Lab Data for G block

On Monday, each student will need to turn in the following information:

1. A table with the class averages for Hot, Cold and Room Temperature bubble height in cm (from part A)

2. A table with the class average for Acid, Base and Neutral bubble height in cm (from part B).

3. A well written paragraph, with complete sentences, which includes three sources of error for the experiment and three ways to improve the experiment.

If you are unsure about what to include for your sources of error you can read this article.

Below is the data for you to analyze. You can click on the picture to make it larger.

Enzymes

What do they do? Where are they found? Today we learned about how enzymes work. Later this week we will be doing our first QUANTITATIVE lab and as such, spent a bit of time today going over the procedure.

Homework:

Read the "Potato Catalase Lab" post below. In your lab notebooks, finish writing part B of the procedure and answer the prelab questions. This is due for your next lab period.

Potato Catalase lab

Investigating the Effects of pH and Temperature on Enzyme Activity

Background: In this lab exercise we’ll investigate some of the properties of enzymes. Almost all chemical reactions that occur in living things are catalyzed by enzymes. Enzymes are large protein molecules (macromolecules) that catalyze or speed up chemical reactions without being altered themselves. Proteins can be just about any size or shape, which is useful since it’s the shape of an enzyme that determines the reactions it can catalyze. However, enzymes are sensitive to changes in temperature and pH, which alter their shapes and can even destroy catalytic ability (denaturing). Enzymes have evolved to work most efficiently at the temperature and pH found in the part of the organism where they are needed. Many enzymes in the human body function most efficiently at 37^oC and at a pH of 7.4.

The enzyme you will investigate is called catalase. Catalase is found in tissues of many organisms (both plants and animals) because it plays a very important role in protecting cells. Its purpose is to destroy toxic substances which may be introduced into cells. Also, some cells use catalase to destroy cellular debris or worn out organelles. Hydrogen peroxide is a normal by-product of cellular metabolism but, it is also toxic to cells. Under normal conditions organisms produce the enzyme catalase that quickly changes hydrogen peroxide into two harmless substances, oxygen and water. However, the function of the enzyme is affected by changes in the environment. Catalase works to break down hydrogen peroxide by the following chemical reaction:

2 H₂O₂ ------------------>2 H₂O+ O₂

(Catalase)

Purpose: What is the effect of altering the pH on the function of catalase?

Pre Lab Questions (ANSWER IN COMPLETE SENTENCES IN YOUR LAB NOTEBOOK. This answers should be directly below the procedure that you worked on in class).

1. What is catalase and where is it found in living organisms?
2. What reaction does catalase speed up (catalyze)?
3. Write the correct chemical reaction for hydrogen peroxide being catalysed into water and oxygen.
4. What is the substrate in the chemical reaction?
5. What are the products in the chemical reaction when catalase breaks down hydrogen peroxide?
6. Write hypotheses for how you think changes in pH AND temperature will affect the action of the catalase enzyme in the potato.
Hypothesis for change in pH.
Hypothesis for change in temperature:

Materials:

• 0.1 M HCl (hydrochloric acid)
• 0.1 M NaOH (sodium hydroxide)
• 6 large test tubes
• test tube rack
• hot water bath
• ice bath
• 10ml graduated cylinder
• 100ml beaker
• Transfer pipet
• 3.0% H₂O₂ (Hydrogen Peroxide)
• test tube holders (for hot water bath)
• Safety glasses
• Potatoes
• Ruler

Safety: HCl and NaOH are strong acids and bases. If you spill these chemicals on your skin, immediately wash in running water. Wear safety glasses at all times. Be careful of hot water and hot plates.

Part A:

1. Label 3 large test tubes hot, cold and room temp.
2. Cut 3 1.5cm³ pieces of potato with peel removed.
3. Use a mortar and pestle to macerate (mash/grind up) each cube.
4. Place ALL of the macerated potato cubes into each labeled test tube.
5. Add 1ml of distilled water to each test tube containing potato mash.
6. Place the test tube labeled hot in the hot water (100^oC) bath for 3 minutes.
7. Place the test tube labeled cold in the cold water bath (0-4^oC) for 3 minutes.
8. Leave the test tube labeled room temperature in the test tube rack.
9. After 3 minutes, remove the test tube from the baths and allow the hot test tube to cool.
10. Add 5ml of H₂O₂ (3.0% hydrogen peroxide) to each tube.
11. Wait one minute while reaction occurs then measure the height of the bubbles in each tube in cm.
12. Record in Table 1. Measure the radius of the test tube and record in Table 1.

