Test day

We had a test today in class an it took the whole period. 

Review for test #1

Today, the whole class revied concepts from basic chemistry and chapters 2.3 and 2.4 in the text book. 

Basic chemistry concepts: 

-valence electrons 

-isotopes 

-chemical equations 

Chapter 2.3 and 2.4:

- Carbohydrates

- disaccharide 

-polysaccharide 

- fatty acids

-unsaturated 

- saturated

-trans fat

-proteins

-amino acids 

-peptide

-polypeptide 

-enzymes 

-isomers

-structural 

-stereo

-geometrical 

-functions of proteins 

-groups 

 Then we had a formative quiz and went over parts of the lab and how to upload and create things on your website 

Testing 1,2,3

Today in class we went over the standards and some of the vocabulary we learned in the notes we took. 

Then we were given the choice between two labs. My group chose to do the macromolecule lab. 

This lab had four different tests you had to do and it has ten different substances you had to test. 

Test#1 Benedict : testing for sugars

1. Put control in one test tube 

2. Put each unknown substance into each of their own test tube

3. Add Benedict 

4. Try to boil them all at the same time

5. Observe and record data

Test#2 iodine: testing for carbohydrates

1. Fill spot plate with control and unknown substances 

2. Add a few drops of Lugol's solution 

3. Observe and record data 

 

Test#3 biuret: testing for proteins 

1. Fill the spot plate with control and unknown substances 

2. Add Biuret reagent to each

3. Swirl contents

4. Observe and record 

Test#4 Sudan III : testing for lipids 

1. Put each unknown substance and control on their spot plate 

2. Then put a drop of each on a paper bag

3. Wipe it of slightly

4. Check for residue 

5. Record data

Or

6. Add Sudan III to each unknown in the spot plate 

7. Observe and record 

Plant Cell Party

In class we learned about the many parts of plant cells and how they differ from other cells. Using this picture :

We described some of functions and purposes of the cell wall, phospholipids, glycoproteins, and glyclolipids. 

Glycoproteins - carbohydrate +protein 

- two layers of phospholipids- phosphate + fat 

- proteins embedded 

Proteins- main functions: transport, enzymatic activity (cause things to happen), signal transaction to nucleus about what is happening outside, and cell to cell recognition( by shape created by glycoproteins) 

We also reviewed osmosis, diffusion, and  a cell membrane.

Osmosis - movement of water across a semi- permeable membrane from an isotonic solution 

Diffusion- movement of molecules from a semi- permeable membrane (through proteins) 

Cell Membrane- semi- permeable determined by: 

- size 

-polar and non polar bonds in molecules 

The last activity in class was the house case where we were given symptoms of a potential patient and we had to figure out what tests to give and the diagnosis. 

Osmosis and Diffusion lab part 2

Today in class we continued to explore the concepts of diffusion and osmosis. We conducted two different types of experiments: one was to test the rate of diffusion  of KI through different size blocks of a substance and the other was to test the diffusion of a starch and glucose mixture.  Before we conducted the experiments, we graphed part three and part four of the experiment. 

1st experiment: 

1. Cut three different size blocks of the substance 

2. Then put them in three different size beakers 

3. Then pour KI over each one an make sure they are completely covered 

4. After about 15 minutes, take them out

5. Cut them in half and find the area of the block that didn't have KI in it 

6. Then find the percent of that area out of the total area 

Significance: 

We did this experiment to compare the diffusion rate and how size affects the diffusion rate.

2nd Experiment: 

1. Fill the cell with a starch and glucose mixture 

2. Test tap water for glucose and test mixture for glucose 

3.Then place the cell in a beaker and put in enough water to cover it

4. Then after about 15 minutes take 1ml of the water and put it into a vile 

5. Then add a drop of Benedict's substance to the vile to test for glucose

6. Then put the vile in boiling water and observe 

7. Then add iodine to the remaining water and cell 

8. The starch should react with the iodine and turn a dark blue color 

Significance:

We did this experiment to show that the glucose molecules can move thought the semi permeable membrane, while the starch molecules cannot because of their larger size. 

Osmosis and Diffusion Lab

Diffusion and Osmosis Lab

Featuring colored solutes and yams

For homework the night before, my class read about the concepts of diffusion and osmosis.

 

Diffusion: Molecules spreading out from a higher concentration to a lower concentration

 

 

Osmosis: Specifically water molecules moving from a higher concentration to a lower concentration through a selective membrane

 Our board that we used to explain these concepts in class

Then we stated the lab.

Procedure:

1.)Take 7ml of each Solute and fill small plastic tube (make sure to tie the very ENDS)

2.) Mass each of the six different solutes

3.) put each "cell" into a cup with distilled water (25ml)

4.) Mass them again( Make sure to dry them off)

5.) find the percent of mass change

 

Part 3 of lab

 



Procedure:

1.) Cut up yam/ potato into 24 pieces

2.) Place four pieces onto the scale and then record their mass

3.) Then place those pieces into a cup

4.) fill the cups with the same six solutes that you used in the last part of the experiment

5.) Observe and take mass the next day

6.) find percent of mass change

 

 

 





Water Everywhere

In Class today, we covered the basic principles of water and its special characteristics by reviewing objectives 8-11.

Objectives:

8.) covered in last post

9.) Cohesion- ability to bond with other water molecules, Adhesion- ability to bond with other things

10.) The concepts we had to explain:

-why coastal areas have milder climates than inland areas

 

Because water has a high heat capacity it takes a while to heat up and the gas in the air does not have a very high heat capacity and heats up easily

 

-why ocean temperatures fluctuate much less than air temperatures on land

 

Because water takes longer to heat up and air is a gas which doesn't take long to heat up. (same idea as the last question)

 

-why water forms a convex surface above a glass

 

Because water has a bent shape; therefore, creating this convex shape over whatever container the water is in

 

-why water will travel up a paper towel

 

Because of adhesion and cohesion- water bonds together, forming a string of water molecules. Then those water molecules bond with the paper towel molecules and climb upward

 

-why ice floats

 

Because when ice freezes, it forms a crystalline shape that creates more space between the bonds. This also lowers the density.

 

- why humans sweat and dogs pant

 

Humans sweat because we need to cool off by releasing water outside of our body using sweat glands

 

Dogs pant because they need to cool off the blood in their tongues in order to cool off. To do so, the heat transfers from the blood to the water on the tongue, then the water evaporates, taking the heat with it.

 

- why a water strider can walk on water

 

Because its feet have little hairs on them, creating more surface area which allows it to walk on the water molecules

 

We also used pennies to observe the different properties of water. Here are some pictures and video:

We can see the convex shape here

This is how water responds to a toothpick and shows us the surface tension

 

This is a video of me testing out the surface tension with a toothpick that had some soap on it

 

 

This is a video of me testing out the surface tension