Investigating Digestive Enzymes Lab

You guys were able to experience your first "read the procedure and DO it" kind of lab and we all managed to survive?!?!?  Friday we had the opportunity to share the results we observed in the three different set ups.  If will briefly detail the initial and final results here - but please go to Edline and click on the lab where I have uploaded a full presentation of your results.

Procedure A looked at the effect of temperature on the digestion of lipids.
Each test tube contained a pH indicator (that turns pink at a pH above 8), Olive Oil (a lipid), and a mixture of digestive enzymes.  Initial observations were the same for both tubes

One tube was placed at room temperature while the other was placed at body temperature (in an incubator) and set overnight.

Here were final observations

Procedure B also was testing the effect of temperature on enzyme action but this time it looked at enzyme activity on Starch.

Each test tube had a starch solution, a mixture of digestive enzymes, and an iodine solution.  The iodine solution turns a dark blue/black in the presence of starch.  Here is how all three started.

Test tube 1 placed at 5 degrees Celcius, 2 kept at room temp and
 3 placed in the incubator at 37 degrees Celcius (body Temp)

You can see that the one placed in ice is still a dark blue color
while the room temperature is a very pale blue and the body
temperature one is completely clear (meaning there is NO starch
left!!) 

And finally we had procedure C which looked at the effect of pH on enzyme activity.  In this case we looked at enzymes activity on proteins.

Each test tube received a piece of boiled egg white and pepsin (a proteolytic enzyme).  The changing variable in this case was the pH.  One test tube had an acid added to it (Hydrochloric acid), The second had pure water (neutral pH) and the third had a base added to it (sodium hydroxide)

Set up

The constant variable here was the temperature.  ALL of them made their way into the incubator to work at body temperature over night.

And here were final observations.  The protein which was placed in an acidic environment (like that of our stomachs) worked the best and completely digested the egg.  The one at a fairly neutral pH did not do much at all while the basic test tube had slight enzyme activity.

We will continue to draw conclusions about enzyme activity on Monday!!!

Continue with enzymes and pre-lab for digestive enzyme processes

Daily Questions from Wednesday were based around your notes on enzymes and their functions.  All of these were sample questions from the keystone exam.

Wednesday September 26th 

Which statement explains why large changes in pH can affect the functions of plant enzymes?

1.  Large changes in pH increase the rate of cellular chemical reaction.

2.  Large changes in pH provide the energy necessary to activate an enzyme

3.  Large changes in pH can denature an enzyme causing a change in its shape.

4.  Large changes in pH can cause an enzyme to react with a different substrate.

Z could be replaced with either pH or Temperature.
Both of these effect enzyme activity.

Molecule c would most likely be the substrate of this enzyme

 We continued the notes on enzymes yesterday and finished with how temperature effects enzyme function.  We then did some pre-lab work on digestive enzymes and today actually went through the lab.  This was the first time I had you guys actually READ through a lab and do it all yourself.  It was a BIT chaotic, and only one beaker was broken (my fault) but we were able to at least get the procedures done.  Once I have all the pics and we get final results I will post everything that happened during the lab.

NO DAILY QUESTION QUIZ TOMORROW!!!!!!! We will just continue to work through this lab!!

Enzymes - My kind of molecule! They are TOUGH and they are WORKERS!!

Tuesday September 25^th

Enzymes are CRUCIAL in allowing biochemical reactions to occur – How do enzymes aid these chemical reactions?

By LOWERING the activation energy required to start chemical reactions.  Without enzymes our bodies would not perform biochemical reactions quick enough to support life.

Enzymes have three main parts –

*What is the area binds a substrate?

 The "Active Site" - this is a restricted site on the enzyme where a SPECIFIC molecule involved in a chemical reaction bind.

By heating an enzyme up the shape of this site can be altered.  Why do you think this could this have a DRAMATIC effect on the function of the enzyme now?

If the shape of the active site is changed, the specific reactants that would normally fit  will not be able to bind any more.  For instance - take a look at the Enzyme Hexokinase (blue molecule) below.  This enzyme binds glucose (red molecule) specifically.  If after heating this enzyme, the active site changes, glucose will not longer fit and the enzyme will be inactive.

