LB145Sec 001-004

Today’s Outline

• Tutorial Reminder• Homework #1: Results• Homework #2: Assigned• Organelles– Nucleus, RER, Golgi Apparatus, Cytoskeleton,

SER, Ribosomes, Lysosomes, Peroxisomes, Vacuoles, Mitochondria, Chloroplasts

• Match’Em Exercise

Last chance to register clickers!

• Register your clicker by the end of this week.

Exam Review- Tuesday Review Session (Trivia Game).- Special office hours: Wednesday morning.

Homework 1:

• Average = 6.24/7.00 (Excellent!)• Grades are on ANGEL along with my comments.• Next time – if you do not submit it to TurnItIn,

it will not receive a score.• Next time – academic integrity…– You were shown in class a good example of what a

violation of academic integrity looks like. Come see me if you have more questions or if you would like to see the de-identified example again.

This is an example of Academic Dishonesty

1. Academic dishonesty includes (but is not limited to):

1.3. plagiarism: representing the words or ideas of another as one's own in any academic exercise (e.g., papers, computer programming assignments, class presentation, or laboratory reports);1.4. submitting the same paper, or substantially similar papers, to meet the requirements of more than one course without the consent of all instructors concerned;

2. Instructors in Lyman Briggs are expected to take appropriate action in all instances of academic dishonesty….In cases of academic dishonesty, an instructor may take action consistent with his/her syllabus, including giving a failing grade on the assignment, giving a lower or failing grade for the course, and/or recommending additional disciplinary action.

[See website addendum under Academic Honesty]

Homework #2:

Northern European Folklore:Wehe dem Kind, das beim Kuß auf die Stirn salzig schmekt, er ist verhext und muss bald sterbe!"Woe to the child which when kissed on the forehead tastes salty. He is bewitched and soon will die!”

- Nucleus- Ribosomes- Rough Endoplasmic Reticulum (RER)- Smooth Endoplasmic Reticulum (SER)- Golgi Apparatus- Peroxisomes- Lysosomes- Vacuoles- Mitochondria- Chloroplasts- Cytoskeleton

Eukaryotes: Organelles to Live By

The Nucleus

Ribosomes

Ribosome and rRNA• rRNA is made in the nucleus.• Small and Large Subunit proteins are transported

INTO the nucleus. Where the ribosome is assembled.(below: protein in purple, rRNA in orange and yellow)

Eukaryotes have FOUR strands of rRNA.

5S5.8S28S

18S

Prokaryotes have THREE strands of rRNA.

5S23S

16S

What does this have to do with the lab?

Keeping RNAs Straight• mRNA

– MESSANGER RNA– Transcribed from DNA in nucleus.– Transported out into cytosol.– Interacts with ribosome where translation takes place and a protein is formed.

• rRNA– RIBOSOMAL RNA – Transcribed from DNA in nucleus– Binds to large and small ribosomal subunits in nucleus – acts as structural

support.– Exits nucleus (bound to ribosomal subunits) via nuclear pore.

• tRNA– TRANSFER RNA– Transcribed from DNA in nucleus– Exits into cytosol via nuclear pore– Picks up a specific amino acid (covalent bond) in cytosol and transfers it to

growing polypeptide chain.

Some proteins are made in the cytoplasm (cytosol) on “free” ribosomes

http://members.aol.com/SHinrichs9/abiopb/flow.jpg

The Rough ER

Some proteins are made on “bound”

ribosomes

Campbell 8e, Fig. 17.21They enter the endomembrane system

The Golgi Apparatus

The Endomembrane System: Manufacturing and Shipping Proteins

Insulin is Secreted via the Endomembrane System

Campbell 8e, Fig. 6.16

Cytoskeleton

Microtubules (green)

Microfilaments (red)

Nucleus (blue)

Molecular Components of the Cytoskeleton

A Motor Protein Generates Motile Forces

(Class of 1984)

The Smooth ER

Smooth ER

• Synthesize fatty acids and phospholipids.• Breaks down toxins/poisonous lipids.• Reservoir Ca+ ions.

Peroxisomes

Peroxisomes

• Center of oxidation reactions.– E.g. glyoxisomes oxidizing fat to store it as usable

energy.• Break down very long fatty acid chains to shorter

carbon chains.– These shorter chains are eventually shipped to

mitochondrion and used to produce ATP.

Lysosomes

Lysosomes

• Digestion packets full of enzymes. • Found in animal cells.• Fuse with vesicles or old organelles.• Often a very acidic environment.– Low pH.– Lots and lots of hydrogen ions.

Vacuole

Vacuoles

• In plants and fungi.• Sometimes used to aid in digestion.• Store water and help cell maintain volume.

Mitochondria

Mitochondria – Generates ATP from Glucose

Campbell 8e, Fig. 6.17

Chloroplasts

Chloroplasts – Generate G3P (glucose precursor) from sunlight and CO2

Campbell 8e, Fig. 6.18

Activity – Cells and Organelles

Coming Up Next Week:

• Homework 2 is due on Tuesday– The Case of Cystic Fibrosis– Upload to TurnItIn (no identifying marks)– Bring a copy to class (last four #s of PID)

• Tuesday: – Evaluate HW– Review for Exam 1.

• Exam #1 is on the 24th.