Part B:

1. Label 3 test tubes acid, base and water.
2. Cut 3 1.5cm³ pieces of potato with peel removed.
3. Use a mortar and pestle to macerate (mash/grind up) each cube.
4. Place ALL of the macerated potato cubes into each labeled test tube.
5. Add 1ml of 0.1M HCl (hydrochloric acid) to the tube labeled acid. Gently mix contents with wooden or glass rods. SEE SAFETY NOTE ABOVE.
6. Test the pH of the solution by dropping a small amount of liquid onto a pH strip. Record in Data Table 2.
7. Add 1ml of 0.1M NaOH (sodium hydroxide) to the tube labeled base. Gently mix contents with wooden or glass rod. SEE SAFETY NOTE ABOVE.
8. Test the pH of the solution by dropping a small amount of liquid onto a pH strip. Record in Data Table 2.
9. Add 1ml of water to the tube labeled water. Mix contents by gently swirling. Test the pH of the solution by dropping a small amount of liquid onto a pH strip. Record in Data Table 2.
10. Wait 3 minutes then add 5ml of 3%H₂O₂ to each tube.
11. Wait 1 minute for reaction to occur, then measure and record the height of the bubbles in cm.
12. Record in Table 2. Measure the radius of the test tube and record in Table 2.

This lab is borrowed from EDCC

Quiz Monday

This is a reminder that you have a quiz on Monday. Sections 2.1-2.3 (pages 35-48). You can NOT use any notes.

Macromolecules

Today students had a reading quiz on section 2-3. After going over the quiz students were given a worksheet on the types of Macromolecules. We didn't get a chance to talk about food pyramids around the world, but hopefully we will get a chance with Thursday's classes.

Homework: Review the PowerPoint below with the information about the lab for Friday. Before coming to class on Friday you should fill the in the table of contents in the lab section of your notebook with the following information:

Date: 24 September
Title: What's in your food?
Partner: (leave blank for now)
Page: 5

On page 5 in your notebook (a sheet of notebook paper) copy down the table from the slide titled "Background Information" (this is slide number 6).


A note about testing for lipids: We may not have Sudan IV solution, so we may be doing the less glamorous "paper towel test."

Please also bring a food you would like to test.

Lab Procedure

Identifying Macromolecules In Food

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pH and intro to carbon

We started class today with a reading quiz on 2-2. Students then did a quick lab activity where they needed to determine the pH of eight unknown substances.

The last 15 minutes of class were spent starting section 2-3. Students were given a guided notes sheet.
Homework for tonight: (due the next time your class meets) Read the rest of section 2-3 and take notes. YOU WILL HAVE A READING QUIZ.

On Friday a summary report (1 per group) is due. The summary report can be any of the following:

Make a Venn diagram and fill in the names or draw pictures of the items that were in each of the solutions in the correct section in the diagram and write the properties in the correct section. (See example below.)

Write a brief report about acids, bases, and neutrals in paragraph form and include examples from the testing lab.

Draw a concept map or word web comparing and contrasting acids and bases and add descriptive words and examples. (See example below.)

Create a narrative poem, song, or story about the acid, base and neutral solutions and describe their properties.

Your summary report must also include the answers to the following questions:
1. What is the pH of human blood?
2. What is the pH of stomach acid?
3. What are antacids and how do they work?

Bonus point opportunity: If you find the actual pH's of all 8 substances, you can earn a bonus on your summary report.

Reviewing Tests & Starting Chapter 2

Today we spent about 20 minutes reviewing the first test of the year. Afterwards we moved on to chapter 2: The Nature of Matter.

From now on I will do my best to have guided notes sheets for students to use in class. Hopefully this will help students to have more organized notes and enable them to study more effectively.

We watched this clip comparing ionic and covalent bonding.

We also watched a clip from the Discovery channel on Kennewick Man and the role that radioactive carbon dating played in discovering the age of this mysterious man.

Homework: Read section 2-2 (pages 40-43). Take notes that include the key concepts and vocabulary. You will have a reading quiz tomorrow.

Test Today & Grade Weighting Update

Today students had a test on Chapter 1. Next week we will be moving on to the basic chemistry for biology.

There has also been a change in the weighting of assignments. Tests are now worth 20% (instead of 30%) and classwork/participation is worth 10%.

