The Science of Life

Jacqueline Basallo

INTRODUCTION

a. EXPLAIN WHY YOU ARE ALREADY A SCIENTIST

Science is the state of knowledge; knowledge as a system testing the truths of accepted laws through the scientific method. Daily, we interact with living organisms, matter, atoms, compounds, et cetera, all which arose from theories which were once tested. Unknowingly, we put the scientific method to work to solve menial problems in everyday life and for this reason, I, and every human being, is already a scientist.

b. DESCRIBE CAREER GOAL

Futuristically thinking, I aspire to some day become a successful architect. After schooling for approximately 5 years, I seek to be employed in a very successful firm and to change the being of the citizens of the nation and the world.

c. PERSONAL VIEW TOWARDS EDUCATION

I feel that education is a critical part to society. Ignorance is one of the wrongs with human kind and by education we help to prevent that. Education leads to success. It is through education that society can change its being and challenge the individual, stimulate ingenuity and resourcefulness and yields a rewarding sense accomplishment.

d. DESCRIBE WHAT KEEPS YOU MOTIVATED IN LIFE

My motivation lies in my own self-content. Looking forward to the happiness I can create for myself by completing a proposed goal is what keeps me motivated.

CHAPTER ONE OBJECTIVES (SELF-MONITOR)

a. Briefly describe unifying themes that pervade the science of biology.

The science of biology is pervaded by unifying themes. Themes as such include: the structural level on which life is organized which has emergent properties; Cells are the basic units of structure and function of an organism; the continuity of life is based on heritable information in the form of DNA; a feeling for organisms enriches the study of life; structure and function are correlated at all levels of biological organization; organisms interact continuously with their environments; the dual faces of life on Earth are diversity and unity; the core theme of biology is evolution; science as a process of inquiry often involved hypothetico-deductive thinking; science and technology are functions of society; biology is a multidisciplinary adventure.

b. Diagram the hierarchy of structural levels in biology.

c. Explain how the properties of life emerge from complex organization.

The properties of life emerge from complex organization. Firstly, atoms are ordered into complex biological molecules. These molecules of life are then arranged into structures called organelles, which are the components of cells. Although some organisms consist of single cells, multi-cellular organisms have its similar cells grouped into tissues and the specific arrangement of tissues form organs. It is through this hierarchy that all biological processes transcend and life emerges.

d. Describe seven emergent properties associated with life.

Seven emergent properties associated with life include:

1. Order: all other characteristics of life emerge from an organisms complex organization.

2. Reproduction: Organisms reproduce their own kind.

3. Growth and development: Heritable programs in the form of DNA direct the pattern of growth and development.

4. Energy utilization: Organisms take in energy and transform it to do many kinds of work.

5. Response to the environment: Organisms reponse to environmental stimulus as protection.

6. Homeostasis: Regulatory mechanisms maintain an organism's internal environment withing tolerable limits, although the external environment may fluctuate.

7. Evolutionary adaptation: Life evolved as a result of the interaction of organisms with one another and their environments.

e. Explain how technological breakthroughs contributed to the formulation of the cell theory and our

current knowledge of the cell.

Technological breakthroughs have aided in the formulation of the cell theory and our current knowledge of the cell. A powerful instrument called the electron microscope has been able to expose the complex structure of cells. This instrument proved an improvement to the discoveries of the English scientist, Robert Hooke, and his contemporary, Anton van Leeuwenhoek. The electron microscope showed that all cells are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings and that every cell, at some point in its life span, contains DNA.

f. Distinguish between prokaryotic and eukaryotic cells.

I already know the distinguished factors between prokaryotic and eukaryotic cells as I familiarized myself with it when I took Biology Honors.

g. Explain, in their own words, what is meant by "form fits function."

By “form fits function“, I believe that it is meant that the biological structure of an organism hinders what an organism does and how it works. Likewise, knowing a structures function can give insight on its construction.

h. List the five kingdoms of life and distinguish among them.

I know the five kingdoms of life and can distinguish among them as I learned it in my 9th grade Biology Honors class.

i. Outline the scientific method.

I can outline the scientific method as every science class since grade school, which I have taken, has placed emphasis on the scientific method.

h. Distinguish between inductive and deductive reasoning.

I can distinguish between inductive and deductive reasoning as there have been many hands on classes I’ve taken which have introduced the difference. For example, my Honors Biology course, Honors Chemistry Course and Honors Physics Course placed an emphasis on the differences between the reasoning.

i. Explain how science and technology are interdependent

Science is a process used to test accepted truths and answer questions in relation to nature. Technology allows scientists to answer and work on questions that were previously unanswered or unapproachable.

