Milk, Juice, Carrot Lab

Milk

Introduction: The purpose of this experiment is to find out what will happen to milk that is left at room temperature for 4 days.

Hypothesis:  A ½ cup of milk left out in room temperature for 4 days will develop a sour smell and will curdle.

Procedure: I poured ½ cup of cold whole milk into a 1 1/2 cup glass mason jar. The milk was poured into the mason jar as soon as I took it out of the refrigerator. I then set the mason jar behind my kitchen sink for four days. 

Results: The milk smelt a little off but not sour like I had expected it to. The milk did not curdle as much as I thought it would. There was a slight ring around the glass and it had just begun to curdle on the bottom.

Day 1

Day 2

Day 3

Day 4

Day 4 

Conclusion: I think that the reason the milk did not sour and curdle is because it was not in a warm enough spot. Milk contains bacteria that grow by changing the lactose sugar into lactose acid. When the bacteria changes the sugars into acid the souring and curdling happen. (Kagan) This happens when milk becomes old or when it is in warm temperatures. I think if I had kept my milk in a different spot or performed this experiment in the summer my hypothesis when have been proved.

Juice

Introduction: The purpose of this experiment is to see how the molecules in water react when cranberry juice is added to the water. This will be done three times. The first time will be room temperature water, the second will be ice water and the third will be boiling water.

Hypothesis:  A ½ cup of juice poured into ice water, room temperature water or boiling water will mix easily with the water.

Procedure: I measured 1 cup of tap water and placed it in a glass. Then I measure ½ cup of room temperature cranberry juice. I poured the cranberry juice into the water and watched the reaction. Next I placed 5 ice cubes into a measuring cup then added water until it measured 1 cup. I placed the 1 cup of ice water into a glass and added ½ cup of room temperature cranberry juice to it. Then I measured 1 cup water and poured it into a glass. I heated the water to boiling in the microwave. Then I added ½ cup of room temperature cranberry juice to it.

Results: You could see the cranberry juice mixing with the water when it was poured into the tap water. It traveled down and then began to spread until it was equally mixed.  When the juice was poured into the ice water, the result was the same. I could see the cranberry juice moving in the water as it was mixing together. I could hear the ice cubes making a cracking sound and it seemed to mix a little slower than with tap water. When the juice was poured into the hot water that had been boiling, the water began to bubble a little again. The juice also appeared to move faster through the water and mix faster.

Juice added to room temperature water

Juice added to ice water

Juice added to boiling water 

Conclusion: The juice did mix easily with the water in all three experiments. It mixed the fastest with hot water and the slowest with cold water. The reason the juice mixed faster with the hot water is because the molecules in hot water move faster than in cold water. Also they are further apart so the juice was able to mix faster. The molecules in cold water are closer together so the juice mixed a little slower. (Kessler, Galvan and Boyd) So my hypothesis was correct in that the juice mixed easily, however it mixed the easiest with boiling water.

Carrot

Introduction: The purpose of this experiment is to determine what will happen to a carrot soaked in salt water for 24 hours and what will happen to a carrot soaked in water for 24 hours.

Hypothesis: A cut carrot placed in water will stay the same size after a period of 24 hours. A cut carrot placed in salt water will begin to wilt after 24 hours.

Procedure: I filled a glass mason jar with 1 and ½ cups of water. I added one teaspoon of salt and labeled the jar salt water. I cut a carrot in half and measured the length and width. The length was 4 1/8 inches and the width was 7/8 inches. I tied a piece of string tightly near the end that had been cut then placed it in the salt water with the cut side down. I filled up another mason jar with 1 and ½ cups water. I labeled that jar fresh water. I cut another carrot in half and measured the length and width. The length was 3 6/8 inches and the width was 7/8 inches. I tied a piece of string tightly near the end that had been cut then placed it in the fresh water with the cut side down.

Results:  I removed the carrot from the salt water 24 hours later. When I checked the string it was a little loose and I was able to easily slip it off. The carrot was easy to bend. It was flexible and rubbery. The end that had been cut felt a little slimy. The measurements were about the same with the length being 4 1/8 inches and the width just a tiny bit less, maybe 13/16. I then took the carrot from the fresh water. The string was very tight. The cut side didn’t feel any differently and the carrot was very firm and I was not able to bend it at all. The measurements were the same, the length was 3 6/8 inches and the width was 7/8inches.