H1N1 discussion

Yesterday and today students discussed the articles they found on H1N1. Students worked in small groups to present their articles and practice active note taking. After each group member shared, the class came together to share key points from the discussion groups. There were several terms (such as pandemic, epidemic, immunization and virus) that were mentioned in most articles. To help explain these concepts students watched animations and video clips to further their understanding.

Click here to see the video from Discovery Science to see just how far germs from a cough can travel.

Click here to see the animation from UK NHS on the importance of immunization as a way to stop the spread of disease.

Click here to see the life cycle of a virus from the Howard Hughes Medical Institute.

Below is the video clip we watched to explain the difference between a pandemic and an epidemic.


REMEMBER, YOU HAVE A TEST ON FRIDAY. SEE THE TOP SIDEBAR FOR DETAILS.

H1N1 Homework

Today in class we did the onion & cheek cell lab (see post below). For your next class period (G block is due Wednesday September 16th, F and D blocks this assignment is due Thursday September 17th), complete the following. Your assignment may either be typed or handwritten, however you may NOT email it to me.

1. Find an article on H1N1 (swine flu).
Places to look for articles include: Science Daily, TIME magazine, International Herald Tribune, and the BBC

2. Read it.

3. Write a summary IN YOUR OWN WORDS on the article.

4. Include a proper MLA citation for your article.
To cite a website write down the following information:

Author last name, author first name. "Title of the article." Name of the website. Year the article was published. Name of the organization. Date you read the article. The url for the website.

5. Be prepared to present your article to the class.

EXAMPLE FOR WHAT YOU NEED TO TURN IN.

Ms. Saxe
-- Period
15 September

Summary for

Swine Flu: To Panic Or Not -- That Is The Question

In an effort to clear up all the misinformation surrounding H1N1, Dr. Sutker, of Baylor University Medical Center, gave five overarching facts about swine flu. These facts included that swine flu IS treatable with Tamiflu and Relenza which one can get with a prescription. So far only 40 individuals in the U.S. have been diagnosed with swine flu, compared with 5-20% of the population that contracts influenza A/B each year. Lastly, "you can not get swine flu from eating pork products." In the second part of the article Dr. Sutker offered tips to prevent the spread of infection. These tips, such as frequent hand washing, covering your cough and seeing a doctor if you think you are infected, apply not only to swine flu but for all infectious diseases. Hopefully this information will clear up much of the panic about H1N1.

Citation: Baylor Health Care System. "Swine Flu: To Panic Or Not -- That Is The Question." ScienceDaily 30 April 2009. 15 September 2009 /releases/2009/04/090429144956.htm>.

Lab 1: Making Wet Mount Slides

You are to read the following procedure for homework today (Monday September 14). You will have a prelab quiz. You may use any notes you take HOWEVER, the notes must be in your handwriting. You do not need to print a copy of the lab.

Today we will make slides of 2 different types cells and look at them under the microscope:

1. Onion skin cells
2. Human cheek cells

Onion skin cells

1. Add 2 drops of iodine to the center of a glass slide. Be careful! Iodine can stain your clothes.

2. Take a small piece of onion. Use tweezers to peel off the skin from the underside (the rough, white side) of the onion. Throw the rest of the onion piece away.

3. Carefully lay the onion skin flat in the center of the slide on top of the iodine.

4. Add 2 drops of iodine to the top of the onion skin.

5. Stand a thin glass cover slip on its edge near the onion skin, next to the drop of iodine.

6. Slowly lower the other side of the cover slip until it covers the onion skin completely. If there are air bubbles, gently tap on the glass to “chase” them out.

7. Make sure the lowest power lens (the shortest lens) is in place over the stage and the microscope light is turned on. Place the slide onto the stage of the microscope.

8. Look through the eyepiece and turn the coarse focus knob (the largest knob) until an image comes into focus. It should look like a brick wall or like lizard skin.

9. Now use the fine focus knob (the smallest knob) to make the image as focused as possible.

10. In your lab notebook, draw a picture of what you see. Label the picture “Onion skin cells 40x”. Label as many parts of the cell as you can see.

11. Looking from the SIDE of the microscope, NOT through the eyepiece, rotate the lenses to the next highest powered lens (100x). If you need to, use the fine focus knob (the smallest knob) to get the image into focus. DO NOT USE THE LARGE KNOB!! You may see a small dot in the middle of each cell.

12. Again, looking from the SIDE of the microscope, rotate the lenses to the highest powered lens (400x). If you need to, use the fine focus knob (the smallest knob) to get the image into focus. You should see a dark blob in the middle of each cell.

