agenda 10/24/11 1) grade free response questions 2) review for test using study guides, review...

Agenda 10/24/11

1) Grade free response questions 2) Review for test using study guides, review manuals, and vocab

cards – I check review manuals while you review

Homework Study for test tomorrow – focus on enzymes, cell respiration, and

photosynthesis. You can check out study guides if you like.Lab Report due Friday 10/28 - you only need to write about 4B and

include that graph but be sure to make hypothesis, give results, and analyze data for cuvettes 2-5

Chapter 11 & 12 Notes and self-quizzes due Tuesday – recommend get 11 done during week and 12 over weekend.

Agenda 10/25/11

Cells and Metabolism Unit Test- Good Luck!!!

Homework – Lab Report due Friday 10/28 - you only need to write about 4B and


Chapter 11 & 12 Notes and self-quizzes due Tuesday – recommend get 11 done during week and 12 over weekend

Agenda 10/26/11

1) Cell signaling animations (Activities 11A-11E) from student CD-ROM in book

2) Test corrections – mandatory to hand in. If you scored below 80%, you need to be sure you do these well even if it means coming in on your own time!

Homework – Lab Report due Friday 10/28 - you only need to write about 4B and



Agenda 10/27/11 Finish cell signaling – put it all together Brief review cell cycle and mitosis using CD-ROM animations Cell Cycle Regulation Cancer (may do tomorrow)

Homework - Lab Report due tomorrow - you only need to write about 4B and



Cell signaling and Evolution

In yeast and bacteria, cell signaling is very similar to multicellular organisms

Yeast use it to find each other for sex Bacteria use it to aggregate as spores in

times of low nutrients

Cell signaling has remained important in the microbial world. Myxobacteria, soil-dwelling bacteria, use chemical

signals to communicate nutrient availability. When food is scarce, cells secrete a signal to

other cells leading them to aggregate and form thick-walled spores.

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Fig. 11.2

Can classify cell signaling based on distance

Paracrine = local ex:growth factors & NT’s

Endocrine = far, hormone travels in blood to target cells

Direct Contact – impt. in embryo dvpmt and immune system

Three stages of cell signaling In reception, a chemical signal (ligand) binds to a

cellular protein, typically at the cell’s surface. In transduction, binding leads to a change in the

receptor that triggers a series of changes along a signal-transduction pathway.

In response, the transduced signal triggers a specific cellular activity.


Fig. 11.5

Yesterday, we saw the different types of receptors - what were they? G protein-linked, tyrosine kinase, ligand-

gated ion channel, and intracellular

A G-protein-linked receptor consists of a receptor protein associated with a G-protein on the cytoplasmic side. The receptor consists of seven alpha helices

spanning the membrane. Effective signal

molecules include yeast mating factors, epinephrine, other hormones, and neurotransmitters.


Fig. 11.6

Signal Transduction

Protein kinases phosphorylate other proteins/enzymes which usually activates them (can deactivate though)

Have to have a way to turn off response -Protein phosphatases remove the phosphate group and inactivate the protein/enzyme to shut down the response

The balance of these 2 regulates the activities of the cell


Fig. 11.11

Second messengers (small, non-protein signal molecules) – what were the 2 we saw yesterday? cAMP and Calcium ions (usually Ca++ low in cell)

Certain microbes cause disease by disrupting the G-protein signaling pathways. The cholera bacterium, Vibrio cholerae, colonizes

the the small intestine and produces a toxin that modifies a G protein that regulates salt and water secretion.

The modified G protein is stuck in its active form, continuously stimulating productions of cAMP.

This causes the intestinal cells to secrete large amounts of water and salts into the intestines, leading to profuse diarrhea and death if untreated.


Cell Response 3 examples from yesterday= glycogen

phosphorylation, microtubule formation, transcription factors

Signal amplification

Specificity The response of a particular cell to a signal

depends on its particular collection of receptor proteins, relay proteins, and proteins needed to carry out the response.


Fig. 11.18

Rather than relying on diffusion of large relay molecules like proteins, many signal pathways are linked together physically by scaffolding proteins. Scaffolding proteins may themselves be relay

proteins to which several other relay proteins attach.

This hardwiring enhances the speed and accuracy of signal transfer between cells.


Fig. 11.19

Last paragraph of Ch. 11

Let’s read it, then go on to Ch. 12 Mitosis figures, p. 218-219 and cell cycle figures from Bio

The Cell Cycle

• Interphase

• G1 phase

• S phase

• G2 phase

• Mitosis

M phase

• Cytokinesis

cell membrane or cell wall

divides

growth

growth and preparation for mitosis

The Cell Cycle

Cell Cycle Regulation

Agenda 10/28/11

Peer grade lab reports Cancer Test corrections if time Or work on Ch. 11 and 12 notes and self-

quizzes – due Tuesday

Homework-Chapter 11 & 12 Notes and self-quizzes due

Tuesday

agenda 10/24/11 1) grade free response questions 2) review for test using study guides, review...

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