Conclusion: The carrot in the salt water became flexible due to the water inside the cells moving out of the carrot. The water was moving out in an attempt to “equalize the water inside and outside of the carrot.” (Drane, Eppich and Ruch) The carrot placed in fresh water should have the opposite happen, the water will move into the cells in the carrot. My hypothesis for the carrot placed in salt water was correct. My hypothesis for a carrot placed in fresh water was not.

Carrots soaking

After soaking for 24hours. Strings already removed. 

Works Cited

Drane, Carol Ann, Lois Eppich and Mary Lee Ruch. Find another Lesson Plan? . n.d. 11 Feburary 2012 <www.create.cett.msstate.edu/cosee/cosee-lplan_view.asp?articleID=15>.

Kagan, Mya. Why does milk get sour? . n.d. 9 February 2011 <http://whyzz.com/why-does-milk-get-sour>.

Kessler, Jim, Patti Galvan and Adam Boyd. Middle School Chemistry. 2012. 12 February 2012 <http://www.middleschoolchemistry.com/faq/#authors>.

Unit 1 Compilation

Table of Contents:

Characteristics of Life

Living Things Are Classified By Their Characteristics

Features of Humans

Scientific Process

Matter Is Made From Elements

Water is Essential For Life

Hydrogen Ions

Organic Molecules

Carbohydrates

Lipids

Proteins

Nucleic Acids

Cells

Plasma Membrane

Inside the Cell

Tissue

Organs and Organ Systems

Works Cited

Characteristics of Life

v The molecular composition is different in living things than in nonliving things

v All living things need energy

Ø  Energy is made by metabolizing raw materials

v All living things are made out of cells

v Living things are able to maintain an internal environment so that life can exist

v Living things react to external conditions

v Living things grow

Ø  How much a thing grows is determined by DNA

v Living things change over time

Living Things Are Classified By Their Characteristics

 (Whittaker)                                                             

In 1969 scientists began classifying living things using the five kingdom method. The five kingdom method looks at things such as whether or not there is a nucleus, how many cells the living organism has and what type of metabolism the living thing has. More recently scientists have begun to use a higher classification method known as domains.  Humans are classified under the animal kingdom subgroup known as vertebrates. 

Features of Humans

v Humans are able to walk upright on two feet while carrying things in their arms

v Humans have thumbs that are able to touch the other fingers on the same hand

v Humans have large brains

v Humans have developed a complex written and verbal language

Scientific Process

The scientific process or scientific method is a method that is followed when finding out if an idea or hypothesis is true. The steps are observe, form a hypothesis, make a prediction you can test, perform an experiment then make changes to your hypothesis if necessary and come up with a new experiment. Once the hypothesis has been sufficiently tested it becomes a theory. There are different sources of finding and reading about scientific information. Some forms are very technical and written for other scientists. Some are written in a way that most people can understand with accurate details. Some are written in a way most people can understand but do not give the details. When hearing something new in science be skeptical and preform your own research. Learn how to read graphs and use the statistics. Make sure you are looking at scientific evidence and not someone’s opinion. You need to be able to pick out what is a fact and what is the conclusion and you need to know the difference between correlation and causation. It is important to understand the scientific process and how to accurately interpret it so that we can make informed decisions.

 (Baran)

Matter Is Made From Elements

Matter is something that has substance and occupies space. Matter is made from elements.  Elements are the purest form of matter and cannot be broken down further. Elements are composed of atoms. Atoms are the smallest part of an element that still has the properties of the element. The nucleus is the core of an atom. It is made from protons and neutrons. Electrons, which are particles, move around the nucleus.                                                           Molecules are 2 atoms that have joined together to create something. There are 3 types of chemical bonds. One type is a covalent bond in which 2 atoms share a pair of electrons. Another type is ionic bonds which is when an atom gives all of its electrons to another atom or takes electrons from another atom. The third type is a hydrogen bond.

                            (Thomas Jefferson National Accelerator Facilty-Office of Science Education)

Water is Essential For Life

Water is a solvent and there are a lot of different chemical reactions that take place in water. There are hydrophilic molecules which react well with water and hydrophobic molecules which do not mix with water. Water is able to absorb and hold heat. It is important to regulating our body temperature. There cannot be life without water.