13. In your lab notebook, draw a picture of what you see. Label the picture “Onion skin cells 400x”. Label as many parts of the cell as you can see.

14. Switch to the lowest power lens and THEN remove the slide. Set it aside for now.

Human Cheek Cells

1. Add one drop of methylene blue to the middle of a clean slide. Be careful! Methylene blue will stain your clothes and skin.

2. Use the flat side of a toothpick to gently scratch the inside of your cheek. DO NOT GOUGE YOUR CHEEK - you don’t need chunks of skin and definitely don’t want to draw blood.

3. Gently touch the toothpick to the drop of dye on the slide. Some of your cheek cells should drift off into the dye.

4. Throw the toothpick away.

5. Stand a thin glass cover slip on its edge near the drop of dye.

6. Slowly lower the other side of the cover slip until it covers the dye completely. Make sure there are no air bubbles.

7. Make sure the lowest power lens (the shortest lens) is in place over the stage. Place the slide onto the stage of the microscope.

8. Look through the eyepiece and turn the coarse focus knob (the largest knob) until an image comes into focus. It should look like scattered blobs. Move the slide around until a nice cluster of blobs moves into the center of your image.

9. Use the fine focus knob (the smallest knob) to make the image as focused as possible.

10. In your lab notebook, draw a picture of what you see. Label the picture “Human cheek cells 40x”. Label as many parts of the cell as you can see.

11. Looking from the SIDE of the microscope, NOT through the eyepiece, rotate the lenses to the 100x lens. If you need to, use the fine focus knob (the smallest knob) to get the image into focus.

12. Again, looking from the SIDE of the microscope, rotate the lenses to the 400x lens. If you need to, use the fine focus knob (the smallest knob) to get the image into focus.

13. In your lab notebook, draw a picture of what you see. Label the picture “Human cheek cells 400x”. Label as many parts of the cell as you can see.

Switch to the lowest power lens and THEN remove the slide.

Introduction to Microscope Work

Today students had an introduction to working with microscopes which included identifying the parts of the microscope, proper techniques and looking at a variety of slides. Students had the opportunity to look at:

Human blood
Human scalp with hair and sweat glands
Human lung
Frog skin
Large intestine from a mammal
Pollen from a Lily
Spirogyra (a freshwater algae)
Gills from a catshark
A cross section of stem from a Basswood tree.

HOMEWORK: READ THE PROCEDURE FOR LAB 1: MAKING WET MOUNT SLIDES (posted above).

You will have a pre-lab quiz on the procedure. You may use any notes that are in your own handwriting. You do NOT need to print a copy of the lab.

Graphing Practice

Today students practiced graphing and interpreting data. We started by interpreting a pie chart and line graph. Students then worked independently to create scatter plots on data.

Graphing Practice Problem

Water Temperature in oC	Number of developing clams
15	75
20	90
25	120
30	140
35	75
40	40
45	15
50	0

1. A clam farmer has been keeping records concerning the water temperature and the number of clams developing from fertilized eggs. The data is recorded above.
2. Make a line graph of the data.
3. What is the dependent variable?
4. What is the independent variable?
5. What is the optimum temperature for clam development?

For the tree problem click here
For the tadpole problem click here

These problems were adapted from the Desert Vista High School in Phoenix, AZ, USA.

There is no homework this weekend.

Controls & Variables

Today students practiced identifying controls and variables using practice problems. We also talked about themes in biology and levels of biological organization.

Homework: Read pages 24-28, take notes which include the key concepts and the vocabulary. Who knows...you might just have a reading quiz....

What is science

Today students identified what is and is not science as well as practiced making observations and hypotheses by working with stick insects.



Homework:
Read section 1-2 (pages 8-14).
Take notes and make sure to include the key concepts and definitions for the vocabulary words. Remember: vocabulary words are highlighted in yellow.

Please bring your text book to class on Thursday.

Welcome!

Hopefully you have overcome your initial confusion as to why you were asked "What sound does a raisin make?" This blog is a place where homework assignments, links and videos to help you learn and reminders about upcoming major assignments will be posted.

Today you received a syllabus and a textbook.

Tonight for HOMEWORK you need to review the syllabus and complete the BOOK TOUR.

Remember: No late homework is accepted. Start the year of right by completing this short assignment.

Below is the PowerPoint from class today. Depending on what we are doing, I may or may not post the PowerPoints here. You are expected to pay attention in class and take good notes!

Opening Day

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