Compendium of Chapters 1-4


Chpt 1
1.1 The Characteristics of life

In the vastness of our world there is a daunting array of wildlife. Animals that vary so much, they appear to be unrelated. However, we learn in the Characteristics of Life, that all animals have evolved from a single cell. There are qualities that all share in the living and propagation of their lives. They are as follows:
· Have order from atoms and cells to the community, ecosystem and biosphere (you know, that great big cell. . .)
· Need energy
· Reproduce
· Grow
· Maintain homeostasis – are internally balanced
· Respond to stimuli – within and externally
· Adapt to their environment and evolve

http://faculty.mccfl.edu/rizkf/OCE1001/Images/benthicorg2.jpg&imgref

1.2 Humans are Related to Other Animals

Humans are classified in the domain Eukarya and kingdom Animalia. We are vertebrates who are mammalian. Other mammals would be dogs, cats, apes, cows, etc.

1.3 Science as a Process

Scientists use a method universally to investigate the world and beyond. Initally, observations are made of the subject of interest. Data is gathered and recorded. From that information, one would formulate an idea or hypothesis regarding an aspect of what was observed. More testing is done to test whether or not this theory is potentially viable. Conclusions are drawn from the testing and other accumulated facts and observations. From that, a scientific theory is born.

Controlled studies help in accumulating information. In this type of testing, groups of subjects are tested in precise, yet different ways. This enables the researchers to conclude what would transpire without intervention, with intervention, or even with another or multiple different approaches. The investigators then draw their conclusions from the data obtained and they are usually published in a scientific publication. Studies submitted for inclusion are reviewed by peers prior to becoming published. It is not uncommon for a study to spur another.

1.4 Making sense of a scientific study

An example of a scientific graph

http://www.relexsoftware.com/products/images/screens/xp_predgraph.gif&imgrefurl

As important as it is to provide studies, the interpretation of that data and conclusions is vitally important. One must bear in mind the methodology utilized to obtain the data; whether anecdotal, statistical or derived from a long controlled study. We must also evaluate whether the conclusion is a valid interpretation of the data collected.

1.5 Science and social responsibility

There are multiple issues involving the advancement of knowledge and application of such with the means we now have through technology. Nuclear power and the nuclear bomb, rearranging genetic make-up of certain plants or people to produce healthier alternatives, all have consequences. When we alter one part of the ecosystem, it can’t help but to impact another. Through the food chain or through genetics, some other living thing will be affected by our manipulation. We have a responsibility to see that our discoveries benefit not just humans, but the rest of our world as well.

Chapter 2


2.1 From Atoms to Molecules

Atoms used to be thought to be the smallest unit of matter. In fact, smaller parts comprise atoms. The center of an atom consists of protons (a positive charge) and neutrons (a neutral charge). Orbiting around this center are electrons which have negative charges. This unit in its entirety is called an atom which demonstrates the chemical and physical properties of the pure matter, called elements; matter that cannot be reduced or broken down by any chemical means. When atoms bind to like atoms, these elements are formed. Our bodies are made primarily up of 4 elements, carbon, oxygen, hydrogen, and nitrogen.


Some elements have differing numbers of neutrons. The more neutrons present in the nucleus, the more unstable it becomes, thus causing it to give off radiation. This occurs naturally in our environment. Isotopes behave the same as their normal counterparts, but release energy as they decay and they do that more rapidly. In the medical field, these isotopes can be utilized to image different organs or cancers after being introduced into the body. Exposures to higher levels of radiation can kill cells, thereby people on a grand scale. As an example, 70,000 people died the day the atom bomb was deployed on Hiroshima, the five year toll of radiation-caused deaths was estimated to be as high as 200,000.
Radiation burns from Hiroshima
(http://www.cfo.doe.gov/me70/manhattan/hiroshima.htm)

Atoms bind together to form molecules, the next larger unit of matter. They form bonds in varying ways. In ionic binding, an atom will give an electron to the orbit of another atom. One will have a positive charge, the other a negative charge and as we well know, opposites attract. Covalent bonding is when two or three electrons are shared by a number of atoms which keeps these together.