Hydrogen Ions

Hydrogen ions are formed when the hydrogen and oxygen atom are broken apart in water. The pH scale is the way that the amount of hydrogen ion in a solution is measured. Buffers are sometimes added to the solution to try to prevent or lessen the change in pH.   

  (Ophardt)

Organic Molecules                      

Organic molecules include carbon and other elements and are made with covalent bonds. Organic molecules are not organic like we know the word. The can be synthetically made. Macromolecules are built using a method called dehydration synthesis and broken down by a method called hydrolysis. There are four classes of organic molecules found in living things. They are carbohydrates, lipids, proteins and nucleic acids.

Carbohydrates

Carbohydrates are made from carbon atoms and have hydrogen and oxygen connected to them. Carbohydrates are used for energy. Monosaccharide is a carbohydrate that contains one sugar and is referred to as a simple carbohydrate. Ribose, deoxyribose, glucose and fructose are all monosaccharide’s and are important in humans. Oligosaccharides are monosaccharide’s that are formed together through dehydration synthesis. Some common oligosaccharides are sugar and lactose. Polysaccharides are complex carbohydrates and are made from thousands of monosaccharide’s are formed together by the dehydration synthesis. 

Lipids

Lipids are molecules that do not dissolve in water. They include triglycerides, phospholipids and steroids. Triglycerides are made from glycerol and three fatty acids, which are hydrocarbons. Triglycerides are important for storing energy. Phospholipids are made from glycerol and two fatty acids and a charged phosphate. Steroids are made from three six membered carbon rings and one five membered carbon rings. Cholesterol is a steroid and something our bodies make in addition to the amount we consume from our diet.

Proteins

Macromolecules made from amino acids are proteins. There are 20 different amino acids that proteins for humans are made from. Humans usually are able to get enough of the 20 amino acids through diet. 11 of these proteins can be made by our bodies if needed. Proteins are made by dehydration synthesis. Protein has 3 or 4 structures. There are thousands of different proteins in the human body and they all have different proposes.

Nucleic acids

DNA is the genetic makeup of any living thing. RNA does what the DNA tells it to and tells the body how to produce proteins. They are both made from nucleotides.

 (DNA & RNA Art Print)

Cells

Cells are enclosed in a plasma membrane. There are two different groups that cells are placed in. These are eukaryotes or prokaryotes. Human cells are called eukaryotes and so are most living things cells.

.                                                                                        

(Pearson Education)

Eukaryotic cells are structured very similarly regardless of what type of living thing they come from. The differences in structure are due to what their function is not what living thing they are found in. All cells are so small they cannot be seen without magnification. Cells are made so that they can move and not lose their shape. The parts of the cell that help it move around are called the cytoskeleton, cilia, flagella and centrioles.

Plasma Membrane                                                                                                                                The plasma membrane around the cell lets some things through to the cell and lets some things out of the cell. Other things it will not let go in or out of the cell. The plasma membrane protects the cell so there can be life inside it. Molecules go through the plasma membrane in three different ways. The first way is by passive transport. Passive transport happens when the molecule passes through it without the cell using any of its energy. This process is referred to as diffusion. There are only certain molecules that are able to pass through this way. Passive transport always travels in a downward direction. Another way molecules go through the plasma membrane is by active transport. The cell uses energy during active transport and travel in the opposite direction of passive transport. The third way is endocytosis, which moves into the cell and exocytosis, which moves out of the cell. These ways are used for large molecules. There is a place on the receptor membrane where receptor proteins can attach themselves and give information to the cell inside the membrane. There are only certain cells that the receptor proteins can communicate with.

Inside the Cell

The inside of the cell consists of “membrane bound and non-membrane bound structures” (Johnson)(pg. 63). Organelles are what the membrane bound ones are referred to as. A nucleus is the most apparent type of organelle. This is where DNA is stored. There is also an area referred to as the nucleolus where RNA is. Ribosomes are made from RNA and proteins and make certain proteins. The endoplasmic reticulum deals with the chemicals that are made by the cell. Endoplasmic reticulum has both rough and smooth parts. The rough part is for proteins and the smooth part for other macromolecules. Golgi apparatus is another part of the cell. This is where the chemicals are processed and made ready. Vesicles are where it is stored after it is ready and if necessary, transferred elsewhere. The organelle that provides energy to the cell is called the mitochondria. Glucose is one way the cell gets its energy. Other ways are fats and proteins.