CHAPTER TWO OBJECTIVES (SELF-MONITOR)

a. Define element and compound.
An element is a substance that cannot be broken down to other substances by chemical reactions. A compound is produced when two or more elements may combine in a fixed ratio and can be broken down.

b. State four elements essential to life that make up 96% of living matter.
Four elements essential to life that make up 96% of living matter are:
carbon, oxygen, hydrogen, nitrogen
c. Describe the structure of an atom.
The atom is the smallest unit of an element. An atom is made up of closely packed together protons, which carry a positive charge and neutrons which are neutral to form the nucleus. The electrons, in the atoms outer shells, move about this nucleus.
d. Define and distinguish among atomic number, mass number, atomic weight, and valence.
The atomic number of an atom is the number of protons in its nuclei, each unique to a certain element. The atomic number is written is a subscript to the left of the symbol for the element.
The mass number is the sum of protons plus neutrons in the nucleus of an atom. The mass number is written as a superscript to the left of an element's symbol.
The atomic weight of an element is what is technically the total atomic mass or mass number. The atomic weight tells us the approximate mass of the whole atom.
Valence is the bonding capacity - a certain number of covalent bonds that must be formed for the atom to have a full complement of valence electrons - of each atom sharing electrons.
e. Given the atomic number and mass number of an atom, determine the number of neutrons.

Helium:

Atomic number: 2

Mass number: 4

Number of neutrons = 2

f. Explain the octet rule and predict how many bonds an atom might form.

The octet rule states that When atoms react, they tend to achieve an outer shell having eight electrons. The octet rule can be used to explain the number of covalent bonds an atom forms. This number normally equals the number of electrons that atom needs to have a total of eight electrons (an octet) in its outer shell.

g. Define electronegativity and explain how it influences the formation of chemical bonds.

According to this concept, each kind of atom has a certain attraction for the electrons involved in a chemical bond. This "electron-attracting" power of each atom can be listed numerically on an electronegativity scale. When atoms react with each other, they "compete" for the electrons involved in a chemical bond. The atom with the higher electronegativity value, will always "pull" the electrons away from the atom that has the lower electronegativity value. The degree of "movement or shift" of these electrons toward the more electronegative atom is dependent on the difference in electro negativities between the atoms involved.

h. Distinguish among non-polar covalent, polar covalent and ionic bonds.

In a non-polar covalent bond, electrons are shared equally. In a polar covalent bond, one atom is more electronegative than the other, and so electrons of this bond will not be shared equally. In an ionic bond, cations - a positive charged ion- and anions - a negatively charged ion - attract each other.

i. Describe the formation of a hydrogen bond and explain how it differs from a covalent or ionic bond.

A hydrogen bond occurs when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom. It differs from a covalent or ionic bond in that the hydrogen bond is a weak electrical attraction between a negatively charged atom and a positively charged atom in which the contact between molecules can be brief.

THEMES

Cells are an organisms basic units of structure and function

Chapter 2 exemplifies how about 25 of the 92 natural elements are known to be essential to life. Elements, like cells, are required by organisms. Just four of the natural elements - carbon, oxygen, hydrogen and nitrogen, make up 96% of living matter. The chemical context of life is the most fundamental branch of life.

Structure and function are correlated at all levels of biological organization.

Chapter 2 emphasized the correlation of structure and function as it discusses the atom. When speaking of the atom, it is evident, for instance, the number of bonds the atom will form by the number of electrons required to complete that atom's valence shell.

Evolution is the core theme of Biology.

Chapter 2 explained the chemical conditions on the early Earth that set the stage for the origin and evolution of life. "Chemical reactions and physical processes on the early Earth created an environment that made life possible. And life, once it began, transformed the planet's chemistry," stated Chapter 2 (pp 38) As the definition its definition states, evolution is the change of a species over time, with relation to other organisms and its environment. This chapter provided an introduction to how chemical evolution on the early Earth made the origin of life possible.

Organisms are open systems that interact continuously with their environments.

This chapter provided how atoms combine and interact by chemical bonding to form molecules. Molecules consist of two or more bonded atoms. It likewise emphasized how when an ionic bond combines with a water atmosphere, it becomes relatively weak, exposing how organisms are affected through their interaction with environments.

Science as a process

Chapter 2 exemplified the theme of "Science as a process" as it outlines the structure of an atom, moving on to the process undertaken to essentially determine the number of subatomic particles in each atom.

CHAPTER THREE OBJECTIVES (SELF-MONITOR)

a. Describe how water contributes to the fitness of the environment to support life.

