May 8th, 2012

Today in class: For the entire period, we worked on the What Nutrients are in Foods? lab (which is a separate packet from our regular unit packet). Mrs. Andrews also collected our "Design a Quiz" projects.

As far as homework goes: ~ Finish the nutrient lab that we worked on in class today
                                             ~ Work on review packets (TEST this thursday)

NEXT SCRIBE: Emily

As you probably all know, the purpose of the Nutrient lab was to test different foods (about 10 of them) for the presence of macromolecules (particularly starch, simple sugars, protein, and fats or lipids).  Because of the many different parts to this lab, your group of four (which were predetermined) had to divide up the work, so one person would find the results for each test, all working at the same time.  At the end of the period, the individual groups met with each other and exchanged data from each test.

In part 1 of the lab, your job was to set up the control for the various experiments.  The iodine test was first, where you observed the color change when with the mixtures starch and water, water and Lugol's iodine, and starch, water, ad Lugol's iodine all together.  If the mixture turned DARK PURPLE, that would be an indication that simple or complex starches were present (as it should have happened with the mixture of all three substances in this first experiment--the rest of the tests should have provided results that indicated there was no starch present).

To test for simple sugars, you had four different test tubes, two contained the mixture of glucose and Benedict's solution, and two contained the mixture of water and Benedict's solution.  One of each mixture was to be heated, and the other two were just supposed to be mixed together and observed.  Every one of the test tubes should have provided you with a negative result EXCEPT the test tube that had glucose and Benedict's solution that was heated--the color of that particular mixture should have been red, testing positive for glucose.

Next, you had to test for proteins.  The three test tubes in this experiment had the mixtures egg albumen, egg albumen and Biuret reagent, and water and Biuret reagent.  If the solution turned PURPLE, then this was an indicator for the presence of protein (the rest should have had negative results).


Lastly, you had to test for lipids.  One square of an unglazed brown paper bag should have been labeled "oil" and the second, "water."  You then had to wait until each substance evaporated to see whether or not the paper was translucent (light can go through, but one cannot see a clear image through the translucent substance)--if it was, lipids were present.  If not, than there were no lipids in the substance (distilled water tested negative, the oil tested positive).


After all of these "control tests," we had to perform the same experiments to test foods for each of the four different macromolecules (9 listed substances, and 1 from home).


To review, Benedict's test is an indicator for simple sugars, Biuret's test is an indicator for proteins, Lugol's iodine solution shows the presence or absence of starches, and an unglazed paper bag can be used to test for lipid (fats).


Think about this:


Which of the four macromolecules from the lab could be present in this chicken dinner?

This is basically what we did in the lab today--just think about what is in the food we eat and how the digestive system breaks it down/absorbs its nutrients! :)

Friday March 16th, 2012

As usual, we started out today's class with the "Fast Plants" lab (spending about 5 minutes on it). Right after, we continued working on our "Flowering Plants" lab, which is pages 19-34 in your Unit Packet.

Fast Plants:

Just water all of your plants, measure and record your measurements (of the stem) for each plant, and add GA to the plant leaves that call for it in the lab.

Flowering Plants:

In this 2-day lab, we basically just studied the anatomy of different monocot and dicot plants, while recognizing the differenced between the two types. It is necessary for you to know what the differences are between the stems, roots, and overall appearance (to the unaided eye as well as the aided eye) between monocots and dicots.

Here's a little review of key terms for this unit:

1. Xylem: Part of a plant's vascular system; the xylem conducts water and nutrients throughout the plant.
2. Phloem: Part of a plant's vascular system; the phloem conducts sugars throughout a plant's system.
3. Stomata: Slits on the underside of a leaf that allow for the exchange of gases (such as CO2 or water vapor).
4. Pith: The soft/spongy tissue in plants (serves as a kind of storage space for plants).
5. Angiosperm: A kind of plant that flowers and that has seeds enclosed in a carpel.
6. Root: The part of a plant that attaches itself to the ground to give the plant support and that absorbs nutrients and water.
7. Shoot: The part of the plant that consists of the stem, leaves, and the other parts of a plant (of which are typically above ground).
8. Leaf: A part of a plant that is typically green and blade like that is attached in some way to the shoot of a plant.