Tissue

Cells group together according to their purpose and form tissue. There are four types of tissue. They are epithelial, connective, muscle, and nervous tissue.  Epithelial tissue is made of sheets of cells and cover up different parts of the body. Epithelia tissue has been grouped into three different categories based on what shape they are. The first group is squamous epithelium is made up of layers of cells that are flat. Cuboidal epithelium is made up of cube shaped cells. And columnar epithelium is made from tall rectangle cells. They are also grouped according to how many layers of cells are found in the tissue. Simple epithelium is a single layer of cells and is very thin so molecules are able to easily pass through. Stratified epithelium is when there is more than one layer of cells and so it offers protection to what it surrounds. Epithelial tissue has a basement membrane under it, which is made mostly from protein and is not cellular. Its job is to connect the epithelial tissue to the connective tissue that is under it. Or it may be connected to a cell junction whose job is to keep the cells together. Connective tissue keeps soft body organs from falling due to gravity. It also connects the different body parts, holds fat and makes the cells of blood. There are two kinds of connective tissue, fibrous and special connective tissue. Fibrous connective tissue gives strength, support and flexibility and links body parts. Specialized connective tissues are cartilage, bone, blood and adipose tissue.

                                                  

(Tissue Types)                                                                                                                                       

Muscle tissue are made from cells that are designed so that there can be some sort of movement. There are three muscle tissues, skeletal, cardiac and smooth. Skeletal muscle tissues are joined with tendons. Cardiac muscle tissue is located in the heart. Smooth muscle tissue encloses organs that can be emptied out such as the bladder and digestive tract and others. Nervous tissue is found in the brain, spinal cord and nerves and they transmit electrical impulses in the body.

Organs and organ systems

Organs are made from two or more tissue types and come together to perform a certain function. Sometimes they are found in cavities. Tissue membranes can be found lining the body cavities and in our skin. Tissue membranes are made from epithelial tissue and connective tissue. The four major kinds of tissue membrane are serous membranes, mucous membranes, synovial membranes, and cutaneous membranes.

The skin is an organ system as are hair, nails and glands. The outer layer of skin is called the epidermis and the inner layer is the dermis. The epidermis is made from epithelial tissue and the cells are continually replenished. The two kinds of cells that make the epidermis are keratinocytes and melanocytes. Keratinocytes are very strong cells and they are also waterproof. Melanocyte cells make melanin which is how our pigment is made. Melanin also protects from ultraviolet sun rays. The dermis is how skin is able to move and also gives it strength so it doesn’t tear easily.

Because of the different cells that come together to form tissues and then organs, it is very important for there to be homeostasis in the surrounding area. Homeostasis means the surrounding area stays the same, it is not changed. This is done by a negative feedback system.  

Works Cited

Baran, S. "8th Grade Science Class." September 2009. Horizon Middle School Science Classes. 2 Feburary 2012 <www.sbaran.net/scimeth/Scimethsteps.ipg>.

"DNA & RNA Art Print." n.d. art.com. 6 Febuary 2012 <www.art.com/products/p10287564-sa-i938012/dna-rna.htm>.

Johnson, Michael. Human Biology. Pearson Education, 2012.

Ophardt, Charles. "pH Scale." 2003. irtual Chembook. 6 February 2012 <http://www.elmhurswt.edu/~chm/vchembook/images2/184phdiagram.gif>.

Pearson Education. "BioCoach Activity." n.d. The Biology Place. 6 February 2012 <http://www.phschool.com/science/biology_place/biocoach/images/cells/allcell.jpg>.

Thomas Jefferson National Accelerator Facilty-Office of Science Education. "It's Elemental." n.d. Jefferson Lab. 5 February 2012 <http://education.jlab.org/itselemental/tableofelements.png>.

"Tissue Types." 22 May 2011. MedlinePlus. 8 Feburary 2012 <http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/index_clip_image001.jpg>.

Whittaker, Robert. "Cycling through the Food Web." n.d. Bigelow Laboratory. 2 February 2012 <http://www.bigelow.org/bacteria/whittaker.jpg>.