Sunday, February 12, 2012


I conducted three experiments using milk, juice and carrots. The objective was to see the change in milk after sitting in a warm, dark place in an open container for three days. The juice experiment objective was to see what would happen if 1/6 of a cup of cherry juice was added to two cups of three glasses at water, each at a different temperature. The objective of the carrot experiment was to see the outcome of the carrot size after sitting in a glass of salt water as opposed to a glass of fresh water for 24 hours.





Part 1: Milk



My hypothesis for the milk experiment: I think after the three days are over, the milk will turn a yellowish color from the bacteria after being at room temperature. Depending on how warm its storage place is (a microwave), I believe the milk may start to spoil and possibly have signs of becoming solid or having an unpleasant smell. The reason I believe this will happen is the popular outcome of spoiled milk, as it generally has a chunky consistency.



Process:

  1. Add ½ cup of milk to a shallow glass
  2. Notes, pictures, observations
  3. Store in a warm, dark place for three days.
  4. Observe (any) changes and take pictures of milk every day.



Notes and observations:

Day 1: The milk is fresh, so it has no noticeable abnormal characteristics.








Day 3:  The milk has a very slight but sure odor and the color seems a little bit darker, but it may have been the lighting.








I believe the milk didn't do much probably due to the temperature of its storing space, the microwave. The microwave, seemed like it would be a slightly higher temperature at first due to how much of an enclosed space it is with the rubber around the door to let air from getting in or out. However, it seemed to be closer to room temperature than anything. Had the microwave been warmer, or had I had a warmer space to store the milk, I think the results would have been different, and perhaps my hypothesis wouldn't have been so far from the truth.







Part 2: Juice







My hypothesis for the juice experiment: I think the juice when added to hot water will only become less concentrated, mixing with the water completely. When added to ice cold water, I believe it may separate at first impact because in the case of any drink with ice in it, the ice will melt, leaving a watery separation on the top of the drink until manually mixed in. When added to room temperature water, I believe that it will slightly separate, then mix completely.



Process:

  1. Pour one glass full of two cups of hot water.
  2. Pour 1/6 of a cup of cherry juice over the hot water.
  3. Notes, pictures, observations.
  4. Pour one glass full of two cups of ice cold water.
  5. Pour 1/6 of a cup of cherry juice over the cold water.
  6. Notes, pictures, observations
  7. Pour one glass full of two cups of room temperature water.
  8. Pour 1/6 of a cup of cherry juice over the room temperature water.
  9. Notes, pictures, observations.



Notes and Observations:

When added to hot water, the juice did mix in completely with the water.



When added to the cold water, the juice separated as it sunk to the bottom of the glass and left a layer of ice water at the top.



When added to the room temperature water, the effect was similar to the ice water, but the layer of water at the top was more noticeable as the juice sort of sunk to the bottom, leaving a cool cloudy effect for longer afterward than it did with the cold and hot water.






I was correct for the most part in all my hypotheses for the juice experiment with the exception of the room temperature juice and water. It was definitely a surprise to see how the juice clouded up in the water, then went toward the bottom of the cup.



Part 3: Carrot





My hypothesis for the carrot is that the carrot that is in the salt water will expand because salt retains water. I think the carrot in the fresh water might expand as well, but not as significantly as the salt in the salt water.





Process:

  1. Pour one cup full of two cups of salt water
  2. Pour one cup full of two cups of fresh water
  3. Cut carrot in half, measure each half
  4. Tie string around cut half of each carrot and place cut end down in each glass
  5. Leave for 24 hours
  6. Observe, take notes, pictures



Notes and Observations:



To my surprise, my saltwater carrot shrunk. The string wasn't as tight and the measurement was almost 1/3 of an inch smaller. Not a lot happened with my freshwater carrot, save for what looked almost like a centimeter or two of growth. The string was still very tight.

The saltwater carrot before the experiment:




The freshwater carrot before the experiment:



The saltwater carrot after the experiment:





The freshwater carrot after the experiment:





Clearly I was mislead about the salt most likely making the carrot retain the water around it. I pretty much figured not a whole lot would happen to the fresh water carrot, but the centimeters of growth were still a little shocking.



Unit One Compilation


Chapter One



Life:

All living things have a different molecular structure than nonliving things. They are composed of cells, have the ability to reproduce and procreate and maintain an internal equilibrium called homeostasis (requiring temperature regulation, internal blood flow, etc) . They require raw materials from the environment and energy from the sun to live. Living things also involve populations capable of evolving. They respond to their external environment to thrive.

Further Characteristics of life: Separated into groups

Domain Archaea:

Consists of single celled prokaryotes

The Kingdom Archaea


Domain Bacteria

Consists of single celled prokaryotes

The Kingdom Bacteria



Domain Eukarya

Consist of single or multicellular eukaryotes.

Kingdoms Animalia, Plantae, Fungi and Protista



*Prokaryotes contain no membrane-bound nucleus while eukaryotes do



-Humans are part of the Kingdom Animalia. They mammals, have vertibrates and are further considered “homo sapiens”, a type of primate meaning “thinking man”.



