Compendium Review Chapters 1-4
I.Exploring life and Science
A.Characteristics of Life
B.How humans are related to Other Animals
C.Seeing Science as a Process
D.Understanding Scientific Study
II.Chemistry of Life
A.From Atoms to Molecules
B.Water and other Living Things
C.Molecules of Life
1.carbohydrates
2.lipids
3.proteins
4.nucleic acids
III. Cell Structure and Function
A.What is a cell?
B.How are cells organized?
C.Parts of a cell
1.plasma membrane
2. nucleus
3.ribosomes
4.endoplasmic reticulum
5.Golgi apparatus
6.lysosomes
D.Cytoskeleton and Cell Movement
E.Mitochondria and Cellular Metabolism
IV. Organization and Regulation of Body Systems
A.Types of Tissues
1.connective
2.muscular
3.nervous
4.epithelial
B.Cell Junctions
C.Skin
D.Organ Systems
E.Homeostasis
Life has seven basic characteristics. Life is organized, from atoms to the biosphere. Ranging from smallest to largest there is the atom, followed by molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, and biosphere. All living things take materials and energy from the environment. Humans and animals acquire energy through the consumption of food. Most living things convert energy into motion. All living things reproduce, creating a copy of the parents. The genes in DNA molecules pass on hereditary info. All living things grow and develop, increasing in size and the number of cells. Living things also share the quality of being homeostatic. Organ systems maintain homeostasis in living things. “For example, human body temperature normally fluctuates slightly between 36.5 degrees Celsius and 37.5 degrees Celsius (Mader, pg. 4)” All living things also respond to stimuli. This can even be noticed in plants which will lean toward their source of light. Finally, all living things have an evolutionary history. Species have changed throughout time to adapt to their environment.
Humans are related to other animals. There are three domains of life.
Archae and bacteria both lack a nucleus. The third domain, is the eukarya, which have a nucleus and are divided into 4 kingdoms : protista (with approximately 250, 000 species), fungi (100,000 species), plantae (250,000 species), and animalia (1,000,000 species). Humans, of course, belong to the kingdom animalia. All humans have a cultural heritage. Activities and products pass on through generations. Humans are important members of the biosphere, but also pose a threat to it as well
Science has a very defined process. Scientists use a method called the scientific method to come up with scientific theories.
The steps to the scientific method are as follows :
1.observation – the researcher makes an observation about a process or event
2.hypothesis – the researcher formulates an idea as to what will happen when a certain situation occurs
3.experiment and observations – the researcher tests the hypotheses
4.conclusion – the researcher comes to a conclusion based on results of the experiment and observations
5.scientific theory – if there is enough evidence to support it, the reasearcher’s discovery becomes a scientific theory
We often use the scientific method to discover things on our own, without even realizing it. For example, when I was reading this chapter more than a week ago, I noticed my not quite 2 year old daughter using it to make a discovery. Here is how she used it.
1.observation – She was sitting on her potty chair, and I was standing in the bathroom with her. She covered her eyes, and remarked, “It’s dark.”
2. hypothesis - She then decided in her mind that when it’s dark she can’t see things.
3. experiment - She sat there for a solid five minutes covering her eyes saying, “It’s dark…no see mama”, then uncovering her eyes saying , “it’s bright – oh, there mama is”. She did this repeatedly (a good scientist always conducts their experiment more than once).
4.conclusion – after five minutes of this repeated behavior, she proudly announced “When cover eyes, it’s dark. I no see mama.”
Experiments are often done by performing a controlled study. In a controlled study, the only things that change are the experimental variables. For example, when testing the effectiveness of a medicine, the control group are just given a placebo. The test group are given the actual medicine. In a completely objective study, a double blind experiment is performed where neither the patient or the examiner know which group is given what.
Scientific journals are highly regarded as the most trustworthy source of scientific information. They come straight from the researcher instead of being passed on by a third, or even fourth, party. They go through a thorough review process before being published. If you look to the internet for scientific information, your best bet are sites ending in .edu, .gov, and .org.
Elements are a basic building block of nature. There are 92 known elements. They are known by name and symbol. For example, Oxygen is O, and Iron is Fe.
Atoms are the smallest unit of life. They have protons, which have a positive charge, and neutrons, which are neutral, in the nucleus. Electrons, with a negative charge, orbit in rings around the nucleus. All elements have an atomic number which tells how many protons and electrons that element has. The atomic mass is equal to the number of neutrons.