2.2 Water and Living Things

Water is fundamental to life and has interesting qualities of it’s own. Water is comprised of 2 hydrgen atoms and one oxygen atom. Since the hydrogen carry a negative charge and the oxygen a positive, the molecule is polarized (negative on one end and positive on the other). This polarization loosely holds several water molecules together giving water some unique properties.
* It is liquid at a comfortable temperature allowing us to injest and bathe in it
* It buffers temperature changes because it reacts slowly to them
* When frozen, water will float on itself, insulating whatever is beneath
* Water doesn’t vaporize until very hot – keeping us cool
* Water is held together by polarization and will fill vessels – the ones we drink from and the ones coursing through our bodies
* Water helps separate other charged (polarized molecules and is useful for dissolving some chemicals (hydrophilic). Not all matter will dissolve or interact with water (hydrophobic).
A drop of water on a nano-structured hydrophobic surface
http://web.mit.edu/pccs/research/images/p_nanosurfaces.jpg
Acidic and base solutions are formed when molecules dissociate in water. When molecules dissolve, releasing hydrogen ions (H+), the solution becomes acidic. Stomach acid, soda, beer, coffee, lemons are examples of these. Base solutions occur when substances release hydroxide ions (OH-) or assimilate hydrogen ions. Sodium hydroxide, oven cleaner and ammonia are examples of these. It goes without saying that you should never ingest a strong acid or base solution. The pH scale measures how acidic or basic a solution. 0 is the most acidic (hydrochloric acid) and 14 to most basic (sodium hydroxide). Water is exactly 7 and human blood when healthy measures at 7.4. Living things have buffering systems to maintain a healthy pH, but these systems can become overtaxed when bombarded with abnormal solutions or foods.

2.3 Molecules of Life

There are four categories of carbon-based molecules (organic) called macromolecules. These consist of smaller subunits. They are proteins, lipids, carbohydrates, and nucleic acids (DNA/RNA).

2.4 Carbohydrates
Carbohydrate molecules provide all living things with short-term energy storage. There are two types:
Simple: (a monosaccharide has 3-7 carbon atoms), glucose, fructose from fruits, and lactose in dairy.
A disaccharide is two monosaccharides joined by a dehydration reaction (maltose).
Complex: polysaccharides comprised of many glucose units (as many as millions of atoms), starches and glycogen. These are stored in the liver prompted by insulin released from the pancreas. The liver releases glucose to maintain a healthy blood glucose concentration.

In-n-Out Masterpiece macromolecules well-represented

http://www.shroomery.org/forums/files/06-04/850536514-In-n-Out-100x100-served_closeup.jpg
Cellulose is also a polysaccharide and is joined together differently causing it to be eliminated from our system as fiber.

2.5 Lipids

Lipids are energy-dense molecules. They are hydrophobic (don’t dissolve in water), have little oxygen and are mostly carbon and hydrogen.
Fats and oils comprise the lipids. Fats are animal (solid at room temperature) and oils are of plant origin (liquid at room temperature). Fats help the body in different ways; it insulates and protects as well as stores energy for future use. Oils are unsaturated (favorable) and fats are saturated (unfavorable) with hydrogen atoms and are harmful encouraging formation of plaque in our arteries. Trans-fats are even more detrimental and companies have recently discontinued or reduced their usage.
Membranes consist of phospholipids – semi-polarized molecules which align their heads towards water and the tails are hydrophobic.
Steroids are lipids derived from cholesterol. From these, sex hormones are derived, testosterone for men and estrogen for women.

2.6 Proteins

Multitasking is what proteins do best. They support and provide functions in many different ways.
Here’s a few:
Antibodies – fight infection
Contractile – movement
Enzymes – catalyst – will help break down food (Pepsin, Lactose)
Hormones – work as messengers (insulin, oxytocin)
Sturctural – hair and ligaments, beaks and horns
Storage – for amino acids (ovalbumin in egg whites)
Transport – carries nutrients to other parts of the body (http://biology.about.com/od/molecularbiology/a/aa101904a.htm)
Proteins are structured differently in order to accomplish their function – one type does not necessarily resemble another. If their shape should be altered, they cannot perform their tasks. This can occur from heat or chemicals.
Proteins are comprised of amino acids, they are the subunits of proteins. These join together via peptide bonds to form various shapes which are accomplished at 4 levels. Primary is a simple chain, secondary becomes a spiral or then a folded or pleated sheet. Tertiary is a 3-d structure, which can join another, becoming a quaternary structure. Hemoglobin is one example of this type of complex protein.