Using the graph below that displays enzyme action - determine which time interval the enzyme initially affects the chemical reaction.

It would have initial action during the 2nd time interval.  This is the point where activation energy is required for a reaction to occur.  The enzyme lowers the energy requirement for the reaction to them proceed.

After these daily questions we continued with the notes on enzymes.  Yesterday we focused mostly on what is required for a biochemical reaction to occur and the role that enzymes play in that.  Today we focused most on the different factors that effect enzyme activity.

**Just as a note - These were Friday and Monday's Daily questions if you didn't get those down!!  They were just wrap ups of proteins and nucleic acids.

Friday September 21^st 

Proteins are made up of what kind of subunits (Monomers)?  Amino Acids

Proteins are very complex and their functions are very diverse – what about proteins determines their function?

 Their Shape and how the amino acids interact with each other.

The last organic molecules we will be looking at are Nucleic acids – what are two examples of Nucleic Acids? DNA, RNA, ATP

Monday September 24^th

Nucleic Acids are made up of what kind of monomer? Nucleotides 

This monomer has three parts – what are they?   A sugar , a base (nitrogen base) and a phosphate group

What are two important functions of Nucleic acids?

Store hereditary (genetic) information - in the form of DNA and RNA.  They also act as energy carriers in the form of ATP.

Steroids, Jello and Cow Bones Oh MY!

Thursday September 20^th

Looking at the following chemical formula, what kind of biomolecule would you infer this to be?  Why?

               C₁₉H₂₈O₂              

 This would be an example of a lipid.  You can tell by the large number of Carbons and Hydrogens.  While there is a FEW oxygen molecules - it is not anywhere CLOSE to a 1:2:1 ratio.  This is in fact the structural formula of Testosterone which is a natural steroid hormone found in our bodies.

Proteins have MANY different functions – in fact proteins are pretty much involved in ALL cellular functions in one way or another.  The structures of these proteins are incredibly complex.  First, what subunits make up protein? Amino Acids

Next, what determines the function of different proteins?  The shape and how those amino acids are folded on top of each other.

After this we continued through the notes focusing this time mostly on proteins.  We saw that the range of proteins is ENORMOUS.  I had you jot down a couple of the following examples and let you listen to a podcast about the source of the protein found in Jello.  Here a link to the transcript of that Podcast

http://blogs.howstuffworks.com/transcript/what-exactly-is-jello-made-from/

Tomorrow I would like your "chemistry of Health" worksheet and writings.  We will also take a daily question quiz and finish up with organic molecules tomorrow.

Carbohydrates Vs Lipids

Yesterday we got through most of our discussion on Carbohydrates and that is why I based today's daily questions on that.

Wednesday September 19^th

Carbohydrates are made up of what three elements in what ratio? Carbon, Hydrogen, Oxygen in a 1:2:1 Ratio (Remember, Carbohydrate literally means "Water" of Carbon, for every Carbon atom there is 2Hydrogen and 1Oxygen (H2O) )

What could you infer about a carbohydrate that has 12 Carbons (such as sucrose)'s chemical Formula?

That it would be C12H24O12 (1:2:1 ratio)  We see that in fact sucrose's chemical formula is ACTUALLY C12H22O11 due to how it all bonds together, which is CLOSE to the 1:2:1 ratio but that will not always be exact)

Other than a source of energy – what other function do carbohydrates have?

It acts as structural support to plants (in the form of cellulose) and certain insect's shells.

It also acts as a "name tag" attached to the cell membrane of EACH of our cells identifying which cell's in our body they are AND WHOSE they are (which is why organ transplants are so complicated!!!)

Which can store more energy Carbohydrates or lipids?

LIPIDS!!! Why?!?!  Take a look at the following two molecules

Lipid

Glucose

You can see there lipid molecules are made up of MANY more Carbon-Hydrogen bonds and energy is released when bonds are broken.  Because of this, lipids have the ability to STORE more energy - than carbohydrates but the problem is, it is harder to GET to that energy and our bodies will work through our glucose stores FIRST.