Isotopes differ in mass from the original element. Some of these can be radioactive, and are called radioisotopes. If they are used in low levels, they can be used as tracers to be injected into the body to help doctors find what is wrong with organs and tissues. In high levels, radiation can harm cells, damage DNA, or even cause cancer. Scientists have been able,
however, to control the radiation, and have it “introduced into the body in a way that allows radiation to destroy only cancer cells, with little risk to the rest of the body (Mader, og.21a).”
Atoms bond together to form molecules. If the atoms that bond together are different, they form something called a compound. There are two main types of bonding that can occur. These are ionic and covalent. In ionic bonding, atoms give up or take on electrons as they bond to one another. In covalent bonding, the atoms share electrons.
Water is the most abundant thing found in living organisms. It makes up 60 to 70% of total body weight. Water is formed by hydrogen bonds which occur when a covalently bonded hydrogen is only slightly positive and attracts to a negative atom some distance away.
There are six important properties of water. Water is a liquid when it is at room temperature. This gives it several uses, such as drinking, cooking, and bathing. The temperature of water when it is in liquid form, rises and falls very slowly in order to prevent sudden changes. Water keeps the body form overheating because it has a high heat of vaporization. Frozen water is less dense than liquid water, which allows for ice to float on water. This is why aquatic animals have a better chance of surviving cold weather – the ice forms on the surface of the water, allowing them to move freely in the slightly warmer water underneath. Water molecules are cohesive which allows liquids to fill vessels. Water is a solvent for polar molecules and allows chemical reactions to occur. “Ions and molecules that interact with water are said to be hydrophilic. Nonionized and nonpolar molecules that do not interact with water are said to be hydrophobic (Mader, pg25).”
Acids have a high number of hydrogen ions. Some acids that are most commonly known are lemon juice, and coffee. Bases have a low number of hydrogen ions. The most commonly known of these are milk of magnesia, and ammonia. Acids and bases are measured according to the pH scale which is a system of numbers, 0 being the most acidic and 14 being the most basic. 7 is neutral, and includes pure water and tears.
pH scale
There are four molecules of life. These are carbohydrates, lipids, proteins, and nucleic acids. Carbohydrate molecules look like this : H-C-OH. There are monosaccharides and disaccharides which are considered simple carbs These are when the number of carbon atoms in a carbohydrate are low. Complex carbohydrates, or polysachharides, include starch, glycogen, and cellulose. High fiber carbohydrates can be beneficial to the diet. Lipids are most commonly known as fats, which come from animals, and oils, which come from plants. Emulsifiers can cause fats to mix with waters. Saturated fats have no double bonds between the carbon atoms. Unsaturated fats have double bonds between the carbon atoms. Trans-fats are partially hydrogenated which means that not all bonds are saturated with hydrogen molecules. Steroids are a special type of lipid that differ greatly in structure from fats. Proteins serve many important functions in humans. Proteins such as keratin and collagen provide structural support. They produce enzymes which speed chemical reactions in cells. Channel and carrier proteins exist in the plasma membrane and allow substances to enter and exit the cells. Antibodies are a special type of protein that provide defense. Hormones are a type of regulatory protein. Actin and myosin are contractile proteins that cause muscle contraction, allowing movement. Protein structures have at least three levels of structure…the primary which is linear, the secondary which is an alpha helix or a pleated sheet, and the tertiary, which is three dimensional. Some also have a fourth level, or quaternary structure. There are two types of nucleic acids. These are DNA and RNA. DNA molecules contain many genes which specify the sequence of amino acids. The structure of DNA and RNA differ in their nucleotides. DNA contains the sugar deoxyribose and RNA contains ribose. There are four types of bases in DNA - adenine, thymine, guanine, and cytosine. In RNA, the base uracil replaces thymine. ATP, or adenosine triphosphate , is an energy carrier in cells
animal cell
The cell theory states that a cell is the basic unit of life and that all living things are made up of cells. It is also known that new cells arise only from preexisting cells. Cells have an evolutionary history. Prokaryotic cells, which had no nucleus, were the first cells. Eukaryotic cells evolved from archaea and have a nucleus, and also an endomembrane system. Eukaryotic cells also have a plasma membrane, cytoplasm, and organelles. The plasma membrane is a phospholipid bilayer which is liquid at room temperature. Its main function is to keep cells intact. It is selectively permeable, which means that it only allows certain substances to pass through. There are several ways in which substances are able to cross the plasma membrane. Diffusion is one of them. It is the random movement of molecules from an area of higher concentration to an area of lower concentration. Osmosis is the diffusion of water across a plasma membrane. The three types of osmosis are isotonic, hypotonic, and hypertonic. In facilitated transport, molecules are transported at a higher rate. In acttive transport, molecules move contrary to normal. "During endocytosis, a portion of the plasma membrane invaginates, or forms a pouch, to envelop a substance and fluid. (Mader, p.48)" Exocytosis occurs as a vesicle fuses with the plasma membrane.
