When things go wrong….Problems with Cell Parts

Round II

Mon, DEC 6, 2010

Today’s Objectives

• Consider real medical mysteries to examine what may be happening in a cell when individuals exhibit strange symptoms.

• Review progress about cell learning.

• Understand Science Fair Presentation Requirements

Bell-ringer (4 min)

• Compare/contrast prokaryotes and eukaryotes and give an example of each (will be collected and graded out of 4 points).

Baby Mike

• Baby Mike seemed to be healthy when he was born. Five days later, he stopped eating. His limbs became stiff and he looked like he was having a seizure.

• His urine smelled sweet like maple syrup.

• His parents rushed him to the hospital.

At the Hospital….

• What do you think the smell in his urine is?

• What may be happening?

• What tests should we take?

Possible Organs Affected

• Kidneys?

• Liver?

• Stomach?

Test Results• The doctors test Mike’s urine and find parts of proteins that should have

been broken down in the body. They are causing the sweet smell.

What are the dangers of having these proteins in the urine?

• The Doctors tell Mike’s parents that the only way he will survive is to never eat many foods like meat, milk, cheese, and eggs.

• Why is this?

MSUD: Maple Syrup Urine Disease• The liver breaks down proteins we eat so that we can

use these “building blocks” to make our own proteins with ribosomes.

• What organelle in the liver cells do you think breaks down these proteins?

• What is inside of this cell part so that it functions?

Some Enzymes (Proteins) break down Proteins (from Food) in the Lysosomes of Liver Cells.

• Where did these enzymes in the lysosomes come from?

Why is Mike missing these enzymes?

Treatments?

• Can Mike grow up and live a healthy, normal life?

• Or, will he die?

Strange Blindness• Lani is 17 years old. Over several months, she

notices that the vision in one of her eyes is getting blurry.

• One year later, she is completely blind.

• Doctors take a scan of her brain and eyes.. ….

Problems in the Optic Nerve• The doctor notices that almost all of the cells are working

normally, except the optic nerve – the group of cells that send messages between the eye and the brain.

• These cells aren’t sending messages!!

• What could be missing from these cells?

• Dr. Newman explains:• http://www.insidermedicine.com/arc

hives/INSIDERMEDICINE_VIDEO_If_I_Had_Lebers_Hereditary_Optic_Neuropathy_LHON_Dr_Nancy_Newman_Emory_University_3983.aspx

Leber’s Hereditary Optic Neuropathy

• In LHON patients, mitochondria in their optic nerve cells are no longer working, because they are missing an important protein they need to make ATP (energy).

• Where did Lani get this disease from?

• Will she ever see again?

What is the effect of carbon dioxide on Brassica rapa growth?

Ms. Novokhovsky• Hypothesis: If plants are

grown in an environment with higher levels of carbon dioxide, they will experience more rapid growth than plants grown in an environment with atmospheric levels of carbon dioxide.

Experimental Design

Group One15 Brassica rapa plants: 10 mL water/ day,

21 C (70 F), 390 ppm of Carbon Dioxide, 12 hrs of 2850 Lumen light.

Group Two15 Brassica rapa plants: 10 mL water/ day,21 C (70 F), 450 ppm of Carbon Dioxide, 12 hrs

of 2850 Lumen light.

Results

• After 35 days, plants in Group Two grew taller, but had few leaves and flowers.

• Explanation: Because plants require carbon dioxide for photosynthesis, plants that were given more carbon dioxide

grew more quickly.

Homework

• Prepare 3 power-point slides on your science project to present to the class tomorrow. Send these tonight.

• Make sure you are following all of the guidelines on the rubric for full credit. Presentation grade is worth 50 points.

• Reminder: D-Day tomorrow!