Homework for today:

• Work on UP p.19-34 (due 3/19)
• UP p. 41-54 (due 3/19)
• WILDLAND PROJECT (should finish by end of the week)
• Yellow CH28 study guide (Due 3/19)
• Read CH 29 (due 3/20)

Note: Unit Test is on 3/23--this week on Friday!!! STUDY :)

February 21, 2012

Today, we turned in our Hydra/Planaria lab (and also reviewed the answers to the questions), and we got back pages 15-18 and 11-14, and the Lab #44.

We also completed pages 7-10 in our note packet, all about the protist kingdom--extra info can be found in Chapter 15, pages 311-316 in our textbook. To sum up all the information, with key points as written in our packet:

• Protists are the first eukaryotes to evolve from prokaryote (bacteria) ancestors; they are much more complex than prokaryotes.
• How did eukaryote cells, as well as their membrane-enclosed organelles, evolve?
• 2 theories of these processes:

1. All organelles (except mitochondria and chloroplasts) evolved from inward folds of the plasma membrane of a prokaryotic cell.
2. Endosymbiosis: Largely developed by Lynn Margulis of the University of Massachusetts:

• "Chloroplasts and Mitochondria evolved from small prokaryotes that established residence in other, larger host prokaryotes."
• Mitochondria evolved 1st

• Protists vary in structure and function more than any other group or organism
• MOST are unicellular, but some are colonial or multicellular.
• The four major categories are:

1. Protozoans: They ingest food and thrive in all types of aquatic environments, including wet soil and the watery environment inside animals (parasites).
2. Slime Molds: Resemble fungi in appearance and lifestyle, but are NOT closely related at all... Role=decomposers
3. Unicellular Algae: Photosynthetic protists (have chloroplasts)--they support food chains in freshwater and marine ecosystems.
4. Seaweeds: Large, multicellular marine algae--used for a variety of human foods (for anything from sushi wraps to ice cream!)

Next, we filled out unit packet page 33, "Examining a Phylogenetic Tree", as a class. Lastly, we did a lab on page 35 in our unit packets, in which we classified real organisms (around the classroom--from centipedes to scorpions) based on their appearances into the correct phylum.

The homework for tonight is:

• To finish the "General Classification of Invertebrates" lab (pages 35-38)
• Prep for labs on pages 45-54
• The "Nature" assignment (due 3/2)
• And to read CH 17 if you haven't already!!!
• (It also might be a good idea to read up on pill bugs, just to get a little background knowledge for an upcoming lab)

Next Scribe: Austin

October 21st, 2011

Assignments due for today:

Bacteria labs analysis

pp.31-32 in the UP packet (Identifying Agents of Disease)--review for friday's test!!!

Assigned today:

Spice lab I-V (data tables)--10/25

Read Chp. 24 p.528-543 (complete backside of wksht)

Disease video due 10/31

Study for test on 10/28!!

Received a "study guide" for bacteria and viruses

Today in class, we watched a germ theory video and filled in our note packet up to page 23.

The germ theory is that a microorganism causes a disease (germs).

Be familiar with:

diptheria tuberculosis mumps

the common cold whooping cough pneumonia

influenza poliomyletis meningitis

malaria rabies ringworm

typhus infectious mononucleosis tetanus

chicken pox AIDS Rocky Mountain spotted fever

amebic dysentery streptococcal sore throat German measles

Botulism Athletes foot measles (rubeola)

Some key points in our packet:

• Nonspecific defenses (when the body doesn't distinguish one infectious microbe from another):

First line of defense= 1. skin

2. Mucous membranes (ex. eyes water)

3. secretions of skin and mucous membranes

Second line of defense= 1. Phagocytic (cell-eating) white blood cells

(part of the lymphatic 2. Defensive proteins

system) 3. The inflammatory response

• Specific defenses (immune system--when the body recognizes the pathogen):

Third line of defense= 1. Lymphocytes (white blood cells)

(part if the lymphatic 2. Antibodies

system)

A. Nonspecifics have two types of defense: External and internal.

Internal defenses are like the external's backup--they defend when an intruder gets by

the external barriers.