Characteristics of the Human

-Bipedalism- the ability to walk upright on two feet

-Opposable thumbs, have the ability to grab things between thumb and forefinger

-Large Brains for body size

-Language, both written and spoken







The Organization of Human Biology



Starts with molecules and atoms. Tissues are made of molecules and atoms. Organs consist of tissues. Organ systems contain the organs of the body. An organism (ex. Human) consists of the organ system. The organisms make up a population, where a community of populations is contained by an ecosystem, which belongs to the biosphere.





The Scientific Method:

Observe and generalize- observe and collect data

Hypothesis- Predict the Outcome

Predict the outcome- Use deductive reasoning

Experiment and observe- Conduct experiment

Modify Process and Repeat if necessary- Make necessary changes to make possible new outcome






Chapter Two



Chemistry is the study of matter. Matter consists of anything that has mass and occupies space. It is made up of elements



Structure of an Atom:

The atom contains a nucleus at the center, which is composed of protons (positive charge, have mass) and neutrons (neutral charge, has mass). Surrounding the nucleus is the shell, which consists of electrons (negative charge, has no mass)

Atoms:

-Have an atomic number, the number of protons. In an electrically neutral atom, the number of protons will equal the number of electrons.

-An atomic symbol, one or two letters. Generally the first two letters of the latin name for the element.

-An atomic mass- roughly equal to the number of protons plus the number of neutrons



Isotopes:

-Have the same atomic number, atomic mass

-Unstable isotopes are called radioisotopes, which give off energy in the form of radiation

-Radioisotopes can be useful for carbon dating, power supply for implants such as pacemakers, cancer treatment, and diagnostic imaging.



Energy is the capacity to do work. Potential energy is energy that is stored. Kinetic energy is energy in motion. Potential energy can transform into kinetic energy.



-Electrons-potential energy. The farther away from the nucleus the shell is, the more potential energy the electrons contain. Inner shells have less. Atoms are more stable when the outer shell is full of electrons with potential energy. Atoms will interact with other atoms to get more electrons to fill their outer shells if they need to.





Chemical bonds hold atoms together.

-Covalent bonds are strong. They are made when atoms share electrons. Electrons that are shared equally create non-polar covalent bonds. Electrons that are not shared equally create polar covalent bonds.



Ions:

An ion is an electronically charged atom or molecule. When an atom/molecule loses electrons, it makes a positively charged ion. So when an atom/molecule gains electrons, a negatively charged ion is formed. The ionic bond is what happens when oppositely charged ions bond. Ionic bonds are not as strong as covalent bonds, but not as weak as hydrogen bonds.





Hydrogen Bonds form between polar molecules. Polar molecules are electrically neutral, and they have polar bonds. Hydrogen bonds have a weaker bond.






Water:

Water can absorb and hold heat, so it helps regulate body temperature. The molecules are polar.

Solvents are liquids that substances dissolve in, solutes are dissolved substances.

-Polar molecules that are attracted to water are hydrophilic while nonpolar neutral molecules that don't do not dissolve in water are hydrophobic.



Acids, bases, and the pH Scale:

Acids increase hydrogen ions while bases lower them. The pH scale measures hydrogen concentration by determining whether the pH is at 7 (neutral), above it (acidic) or below it (alkaline). Buffers minimize change in pH and maintain it.



Carbon forms four covalent bonds and can form either single or double bonds. It also makes up 18% of the body.



Carbohydrates:

-Monosaccharides (glucose, fructose, glactose, ribose, deoxyribose).

They can be linked together (dehydration synthesis) to form disaccharides (sucrose, maltose, and lactose)

-Polysaccharides, thousands of monosaccharides joined together (starch, glycogen, cellulose)



Lipids:

Triglycerides:energy storage, fats and oils

Phospholipids:cell membrane

Steroids: carbon based structures, such as cholesterol and estrogen/testosterone



Proteins:

Amino acids

Enzymes (biological catalysts- speed up chemical reactions, but aren't altered)



DNA/RNA store genetic info, contain nucleotides (building blocks)



RNA- single stranded, nucleotide contains ribose, nitrogenous bases (adenine, guanine, cytosine, uracil)



ATP (adenosine triphosphate) is a nucleotide. It is the universal energy source.








Chapter Three



Cells:

Human cells are eukaryotic, so they have a plasma membrane, nucleus, cytoplasm (fluid in the membrane), and organelles. Cells are microscopic, they need to be seen with either a light microscope, transmission electron microscope, or scanning electron microscope. They have a high surface:volume ratio that helps the process of diffusion in that they can easily absorb nutrients easily and dispose of wastes. They can also stick together to form tissue.



The plasma membrane of a cell is selectively permeable, so some substances can go into and out of the cell while others cannot. It is a lipid bilayer composed of phospholipids, cholesterol to make it more rigid, proteins to help transport substances into and out of the cell, and carbohydrates.

