark blue in the presence of iodine indicating the presence of starch. This also provided evidence that plants need light to do photosynthesis.
The evidence that Oxygen is produced during photosynthesis comes from the elodea plants kept under the light. We observed bubbles in the beaker with the aquatic plant elodea. We measured that water with a dissolved oxygen concentration (mg/L) probe and determined that the beaker with the plant had higher levels of dissolved oxygen than the beaker with water and no plant. This is evidence that the plant must be producing oxygen.
The chemical equation for photosynthesis is carbon dioxide+ water –> glucose and oxygen
When we built the molecules for the chemical reaction we realized that we need 6 H2O molecules and 6 CO2 molecules to make one glucose molecule, so the way to write the chemical reaction more accurately would be 6H2O + 6 CO2 –> Glucose + 6O2. If you count all the atoms on the reactant side(the left) they are equal to all the atoms on the product side so that the equation supports the scientific principle of conservation of mass/matter.
The energy conversion that takes place in photosynthesis is light energy (LE) gets converted into chemical energy (CE) that is stored in the food molecules in the plant.
Evidence of Starch in geranium leaf left in light
Evidence of Oxygen bubbles in elodea plant left in the light
Evidence that elodea used the CO2 in the BTB when left in the light
Evidence that wheatgrass seeds need water to sprout and grow
Balanced Chemical Reaction for Photosynthesis. Mass is conserved!
You should be able to recognize images of starch molecules and protein molecules as well as their subunits (see links above) Remember that if nitrogen (blue) is part of the molecule then it has to be a protein or an amino acid.
Lesson 5: You should know that the rat study was important because it provided evidence that the protein we eat is used to replace old proteins in our bodies and that not all of it is excreted as previously thought.
You should know that animals store extra food as fat. If animals eat more calories than they expend they will store all food molecules as fat (and glycogen.. but we don’t really get into that in this lesson)
hydrolysis and dehydration synthesis
Lesson 4: Hydrolysis (hydro: water lysis: cut, separate) is the chemical reaction that breaks down big food (proteins and large carbohydrates like starch) molecules into small molecules (amino acids and glucose/sugars) during digestion so that the molecules can enter the body’s cells and be used for energy, building materials, and repair. water and big food molecules are the reactants in this chemical reaction and subunits are the product. You tasted this chemical reaction at work while you were chewing a cracker in class and it started to taste sweet.
Lesson 5: Dehydration Synthesis: (dehydration: remove water synthesis: put together) is a chemical reaction that builds up big molecules by removing HO and H (H2O) from the subunit amino acids to make proteins that are used by the body. (This chemical reaction also takes place in plants to build large starch molecules. we will cover this in lesson 6)Subunits like glucose and amino acids are the reactants in this chemical reaction and water and large molecules are is a product in this chemical reaction. This is what we modeled with the paper in class on 11.1.19.
Food (carbohydrates, proteins, and fats) has the capacity to provide the body with energy and building materials.
Food molecules react with oxygen to provide energy to the cells of the body.
Food molecules are similar in that they are all made of C, H, and O; and for proteins and carbohydrates, many subunits join together to form complex molecules.
Fat molecules provide the body with more energy than carbohydrate and protein molecules because of their type, number, and arrangement of atoms.
You have to exercise longer or harder to expend the energy that can be provided by fat than for the same mass of carbohydrates and proteins.
If you think it might help with your comprehension and focus when doing science homework, the readings in all of our science notebooks are available through the
IQWST student Portal: Use your 4j username and 6 digit student ID as the password to access read aloud through the portal. Then navigate to your current SN and tap in the upper left corner to select the reading number. I recommend that you read along in your science notebook so you can pause the recording and mark the text as well as answer the questions as you get to them.
Recently students were asked to take C-notes on IC3 reading 2.1 (pages 34-47). Students were asked to mark the text by circling key words and underlining the main ideas. They were also asked to add 4 margin notes for each of the paragraphs labeled, Conditions, Variables, Sample Size and Collecting Data. After this was complete it was time to start the C-notes. Here are some step by step instructions to C-notes. (Here is a link to the set of C-notes I wrote as an example)
1. Fill out the heading on the c-note paper provided and write the essential question which was provided by the teacher. EQ: What are the components and steps to designing an effective scientific investigation?
2. Write Notes: Write notes about the 2 + pages of reading in the notes section on the C-note paper. Try to chunk your notes with headings and some organizational system and leave some spaces in case you need to add more information later. (use both sides of the paper)
3. Interacting with your Notes: Look back through your notes (we did this the next day) and circle keywords and underline main ideas in your notes. You can also write more details that you think should be added and cross out unnecessary information. Add a diagram or two if that would help with your learning
4. Questions: For each underlined main idea, you should now write a question across from it in the left-hand column labeled questions. The questions should be answered by the notes on the right. You should be able to use this as a study guide, asking yourself the questions on the left and checking the answers on the right.
5. Summary: Time for the summary. The introductory sentence can be a generic answer to the essential question (EQ). Think of it as reframing the EQ as a statement rather than a question. For each of the rest of the sentences in your summary consult your questions and answer them in your own words. This should create an excellent summary that includes all the important details. If you run out of space, feel free to add a piece of paper to your notes.
6. Study your notes: Use your notes to study for the quiz on Experimental Design on Tuesday, October 8th! You may find that after all this REPITITION you already know the material pretty well. There is also a Quizlet to study and your SN lesson 2!