Life adapts to its environment through natural selection, but for life to exist at all in a particular location, the environment must first be a suitable abode. Water contributes to Earth's habitability by moderating temperatures.

b. Describe the structure and geometry of a water molecule, and explain what properties emerges as a result of this structure.

The water molecule is deceptively simple: two hydrogen atoms are joined to the oxygen atom by a single covalent bond. Because hydrogen is more elcetronegative than hydrogen, the electrons of the polar bonds spend fractionally more time closer to the oxygen atoms. This results in the oxygen region of the molecule having a slight negative charge and hydrogens having a slight positive charge.

The anomalous properties of water arise from attractions among these polar molecules. The molecules are thus held together by a hydrogen bond. Collectively, these hydrogen bonds are responsible for: water's cohesive behavior, its ability to stabilize temperature, it's expansion among freezing and its versatility as a solvent for life.

c. Explain the relationship between the polar nature of water and its ability to form hydrogen bonds.

The water molecule is a polar molecule, meaning that it has opposite charges on opposite ends. The anomalous properties of water arise from attraction among these polar molecules. The attraction is electrical; a slightly positive hydrogen of one molecule is attracted to a slightly oxygen of a nearby molecule. The molecules are thus held together by a hydrogen bond.

d. List five characteristics of water that are emergent properties resulting from hydrogen bonding.

Five characteristics of water that are emergent properties resulting from hydrogen bonding include:

Cohesion

Adhesion

Surface Tension

Specific Heat

and it's versatility as a solvent for life.

e. Describe the biological significance of the cohesiveness of water.

Water molecules stick together as a result of hydrogen bonding. When water is in liquid form, its hydrogen bonds are very fragile. They form, break and re-form with great frequency. Water molecules are constantly forming new bonds with a succession of partners. Thus, at any instant, a substantial amount of water molecules are bonded to their neighbors, giving water more structure than most liquids - cohesion.

f. Distinguish between heat and temperature

Heat is a measure of the total quantity of kinetic energy due to molecular motion in a body of matter.

Temperature measures the intensity of heat due to the average kinetic energy of the molecules.

g. Explain how water's high specific heat, high heat of vaporization and expansion upon freezing affect both aquatic and terrestrial ecosystems.

The high specific heat of water makes ocean temperatures quite stable, creating a favorable environment for marine life. The water that covers most of planet Earth keeps temperature fluctuations within the limits that permit life. Also, because organisms are made primarily of water, they are more reliable to resist changed in their own temperatures than if they were made of a liquid with a lower specific heat.

Water's high heat of vaporization helps moderate Earth's climate. A considerable amount of solar heat absorbed by tropical seas is consumed during the evaporation of surface water. Then, as moist tropical air circulates poleward, it releases heat as it condenses to form rain. As substances evaporate, the surface of the liquid that remains behind cools down. This evaporative cooling of water contributes to the stability of temperature in lakes and ponds and also provides a mechanism that prevents terrestrial organisms from overheating.

The ability of ice to float because of the expansion of water as it solidifies is an important factor in the fitness of the environment. If ice sank, then eventually all ponds, lakes, and even oceans would freeze solid making life, as we know it impossible on Earth. The floating ice insulates the liquid water below, preventing it from freezing and allowing life to exist under the frozen surface.

h. Explain how the polarity of the water molecule makes it a versatile solvent.

Water is an unusually versatile solvent because its polarity attracts it to charged and polar substances. When ions or polar substances are surrounded by water molecules, they dissolve and are called solutes.

i. Write the equation for the dissociation of water, and explain what is actually transferred from one molecule to another.

H2O Û H+ + OH-

Occasionally, a hydrogen atom is shared between two water molecules in a hydrogen bond shifts from one molecule to another. When this happens, the hydrogen atom leaves its electron behind, and what is actually transferred is a hydrogen ion. The water molecule that lost a proton is now a hydroxide ion

(OH-).

j. Explain the basis for the pH scale.

The basis of the pH scale is the H+ and OH- concentrations. The pH scale compresses the range of H+ and OH- concentrations by employing a common mathematical device: logarithms.

k. Explain how acids and bases directly or indirectly affect the hydrogen ion concentration of a solution.

Acids donate additional H+ in aqueous solutions as bases donate OH- or accept H+ in solutions. In an acidic solution, [H+] is greater than [OH-], and the pH is less than 7. In a basic solution, [H+] is less than [OH-], and the pH is greater than 7.

Themes:

Organisms interact continuously with their environments.

The structural level on which life is organized which has emergent properties,