During passive transport into and out of the membrane, the cell does not use its energy. The processes of diffusion and osmosis take place. The concentration gradient powers it, allowing diffusion through the lipid layer and protein channels. However, the cell must use energy during active transport. It uses a membrane protein to transport it and requires either ATP or another energy. During bulk transport, endocytosis (substances enter the cell) and exocytosis (substances leave the cell) take place. The only way for substances to get into and out of the cell is through information sent to the receptor sites on receptor proteins on the cell.



The Sodium Potassium Pump:

The sodium potassium pump maintains the cell volume, using ATP to expel 3 sodium ions for every 2 potassium ions in the cell. Increasing the cell volume means an increase in water in the cytoplasm, allowing more sodium inside the cell. Decreasing it means less water and expelling the excess sodium.



Tonicity is the relative concentration of solutes in two fluids. Isotonic tonicity requires the extracellular and intracellular ionic concentrations be equal so that the cells volume stays normal. Hypertonic tonicity will kill the cell. The extracellular ionic concentration exceeds the intracellular ionic concentration and water diffuses out of the cell, leaving it to shrivel up and die. Hypotonicity yields the opposite effect, wher the intracellular ionic concentration exceeds the extracellular ionic concentration and water will diffuse into the cell, bursting it.





Structure of a cell:





The nucleus holds genetic information and ultimately controls the cell.



Ribosomes float in the cytoplasm and bind to the outer surface of the endoplasmic reticulum. They synthesize proteins.



The endoplasmic reticulum (ER) can either have ribosomes (rough ER) and manufactures protein, or not have ribosomes (smooth ER) where it synthesizes lipids and packages the protiens.



The golgi apparatus refines the synthesized products and ships them to locations with in the cell or to the cell membrane.



There are several kinds of vesicles, such as endocytic, secretory and shipping and storage. Also, peroxisomes (detoxifying enzymes) and lysosomes (digestive enzymes)



The mitochondria, generates the cell. It generates ATP.



Fat, triglycerides store energy in animals.



Glycogen stores carbohydrates, also an energy storage.



Support and Movement of Cells:

Cytoskeleton for support

Cilia (short projections) used for movement and flagella (one long projected tail) for movement.

Centrioles



Anabolism, the building of cells may require energy or ATP. It requires enzymes and stores cell energy.

Catabolism breaks the molecules down, also requiring enzymes. But unlike anabolism, it may release energy and accesses energy storage. Glucose is used for energy in the cell. It generates ATP and provides the cell with energy using cellular respiration, consisting of glycolysis, the citric acid cycle and the electron transport system. Cellular respiration uses oxygen and produces carbon dioxide to make ATP. Other energy sources include glycogen, fats and proteins.







Chapter Four



Tissues are made up of cells.



Epithelial Tissues line body cavities and surfaces. There are simple (single layered) epithelial tissues, generally lining glands and respiratory, digestive and reproductive systems. There are also stratified (more than one layer) epithelial cells to provide protection. The basement membrane attaches the epithelial layer to other tissue layers. Junctions hold the cells of the epithelial tissue together. In cases of adhesion junctions and gap junctions, there is movement between the cells, but in tight junctions, nothing can move between the cells.

http://training.seer.cancer.gov/anatomy/cells_tissues_membranes/tissues/epithelial.html


Connective Tissue supports and cushions softer organs, and as its title suggests, connects. It also stores fat and produces blood cells. Fibrous connective tissue is elastic and strong. It includes fibroblasts, macrophages, lymphocytes and neutrophils. There are four types of fibrous connective tissue: lose, dense, elastic and reticular. Specialized connective tissues includes cartilage, bone, blood and adipose tissue



Muscle Tissue is flexible so it can be moved.

Skeletal muscle is voluntary and has more than one nucleus.

Cardiac and smooth muscle are involuntary and have only one nucleus.



Nervous Tissue transmits electrical impulses with its neuron.





Organs:

Organs are made up of tissue

Organ systems are groups of organs that perform the same function, such as digestive, respiratory, cardiac, etc.



The anterior body cavity is comprised of the thoracic and abdominal cavities while the posterior cavity contains the cranial and spinal cavity. Serous membranes line these cavities. Serous membranes reduce friction between organs.

Mucous membranes lubricates surfaces of organs

Synovial membranes line spaces in between moving joints

Cutaneous membrane is the skin





The skin:

Prevents dehydration, protects the body, regulates body temperature, makes vitamin D and provides the body with sensation to the touch.



The epidermis is the outer layer of the skin, consisting of stratified squamous epithelial cells. The dermis, right below the epidermis supports tissues. The accessory structures of the dermis include hair shafts and follicles, smooth muscle (attached to the hair follicle), oil/sebaceous glands to moisten the skin, sweat glands, blood vessels and sensory nerve endings.



Homeostasis:

The negative feedback control system helps maintain homeostasis using body temperature (controlled variable), sensors (the thermometers), the control center (the hypothalamus), and effectors (blood vessels, sweat glands, skeletal muscles).