2.7 Nucleic Acids

These were discovered on the surface of the nucleus of cells. DNA has information (genes) that affects reproduction. RNA transmits that information regarding the sequence of genetic materials. It is reported that each human cell contains six feet of DNA. These long strands are a series of nucleotides which have a definite order referred to as the human genome. This knowledge opens other advancements in gene therapy and the ability to cure many illnesses.

http://news.bbc.co.uk/furniture/in_depth/sci_tech/2000/human_genome/dna_infograph1.gif&imgrefurl
Nucleotides also help with metabolizing carbohydrates and proteins. Glucose is broken down into ATP making it usable within the cells.

Chapter 3 Cell Structure and Function

3.1 What is a cell?

A cell is the smallest unit of life. Molecules form to make cells which reproduce, grow, respond to their environment and exhibit the rest of the qualities of life. A single cell can be a living independent organism. Human beings average 10 trillion cells. Placed end to end they would stretch around the earth 47 times. The largest human cell is the egg and measures about the diameter of a human hair. The smallest, a sperm cell produced by the male, is one/tenth that size. (Cells of the Human Body © Prepared by Jim Cornish, Gander, Newfoundland, Canada, 2003. pg1) Eggs that you eat for breakfast are a single cell.

http://adsoftheworld.com/files/images/eggs.preview.jpg&imgrefurl

A large cell is not very efficient for transporting nutrients due to the decreased surface area when compared to the volume of the cell. Soon after fertilization, the cell quickly divides within the shell multiple times thereby increasing the surface area and decreasing the distance substances must travel.
Because of the minute size of cells, observing them requires special equipment. Microscopes have evolved into very sophisticated machinery since initially invented in the 1600’s. Light microscopes are the most common and affordable means of magnifying cells and can magnify up to2000X. Different types of light and stains enhance our ability to differentiate parts of the object. Transmission electron microscopes utilize electrons in a vacuum environment and a viewing screen. They have the capability of magnifying objects up to 50,000X. Final images usually need to be colored to enhance the objects pictured.

3.2 How Cells are Organized

Cells originated as prokaryotic. These are very simple units devoid of a nucleus and many of the other structures present in eukaryotic cells. Bacteria are prokaryotic cells. Eukaryotic cells are the basis of plant and animal life. They are much larger and more complex than the prokaryotic. All cells have membranes to filter which substances enter or leave the cell. An interesting theory is that eukaryotic cells may have developed some of their organelles by engulfing prokaryotic cells.

3.3 The Plasma Membrane and How Substances Cross It

Cellular membranes comprised of phospholipids, maintains the health of the cell by allowing and disallowing substances to cross into or out of the cell. Some transport is passive, influenced by higher or lower concentrations inside/outside the cell wall or proteins also passively accept certain substances into the cell thereby avoiding passing through the membrane. Proteins embedded in the membrane also mark the cell for identification and respond to signals from outside the cell.
Active transport requires energy and protein pumps to force the movement of needed substances across the membrane. Certain electrolytes are transported this way. Sometimes the cell wall will develop pockets that envelope substances and move them in and out of the cell (endocytosis and exocytosis.

3.4 The Nucleus and the Production of Proteins

The largest organelle is the nucleus which maintains the genetic integrity and regulates the cell, specifying its proteins. DNA (genetic material) and RNA (messengers and facilitators of the development of certain proteins within the cell) are located in the nucleus. The nucleus is enveloped in its own membrane (endomembrane) surrounded by nucleoplasm. Inside this envelope there are smaller subnuclear bodies which work together to develop Kiwi nucleus and process lipids and proteins.

www.york.ac.uk/res/sots/activities/diydna.htm

3.5 The Cytoskeleton and Cell Movement

Formed as in intricate web within the walls of the cell, is the cytoskeleton – fibers comprised of microtubules which help to shape the cell and placement or movement of the organelles within it.
Some microtubules are formed into cilia, small tail-like which extend a short distance from the cell. These can be for transport of debri or are capable of moving eggs along the oviduct. Flagella tails are approximately 20X longer and propel sperm.