To put this in "real" terms I mentioned to you guys today about my upcoming marathon and how generally I hit the "wall" around mile 21 or so (it STARTS around mile 18 and progressively gets worse)  The BIOLOGICAL reason behind the "wall" is, at that point I have pretty much used up ALL my glucose stores and my body is breaking WHATEVER biological molecules it can apart in order to release energy.  Which means PROTEINS (like in my MUSCLES) are getting tore apart to get energy. THIS is kind of what mile 21 sometimes looks like (this was my FIRST marathon - they have got much better since then ;)  Here is a link that describes it in even more detail. http://www.marathonandbeyond.com/choices/latta.htm 

Mile 21 in my FIRST marathon

Mile 23 in the last marathon I ran (yep - sporting
my Ellwood Gear!!)

After this we continued through the notes on lipids and started into the differences between saturated and unsaturated fats.  We will hopefully be starting a activity on this stuff by friday.

Great Job today guys!!

Importance of Carbon and start discussing Carbs

Tuesday September 18^th

Organic compounds that make us up are made up of many atoms of which element?  Carbon

Why is this element so useful in making macromolecules (large molecules)

It is relatively small - it is Kind (it likes to share it's electrons with many other atoms such as Hydrogen, Oxygen, other Carbon atoms and Nitrogen) and it can bond with up to FOUR other atoms at once.

How many valence electrons does this atom have that can be shared with other atoms?

4 - so therefore it wants to find other atoms that will fill that up (hence why it could bond with up to 4 other atoms)

The four primary biomolecules that make us up are:

Carbohydrates, Lipids, Proteins, Nucleic Acids

I had you guys watch the beginning of Hank Green's "Crash Course Biology" on Carbon.

Then we got through carbohydrates in the notes.  We will continue through these notes over the next couple days - remember - This friday we WILL have a daily question quiz!!!

Organic Molecules Introduction

First let's do a little catch up!!
Friday we did have the following daily questions
Friday September 14th 
Wednesday and Thursday of last week you guys didn't see me.  On Wednesday you got down all the notes for the next section and on Thursday you started into a supplemental reading from the National Institute of Health called "The chemistry of health".  This will help extend your knowledge of the chemistry of life that we have talked about into other areas such as "natures products" and pharmaceuticals.  

Water is able to resist drastic changes in temperature because it has a high Specific heat (heat capacity)

Why is this important to us? (As humans)

 Since we are made up of approximately 70-75% water, this fact allows us to minimize major temperature fluxuations in our body temperature.

Water is considered a "Universal Solvent"  This is because of how it disassociates when in solution. What two ions does water break into?

H+ (Hydrogen ion) and OH- (Hydroxide Ion)

Monday September 17^th 

Using your “Chemistry of health” answer the following questions.

What is one importance of Fats (lipids) in our bodies?

They provide insulation, they are major sources of energy storage, they are a key part of the cell membrane as well as many others that we will be discussing in the next couple days.

What are sugars made up of? (it’s the reason carbohydrates are harder to make than proteins)

Saccharides (sugars)

What is the role of carbohydrates attached to the cell membrane?

They act as "name tags" identifying each cell (again - we will be talking about this in great depth over the next couple days and this specific example will be referred to when we learn about the cell membrane)

After going over these daily questions I had you guys talked a little about the molecule Capsaisin and told you my Jalapeno fingers story.  BEWARE!!!  Do NOT stick your fingers in your eyes after cutting up Jalapeno's!!  WHY???? Well take a look at the following molecule.

This "little" molecule is made up of a LONG change of Carbon and hydrogen. We will see in the next couple days that this is a very typical lipid molecule.  Here is the thing with Lipids - they are NON-polar, therefore the watery "saline" solution that is produced by our eyes (Also known as TEARS) will NOT break this down.  So therefore it will hang out in your eye for a while...... NOT a good time!   

Alright - after THAT fun story I had you guys watch one of the "Crash Courses" on Biological molecules.  I asked you to refer to the notes you have already taken and add any key ideas or terms you heard him describe.  We will be going through these notes together in class over the next couple days and I hope to get into a couple activities.  Half Day for you guys tomorrow!!

