Lab 5 – Diffusion, Osmosis and Enzymes

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Lab 5 – Diffusion, Osmosis and Enzymes

Objective: The objective of this lab is to introduce you to the concepts of diffusion, osmosis and enzyme activity.

Reading Assignment: Read 4.9 and 5.4; Diffusion and Osmosis and How Enzymes Work from the textbook Essentials of the Living World.

 

For this lab you will need to supply the following materials:

Camera or cell phone (you will upload pictures of your experiment)

Kitchen scale (food scale, it can weigh in either ounces or grams)

Microwave

Liquid measuring cup

Teaspoon

Tablespoon (3 Tsp = 1 Tbs)

Several Drinking cups (1 needs to hold at least 2 cups of liquid)

1 Potato

Knife

Blender or Potato masher

Zip lock sandwich bag (not a freezer bag)

Pancake syrup

Salt

Sugar

Vinegar

Hydrogen Peroxide (H2O2)

 

Solutions to prepare

Sucrose solution – add one tablespoon of sugar to 1 cup of water

 

Exercise 1 – Diffusion

· In this exercise you will observe the diffusion of water through a semipermeable membrane (a plastic bag)

Step 1. Place ÂĽ of a cup of pancake syrup into a plastic zip lock bag and seal the bag.

Step 2. Weigh the bag using a small kitchen scale and record the weight on your worksheet.

Step 3. Fill larger cup (2 cup measuring or equivalent) with 1 cup of water. Record the time.

Step 4. Place the syrup bag in the larger cup and leave overnight (12+ hours).

Step 5. Remove the bag, dry it off and weigh it using a small kitchen scale. Record weight on your worksheet and the time you ended the experiment. (Hint: The bag should gain weight. If it loses weight you may have had a puncture. You must redo this exercise).

Step 6. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name and a photo ID.

Exercise 2 – Osmosis

· In this exercise you will determine the result of putting cells into solutions of various tonicity.

Step 1. Cut (2) potato slices: 3 inches long, 1 inch wide, 0.5 inches thick.

Step 2. Prepare two coffee cups with the following solutions:

Cup 1 = add one cup of water

Cup 2 = add one cup of water and 1 teaspoon of salt

Step 3. Add one potato slice to each cup and let stand for 1 hour.

Step 4. Remove potato slices and determine if the slice is crisp or limp. Record your observations of the slices on the data sheet.

Step 5. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name, and a photo ID.

Exercise 3 – Enzyme Activity

· In this exercise you will observe factors that affect the enzyme activity of catalase. Catalase is found in potato cells.

H2O2 (hydrogen peroxide) 2 H2O + O2 (oxygen gas) when catalase is present.

Step 1. Place the remaining amount of potato in a blender with two tablespoons of water. Blend to a paste. If you don’t have a blender use a potato masher to make the paste.

Experiment 3-1

Step 2. Transfer one tablespoon of the paste to a small cup and add 1 tablespoon of hydrogen peroxide.

Step 3. Mix together by gently rotating the cup clockwise and record your observations on the data sheet

Step 4. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name and photo/student ID.

 

Experiment 3-2

Step 5. Transfer one tablespoon of the paste to a small cup and add 1 tablespoon of sucrose solution.

Step 6. Mix together by gently rotating the cup clockwise and record your observations on the data sheet.

Step 7. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name and photo/student ID.

 

Experiment 3-3

Step 8. Transfer one tablespoon of the paste to a small cup and add 1 tablespoon of vinegar (an acid).

Step 9. Next add 1 tablespoon of hydrogen peroxide.

Step 10. Mix together by gently rotating the cup clockwise and record your observations on the data sheet.

Step 11. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name and photo/student ID.

 

Experiment 3-4

Step 12. Transfer one tablespoon of the paste to a small cup and add 1 tablespoon of water.

Step 13. Microwave on high for 1 minute.

Step 14. Remove from microwave (careful it’s hot) and allow 5 minutes to cool.

Step 15. Next add 1 tablespoon of hydrogen peroxide.

Step 16. Mix together by gently rotating the cup clockwise and record your observations on the data sheet.

Step 17. Take a picture of the completed exercise and upload to the worksheet. Make sure it includes the date, your name and photo/student ID.

 
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Biology Essay Help

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Complete 6 out of 8 questions in this Essay Section, required questions are: 1, 2, 3, 4, and 7. Alternate questions are 5a or 5b and 6a or 6b. Select one of each of these questions to answer

1. You scoop up a water sample from a local pond nearby, because you are curious about the possible microbes that might live there. After looking at several slides that held drops of the sample, you noticed two different kinds of cells: One kind was very small and had no separate internal structures; the other kind was much larger, and it contained several kinds of internal structures that were physically different from each other. Please name each cell and briefly describe their overall similarities and differences.