3.6 Mitochondria and Cellular Metabolism

The organelle, mitochondria, is where glucose is converted to ATP providing usable energy. It is theorized that prokaryotes are the precursor of mitochondria It’s odd to think that cells breathe, but the mitochondria use oxygen for this process and release carbon dioxide and this process is called cellular respiration. Metabolism is the process of all chemical reactions needed to maintain life, including cellular respiration. Enzymes must be in order and all present for this to happen. Certain enzymes react only to certain substrates. For example, lactose can only be digested with the presence of lactase. If lactase is missing, you are lactose intolerant. Coenzymes assist enzymatic activity and are often derived from vitamins.

Cellular respiration requires the following to complete the process:
Glycolysis –the splitting of glucose. This process does not require oxygen (anaerobic).
Citric acid cycle – completes the breakdown of glucose and facilitates the removal of byproducts (hydrogen and electrons) via the electron transport chain. This requires oxygen (aerobic).
ATP is the end result (usable energy) and each cell produces its own.
Fermentation is what occurs when oxygen is not available. This results in a buildup of lactate, causing sore muscles. This can be a fatal state if our bodies don’t revert back to normal cellular respiration.

Chapter 4 Organization and Regulation of Body Systems

4.1 Types of Tissues

The material formed from like cells is called tissue. There are 4 types of tissue in the human body, connective, muscular, nervous, and epithelial. Different types of tissues can comprise an organ

http://fig.cox.miami.edu/~cmallery/150/physiol/sf38x5.jpg
and various organs that work together to perform a function, are a system.

4.2 Connective Tissue Connects and Supports

There are different forms of connective tissue, some elastic, others very dense or hard. Areolar (loose) tissue supports organs and skin. Adipse (fat) tissue supports and insulates organs and is also used for long term storage of energy. Fibrous (dense) tissue comprised tendons and ligaments needs to be strong enough to keep muscles and bones attached during exertion.
Cartilages are tissues that are provide a smooth surface for joints, provide flexibility for ears and the tips of our noses and are a cushion between certain bones elsewhere. There are three types of cartilage, Hyaline, elastic, and fibrocartilage.
Bone is the hardest form of connective tissue, providing support and protection of our entire mass. Its ground substance is largely comprised of calcium supported by protein fibers. Long bones have compact matter. Spongy bone provides strength at points of higher stress and fills irregular spaces.
Blood and lymph are also quantified as connective tissues. Blood has many components, red blood cells carrying oxygen and food for our body’s cells, white blood cells which fight infection, and platelets that help to clot vessels when needed. Lymph fluid runs throughout the body carrying excess fluid and dissolved matter from tissues.

4.3 Muscular Tissue Moves the Body

Muscular tissue is why we can move and certain organs are able to carry out their functions.
There are 3 types of muscle in our bodies. Some require thought or will to move (skeletal). These muscles only move when we want them to or sometimes will shiver to produce heat. Seizure or nervous disorders can also affect skeletal muscle causing tremors or convulsions. Smooth muscle is involuntary, meaning that you don’t think about moving it. Your intestines are an example of smooth muscle. They contract all day and night moving your waste matter along as it is being processed. It is also present in other organs and blood vessels. Cardiac muscle is comprised of individual beating cells. These harmonize when bound together and allow
themselves to be paced in unison.

4.4 Nervous Tissue Communicates

There is a network throughout the body that communicates signals between receptors and the brain or spinal cord. The dendrites collect information and send the impulse along the axon across the synapse (gap) to the next neuron. The response is then transmitted back from the brain or spinal cord to orchestrate the required reaction.

http://www.morphonix.com/software/education/science/brain/game/specimens/neuron_parts.html
Neuroglia (glia) are cells that support and protect neurons. The following four neuroglia are found in the CNS:
Astrocytes have numerous processes that give the cell a star-shaped appearance. Astrocytes maintain the ion balance around neurons and control the exchange of materials between blood vessels and neurons.
Oligodendrocytes have fewer processes than astrocytes. They wrap these cytoplasmic processes around neurons to create an insulating barrier called a myelin sheath.
Microglia are phagocytic macrophages that provide a protective function by engulfing microorganisms and cellular debris.
Ependymal cells line the fluid-filled cavities of the brain and spinal cord. Many are ciliated.