The nucleus is the core of the cell. It stores the genetic info and contains DNA and RNA. It also has chromatin which contains DNA and protein. The nucleus is separated from cytoplasm by a nuclear envelope and endoplasmic reticulum. The ribosomes house the protein and rRNA. The endomembrane system is composed of several parts. There is both smooth and rough endoplasmic reticulum, the golgi apparatus, and the lysosomes. The cytoskeleton is made up of large microtubules. It helps maintain a cell's shape and either anchors the organelles or
assists their movement. Organelles move either by cilia or flagella.
Mitochondria are the powerhouses of the cell. The process of producing ATP is known as cellular respiration. Respiration is a component of metabolism. Enzymes speed up chemical reactions and coenzymes are nonprotein molecules that assist the activity of an enzyme. After glucose and oxygen are transported to cells by the blood, cellular respiration occurs. The main function of cellular respiration is to break down glucose to carbon dioxide and water. The three pathways involved in the breakdown of glucose are glycolysis, which literally means sugar splitting, citric acid cycle, which completes the break down of glucose, and the electron transport chain which accepts two electrons and passes them on to the next carrier, Fermentation is an anaerobic process which gives the body a short energy boost. However, it promotes the buildup of lactate which is toxic to cells and causes muscle cramps and fatigue.
There are four main types of tissues : connective, muscular, nervous, and epithelial.
Four types of tissue
Connective tissues by themselves, have several different types...all with the main function of connecitng and supporting. Fibers are one type of connective tissues and these include collagen, reticular, and elastic. Fibrous connective tissue ca be loose, adipose, or dense (found in tendons and ligaments). Supportive connective tissue is cartiage and can be hyaline (found in the nose), elastic (outer ear), and fibrocartiilage (disks). Bone is also a type of connective tissue and can be compact or spongy. Many people would not think of blood as a tissue, but it is known as a fluid connective tissue, as is lymph. Muscular tissues include skeletal (which is voluntary), smooth (visceral), and cardiac (found in the heart). Nervous tissue communicates and consists fo nerve cells called neurons and neuroglia. Epithelial tissue protects. Simple epithelial tissue can be squamous, cuboidal, or columnar. Pseudostratified columnar appears to be layered. In transitional epithelial tissue, tissue changes in response to tension. Stratified epithelia have many layers of cells piled on top of one another. Glandular epithelia secretes a product. There are three types of cell junctions which help a tissue perform its particular function : tight, adhesion, and gap. The skin of our bodies is known as our integumentary system. It's regions include the epidermis, and the dermis. The subcutaneous layer is beneath the dermis and is not considered a part of skin. It is a common site for injections. There are several parts of our body that are considered accessory organs of the skin. These include nails, hair follicles, oil glands, and sweat glands.
There are many other organ systems in our body that are not delved into in Chapter 4. These include the cardiovascular, the lymphatic and immune, the digestive, the respiratory, the urinary, the skeletal, the muscular, the nervous, the endocrine, and the reproductive.
Homeostasis helps to maintain relative constancy of the internal environment by adjusting physiological processes. Negative feedback keeps the variable close to a set point. Positive feedback brings about an ever greater change.
Aside from using the textbook for this information I also used the following websites
http://waynesword.palomar.edu/trfeb98.htm
http://scienceblogs.com/clock/2007/01/current_biological_diversity.php
http://images.google.com/imgres?imgurl=http://www.indiana.edu/~geol116/week1/meth%2520copy.jpg&imgrefurl=http://www.indiana.edu/~geol116/week1/week1.html&h=900&w=2100&sz=296&hl=en&start=13&sig2=TCF4zoZl1cLrAmHZogAnOA&um=1&usg=__Yl66ldyeT1sp9eXodRWSTEPmpDw=&tbnid=ShhXAxm-MA41qM:&tbnh=64&tbnw=150&ei=nEvHSNjqHo6OsQOYj7HUDw&prev=/images%3Fq%3Dscientific%2Bmethod%26um%3D1%26hl%3Den%26sa%3DN
http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/PH_scale.png/639px-PH_scale.png
http://www.uvm.edu/~inquiryb/webquest/fa06/mvogenbe/Animal-Cell.jpg
http://apps.uwhealth.org/health/adam/graphics/images/en/8682.jpg
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