Finishing up Properties of Water

Tuesday September 11^th

Water will form hydrogen bonds with other substances such as glass, soil and plant tissues. The term for this type of attraction is known as Adhesion

A combination of this and Cohesion can cause water to ‘defy gravity’ by moving UP narrow tubes (such as the roots of trees) in a process known as Capillary Action

**When we added soap to our pennies we were not able to get as much water on them – what do you think the soap did to the water? (Hint:  What causes cohesion)  The hydrogen bonds that hold water to each other are broke apart by the soap.  Because of this, the water is less "cohesive" and has a decreased surface tension.  This fact is why water alone is NOT a good cleaner since it really is just attracted to itself.  Once the hydrogen bonds are broken it is now able to be bond with other molecules to allow better "cleaning" (So wash your hands with water and SOAP otherwise you're not doing much cleaning!!!)

After this we continued through our notes on the properties of water.  You will continue through these tomorrow when I am out and then move into organic chemistry notes on Thursday.  Friday I will discuss all that you write down the two days I will be out.
Monday September 10^th

 *Water can and WANTS to form bonds with how many other water molecules?
4

*Waters attraction to other water molecules is known as Cohesion

*The term for how water “pulls in” at the surface to form a “film” is known asSurface Tension

Cohesion and Surface Tension Activity

 After learning what cohesion and surface tension was - we started to see it in action.  Here's some pics on how it went.

Remember Cohesion is waters attraction to other water molecules.  It wants to bind with FOUR other water molecules.  At the SURFACE of the water there is no other water molecules ABOVE, so it holds tight to the what it can below!

First I had you fill the jar up to the VERY top
with water.

So that it was actually slightly
OVER the top of the Jar

Then you slowly added pennies
into the already full jar

They you saw how many would fit
before it overflowed.

You were able to really "see" how attracted water is to itself as you were able to put a lot of pennies into the jar.  Again, the key thing to remember is that this property of water is all due to the HYDROGEN BONDS holding them together.  Until the pressure from the pennies below is greater than the attraction to each other, they will remain bonded to each other.

Until then - a "film" forms on the top of water that can hold a bit of weight.  I then had you guys try and float a pin on top of the water to show the strength of these hydrogen bonds.

Wonders of water Day 2

Friday September 7^th

Draw and label a water molecule 

What type of bond holds together this water molecule?

Because of this there are “partial” charges associated with it.  Which end acts +, which acts -? (Label those)

Using the models in your tubs – make 5 water molecules then place how you think 1 would bond with 4 others.

 What type of bond holds two water molecules together?

Your pop-it bead water molecules.  See how
the Hydrogens bond with oxygen and vice
versa - you will never see a Hydrogen bonded
with hydrogen of another water molecule.

Remember EACH of these would then be bonded to four Water
molecules which leads to a very complex crystal form

We then took one slide of notes on Cohesion and surface tension then got to see that in action!  Check the next blog post for pics on this activity.  (Remember - get notes off Edline if you are absent)

Wonders of Water Day 1!!

Thursday September 6^th

Based on this cartoon – What type of Bond is this “marriage” depicting?
An ionic bond since he is GIVING his electrons away.  Remember - I told you a way that I was taught to remember Ionic bonds is "I OWN it."  He GAVE her his electron so now she OWNS it!

What if instead the “boy” atom said “I do, Let’s share our valence electrons baby”  Which type of bond would it be referring to?
This would be a covalent bond.  Remember I told you that the prefix "co" means together, share or both.  In covalent bonds electrons are SHARED between two atoms.

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After that we started into our discussion on water and its INCREDIBLY unique properties.  First I had you watch the following clip from the Waterboy.... WHY?!??!!  Because we are going to see that water does NOT suck and Gatoraide wouldn't have the effect it did if water wasn't the amazing molecule it IS!

We are in for some hands on stuff over the next couple days!!!
It may be hot in here - but we'll make the best of it :)

Then we started into notes about water.  Most classes got to the point of drawing out water molecules, seeing what makes it "polar" and then made some water molecules with pop-it beads.

Making water molecules out of pop-it beads

Note the "mickey mouse" shape of the water molecule.
This is due to the fact that water is held together by
POLAR Covalent bonds - so the electrons are shared
unevenly!!

4 perfect little water molecules!
Tomorrow we will see how they interact with each other