Two kinds of neuroglia are found in PNS:
Schwann cells (neurolemmocytes) wrap around axons to produce an insulating myelin sheath. Schwann cells provide the same function in the PNS as oligodendrocytes provide in the CNS.
Satellite cells are located in ganglia where they surround the cell bodies of neurons. (CliffsNotes.com. Neuroglia. 11 Feb 2008 . )

4.5 Epithelial Tissue Protects Epithelium Types (From J. Parks, Cornell University)

Epithelial tissue lines surfaces and body cavities.

They are as follows:
Simple Epithelia
Squamous – lines the lungs and blood vessels. O2 and CO2, food and waste are exchanged across this barrier http://www.wisc.edu/ansci_repro/lab/lab3/histology/epithelium_gy/epithelium_types.jpg&imgrefurl Cuboidal Epithelium – cubed shaped. They absorb and secrete and are located on glands, kidney tubules, thyroid gland and ducts
Columnar epithelium – shaped like pillars with nucleus near base. May line stomach or intestines and will absorb nutrients. Some sensory- oriented columnar cells are located in the ears, nose and tongue.
Pseudostratified Columnar Epithelium – seems stratified, but is irregular in the placement of nuclei. This can be located in the windpipe and is ciliated, helping to rid the body of mucus and foreign matter.
Stratified Epithelia-layered coverings consisting of multiple layers of cells on top of one another. This is protective in nature found in the nose, mouth, esophagus, anal canal, vagina and cervix.
Glandular Epithelia – secretes substances onto surface (sweat gland) or cavity (exocrine) or internally (endocrine) glands.

4.6 Cell Junctions
Three types
Tight – no leakage between cells, located in stomach, kidneys and bladder.
Adhesion – stretchy, will stretch to accommodate movement.
Gap – Allows for differentiation of cells, cardiac muscle.

4.7 Integumentary System

The skin is the integumentary system because it is comprised of several organs working together. The average adult has 19.5 square feet. The skin protects, contains, and maintains. It prevents loss of fluids and responds to changes in order to regulate our temperature.
Regions of the skin:
The epidermis is the outermost layer and is stratified and is shed. There are Langerhans (macrophages) that fight disease and melanocytes producing melanin that colors our skin.
The dermis holds the skin together and stretches to accommodate movement. Blood vessels in the dermis are affected by heat, cold and emotions, sometimes causing that embarrassing blush. Also part of this system are nails, oil glands, hair follicles and sweat glands.

4.8 Organ Systems

There are 11 organ systems. Here is a list of them and their function.


National Library of Medicine (Content source); Emily Monosson (Topic Editor). 2007. "Organ systems and organs." In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth October 6, 2006; Last revised February 8, 2007; Retrieved February 11, 2008]. <http://www.eoearth.org/article/Organ_systems_and_organs>

Our brain and spinal cord are in the Cranial and Vertebral cavities. These together become the dorsal cavity. Our thoracic, abdominal, and pelvic cavities combined are the ventral cavity. We have membranes that line our organs, cavities, and whatnot. They are as follows:
Mucous: Produces (you guessed it) mucous (from goblet cells) which protects from germy invaders. Located in the respiratory, digestive, urinary, and reproductive systems.
Serous: Produces serous fluid which lubricates and supports organs and membranes in the thoracic and abdominal cavity.
Synovial: Secretes synovial fluid for lubrication in a joint.
Meninges: Located in the dorsal cavity. Their function is to protect the brain and spinal cord.

4.9 Homeostasis

Homeostasis is the process by which our bodies maintain a suitable environment for life. This involves multiple internal approaches. There are two parts of our body that carry out these functions – the blood and tissue fluid.

These are the systems involved in homeostasis and how they achieve it:

http://faculty.southwest.tn.edu/rburkett/urinar31.jpg

Negative feedback is the process whereby one system communicates with the control center of that particular task to make a correction in errant homeostasis. Say you’re too hot, then the nervous system signals that and you begin to sweat to cool off.
Positive feedback encourages a process and gives it more dynamic. If a woman is in labor, the signals of that event cause a hormone to be released which, in turn, will cause stronger uterine contractions.quires oxygen (aerobic).