A type of internal defense is an interferons: they slow/stop viral replication

Where an infected cell "calls for help" and a neighboring cell sends proteins to inhibit

viral replication.

The inflammatory response= when tissue is damaged.

You know when the immune system is working when the injury (such as a small cut)

becomes red, swollen (because of blood vessels dilating) , and warm to the touch.

The lymphatic system consists of a network of vessels (similar to those of the circulatory system) and lymph nodes.

Its two main functions are to return tissue fluid to the circulatory system and to fight infection. It is the main "battle ground" for when the body is fighting infection.

B. Specific defenses: for when nonspecifics fail.

Immune system recognizes and attacks specific intruding microbes:

bacteria pollen parasitic worms

cancer cells house dust cells of transplanted tissue

protozoa mold spores

(all allergies)

Key players= antigens (elicit immune response) and antibodies (proteins found in blood plasma--mark invaders: neutralization and agglutination)

Antibody

Variable portion= there are two variable portions to each antibody so they can latch on to two different invading microbes. If enough accumulate and "clump" together (agglutination), the microbes cannot function.

STUDY FOR TEST:

Notes packet

bacteria/virus sheet (p. 31-32 in UP)

"study guide" handed out in class

NEXT SCRIBE: Sean

9/23/11

Today in class, we picked up where we left off in our yellow notes packet (from "What is an ENZYME?"). Some key vocabulary as defined in the packet:

1. Enzyme: specialized proteins which function as catalysts
2. Catalysts: speed up the rate of a chemical reaction without being used up itself (it is reused, or recycled)
3. Activation Energy: the amount of energy needed to stimulate the reactants to react in a chemical reaction.
   
4. pH: (potential hydrogen) the measurement of how acidic or basic a liquid solution is
5. Ion: a charged particle that has either gained or lost an electron
6. Acids: chemical compounds that give H+ ions to solutions
7. Bases: compounds that accept H+ ions and remove them from a solution
8. Neutral: a solution in which the concentration of H+ and OH- ions are equal
9. Substrate: a specific molecule that an enzyme recognizes to bind with

And then important ideas we discussed in class (also from the yellow notes packet):

• Protein Structure:

a. Primary Structure:

a SPECIFIC sequence of amino acids (any slight change could cause the protein to

not function properly)

b. Secondary Structure:

Held together by hydrogen bonds along the backbone (an alpha helix/pleated sheet)

c. Tertiary Structure:

Held together by chemical bonds between the side groups (3D in shape)

d. Quaternary Structure:

protein that consists of 2 or more polypeptide chains + the bonding of these chains

• Proteins are polymers of amino acid monomers
• Types of proteins= structural, storage, contractile, transport, defensive, signal, enzymes (important for our bodies to function)

• Ways to speed up a chemical reaction:
  

1. heat mixture in a lab (however, not for cells--too much heat may result in the shutting down of cells)
2. decrease in activation energy:

the enzyme binds to the reactant molecules making it easier to break their bonds

• Enzymes are affected by:
• temperature
• pH
• concentration
• specificity

Homework:

• UP p. 7-18 ("Enzymes are Everywhere" lab)
• Extra Credit Sheet
• Internet Biochemistry Tutorial p. 4 (for review)... Site on p. 5, #3 under "More Internet Activities"

Also, we got our Chapter 18 and 19 quiz back. Be sure to prepare for Monday's "Enzymes are Everywhere" lab!

Next Scribe: Michael