2. PKU (phenylketonuria) is an enzyme deficiency disease that only develops in individuals who are homozygous recessive for that gene. An individual with PKU has parents that do not have this disease. What is the parents’ genotype for the gene responsible for PKU? What is the probability that they may have another child with PKU? How many future children of the affected individual will be carriers? Explain your answers.

3. Humans share 99% of their genes with chimpanzees, 90% with mice, 50% with fruit flies, and 37% with celery. Please explain the evolutionary significance of these data.

4. Describe the major land biome where you live. How have human activities changed the landscape and how has this affected native species? Include specific examples.

5. The habitat of one species of tropical fish is red coral reefs. The large majority of the fish in this population are red. A few individual fish carry a mutation that prevents the production of the red pigment; as a result these individual fish are white. The temperature of the ocean where these fish live gets warmer and warmer over a 10 year period, and as a result the coral is bleached and turns white. Use what you have learned about natural selection to explain how this bleaching event may have affected the evolution this fish population (not including possible direct effects of warmer temperatures on the fish). Include the following terms in your explanation: differential reproduction, beneficial trait, allele frequency, selection pressure, evolution.

Alternative to question 5:

At the beginning of the spring, Dr. Betty Burner notices that there is an equal distribution of long and short stemmed the dandelions in her backyard. By the end of the summer she notices that the majority of the dandelions have short stems. This observation is an example of what biological principle? Develop a hypothesis as to why there was an increase in the proportion of the short stemmed dandelions within the population.

6. You have read that inorganic fertilizers contribute to water pollution and would like to make a switch from inorganic fertilizers to organic compost in your vegetable garden. A friend graciously gives you a truck load of his compost. As a good researcher and critical thinker you are not convinced that organic compost will yield the same results as the inorganic fertilizer you have used for years with good results. To draw your own conclusion based on scientific evidence you decide to conduct an experiment in your garden. State a good hypothesis, design an experiment (include test subjects, sample size, control(s), dependent and independent variables, type of data collected) and hypothetical results/conclusion. Does your conclusion support the hypothesis?

Alternative to question 6:

If researchers establish that Myrothecium verrucaria is an effective biological control agent against kudzu, they must then demonstrate that the pathogen will not harm desirable species such as soybeans (a close relative to kudzu). Describe an experiment that could fulfill this purpose, including all steps of the scientific method. Identify control(s), dependent and independent variables.

7. Use what you have learned about energy transfer in food chains and the second law of thermodynamics to explain why it is an environmentally good choice to eat a plant based diet. Include the following terms in your answer: producer, herbivore, omnivore, trophic level, resources and energy

 
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Evidence For The Theory Of Evolution

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1. Evidence for the theory of evolution includes all but __________ (Points : 5)
the fossil record.
biochemical similarities among all living things.
catastrophism.
biogeography.

2. Chelonia mydas is the scientific name for the green turtle. Chelonia is the __________ (Points : 5)
genus.
species.
order.
domain.

3. Characteristics of prokaryotes include all of the following EXCEPT FOR: (Points : 5)
a single, circular chromosome
most commonly reproduce by asexual fission
having membrane enclosed organelles
small in size and can only be seen with a microscope

4. Protists ____________. (Points : 5)
are prokaryotic cells.
have a nucleus.
are most closely related to animals.
live in dry environments.

5. Viruses are __________ (Points : 5)
prokaryotic cells.
eukaryotic cells.
non-living particles.
large in size.

6. Angiosperms produce all of the following EXCEPT __________ (Points : 5)
flowers.
fruit.
pollen.
cones.

7. An organism is multicellular, has cell walls made of chitin, and absorbs its food. In which Kingdom does it belong? (Points : 5)
Animalia
Fungi
Plantae
Protista

8. Dissolved sugar is carried throughout the plant in which tissue? (Points : 5)
cortex
xylem
cambium
phloem

9. Characteristics of animals include all of the following EXCEPT FOR: (Points : 5)
multicellular
unwalled cells
capable of photosynthesis
have the ability to reproduce sexually

10. Which of the following statements is TRUE? (Points : 5)
Mammals are invertebrates.
Invertebrates have a backbone.
There are more species of invertebrates than vertebrates.
Arthropods are the least abundant species.

11. Where is bile produced? (Points : 5)
the gall bladder
the pancreas
the liver
the small intestine

12. The sites of gas exchange in the lungs are the ____. (Points : 5)
bronchioles
alveoli
bronchi
integument

13. The functional units inside of kidneys are the ____. (Points : 5)
sarcomeres
ureters
malpighian tubules
nephrons

14. ___ tissue allows a body to detect and respond to internal and external changes. (Points : 5)
Epithelial
Muscle
Connective
Nervous

15. Which blood vessels return the blood to the heart from the lungs? (Points : 5)
pulmonary arteries
pulmonary veins
systemic arteries
systemic veins

16. The relationship between a flowering plant and mycorrhizal fungi is an example of ___. (Points : 5)
commensalism
parasitism
mutualism
predator/prey interaction

17. Currently, the human population is nearing ___. (Points : 5)
275 million
3 billion
7 billion
9 billion

18. Which of the following organisms would be found at the lowest trophic level of a food chain? (Points : 5)
rabbit
hawk
mushroom
oak tree

19. Which of the following is not considered a density-dependent factor? (Points : 5)
An infestation of parasites on a deer population
Competition for nesting sites for bald eagles
Predation of cheetahs on a population of gazelles
A hard freeze on a plant population

20. A keystone species ___ (Points : 5)
nfluences the survival of several other species within a community.
never goes extinct.
has little impact on the ecosystem.
has the largest population in an ecosystem.

 
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Case Studies in Neurology

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ignment Details

Focus on Case Studies in Neurology

For this assignment you will respond to three case studies.

What is a Case Study?

“A case study is a narrative used to help you practice real-life analysis and communication skills. It is a learning tool that provides readers with “enough detail…to understand the nature and scope of the problem, and…serve as a springboard for discussion and learning” (O’Rourke, 2007, p. 391).

Use your textbook and academic resources from the Library to support your responses.

Access the Library directly from Course Resources for this class, or through the student portal. Be sure to cite and reference all your sources. The Library has a feature that allows you to automatically create an APA formatted reference.

Your completed case studies should be between 750–1000 words, and all sources must be properly cited using APA format.

CASE STUDY #1

  1. Amy is cooking dinner for her family. She moves to pull a pot off the stove and accidently touches the burner. She reflexively pulls her finger away from the stove and immediately feels the pain.
    1. Which receptor neuron is responsible for sending information from her finger to her peripheral nervous system?
    2. Is this receptor neuron, an afferent or efferent neuron?
    3. Explain where the information from the receptor neuron is sent and how does it result in Amy moving her finger away from the stove.
    4. Describe the three classes of neurons involved in this response.
    5. Evolutionarily, why do you think the human body has this system in place?
    6. What might happen if we did not have this response?

CASE STUDY #2

  1. Glen, who is 45 years old, begins to notice that his hands shake (tremors) when he is performing everyday tasks such as signing his signature. His family members have noticed that he also has muffled speech and tends to shuffle when he walks. He is diagnosed with Early Onset Parkinson’s disease.
    1. What is Early Onset Parkinson’s disease?
    2. What specific cell type is affected in Parkinson’s disease?
    3. What is dopamine? What effects does dopamine have on the body?
    4. Explain the structure of a synapse and why Glen’s neurologist would prescribe him a dopamine agonist?
    5. Glen has genetic testing performed and it is determined that he does carry an autosomal dominant mutation in the SNCA gene associated with Early Onset Parkinson’s disease. Glen has three children. Would you advise his children to have genetic testing performed to determine if they also carry the disease mutation? Why or why not?

CASE STUDY #3

3. Patricia, who is 37 years old, discusses with her physician recent symptoms that she has experienced including blurred vision, numbness in her fingers and face, dizziness, fatigue and weakness. The physician performs multiple neurological tests and she is diagnosed with multiple sclerosis (MS).

  1. What is MS?
  2. Is MS a disease of the central or peripheral nervous system?
  3. What is the main cell structure affected in MS?
  4. How is the action potential of a neuron affected in MS?
  5. The origins of MS are not clear. What do scientists hypothesize to be the causes of MS?

Your assignment should be written in an essay format. The assignment requires you to include details from research including the course materials and sources you locate on your own. Remember to use APA format to cite your sources of information, both within parenthetical citations and also within a reference page at the end of the project.

Basic Writing Requirements:

  • Between 750–1000 words not counting the title or reference pages.
  • Include a title page, double space, font size 10 or 12.
  • Include a well-developed introduction and conclusion
  • Provide exceptional content.
  • Demonstrate superior organization: use logic.
  • Free of grammar and spelling errors.
  • No evidence of plagiarism.
  • Use APA style for all citations and references.
 
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