BIOL 1306 Exam 1 CH 1/2

Scientific Method

methodical framework to solve problems & determine answers in a step-by-step logical format

What is the importance of the scientific method

-people give us partial (and biased) accounts of a phenomenon, so to solve this, they created the scientific method

-method that you can replicate & others can as well

Steps of Scientific Method

1. State Problem (Purpose/Observation)

2. Research Topic

3. State Hypothesis

4. Experiment

5. Analyze Data

6. Conclusion

What is the purpose

-state the problem you're attempting to solve

-be specific & avoid broad statements

Research Step

-research topic to be able to form an intelligent hypothesis

-Use diff. sources (in this order): scientific journal articles, books, newspaper articles, webpages

Hypothesis Setp

-an educated guess about the outcome of your experiment, based on knowledge/research conducted

explains what you think, not why you think that way

falsificationism

-Karl Popper

-a scientific theory is only valid if it can be falsified (aka can be proven to be not true)

Experiment Step

develop procedure to test hypothesis

-List all steps (aka the procedure), safety concerns & materials needed to experiment properly

Variable

anything that can change during an experiment

Independent Variable (IV)

variable that is controlled or manipulated by the experimenter

Dependent Variable (DV)

variable that is measured by experimenter

Control Group (CG)

group not exposed to independent variable

Analysis Step

-record results of experiment using data chart/table

Conclusion

-Compare hypothesis to experimental conclusion

-State if you proved or disproved your hypothesis

-Name errors/results that could have affected outcome

-Reject or Fail to Reject Hypothesis, there's NO accept

Atom

the smallest unit of matter that still has distinct chemical properties

Molecules

2 or more atoms

Macromolecule

-a very large molecule (polymer) made up of many smaller molecules bonded together (monomers)

-formed through polymerization

Polymerization

a polymer is a larger molecule that is made by combining smaller units (monomers)

Levels of Organization of Living Things

1. cells (Smallest)

2. tissue

3. organs

4. organ systems

5. organisms (largest)

Organelle

A tiny cell structure that carries out a specific function within the cell (ex: mitochondria & chloroplast)

Cell

smallest fundamental unit of structure and function in living organisms (prokaryotic or eukaryotic)

Tissue

in larger organisms, group of similar cells combine to make tissues (ex: skin tissue/layers)

Organs

collection of tissues grouped together performing a common function

Organ System

higher level of organization that consists of functionally related organs

(Ex: circulatory system transports blood through body & to/from lungs)

Organism

A living thing

Microgranisms

single-celled prokaryotes & single-celled eukaryotes

What are the 6 kingdoms

animalia, fungi, eubacteria, plantae, protista, archaebacteria

List the ecological levels

1. Population

2. Community

3. Ecosystem

4. Biosphere

Population

group of organisms of a single species that interact & interbreed in a common place at a particular time

Community

group of interacting species that occur together at same place/time

Ecosystem:

all of the components of an ecological system (biotic/abiotic) that influence flow of energy & elements

Biosphere

highest level of organization & collection of all ecosystems (land, water, atmosphere)

Subatomic Particles of an Atom

protons, neutrons, electrons

Atoms with the same atomic number, have the same...

same # of protons & chemical properties

isotopes

Atoms of the same element that have different numbers of neutrons

Molecules

Groups of two or more atoms held together by chemical bonds

Atoms

elements comprised of portons, neutrons, & electrons

Covalent Bond

each atom's unpaired valence electrons are shared by both nuclei to fill orbitals

Nonpolar Covalent Bond

-electrons are shared evenly b/w two atoms

-atoms similar in EN

Polar Covalent Bonds

-electrons are not shared equally b/w two atoms

-atom w/ higher EN has neg. partial charge & other atom has partial pos. charge

Ionic Bond

electrons are transferred from one atom to another; attraction b/w opposite charges

Ion, Cation, & Anion

ion- a charged atom or molecule

cation- loses an e- & has a pos charge

anion- gains an e- & has a neg. charge

Acid

substances that give up protons (H+) (pH <7)

Base

molecules or ions that acquire protons (pH > 7)

pH

-proton concentration in a solution

-pH of water = 7 (neutral)

Relationship b/w pH, acidity/basicity, & H+ conc

-Greater H+ conc = lower pH = more acidic

-Lower H+ conc = higher pH = more basic

Buffer

ompounds that minimize changes in pH

What is considered the solvent of life

water is an excellent solvent to dissolve things into a solution

Hydrogen Bond

weak electrical attractions between a partially neg/highly EN atom, like oxygen, and a partially positive hydrogen

Why is H-Bond weaker than covalent bonds

sharing of electrons in a covalent bond creates a strong, stable link, while the attraction between partial charges in a hydrogen bond is a weaker, more temporary interaction

Hydrophillic

-water-loving

-ions & polar molecules

Hydrophobic

-Water fearing

-uncharged & nonpolar compounds

Properties of water resulting from H-bonding

1. less dense as a solid

2. absorbs large amounts of energy

3. cohesive

4. adhesive

High Specific Heat

-A property of water

-Water can absorb lots of heat before changing temperature

High Heat of Vaporization

-the amount of heat necessary to cause a phase transition between a liquid and a gas

-large amount of heat is needed to vaporize liquid

Cohesive

-binding b/w like molecules

-results in high surface tension

Adhesive

binding b/w unlike molecules

What elements make up most of living matter

-Oxygen, carbon, nitrogen, and hydrogen

-O/H in water

-C building block of life

-N used for proteins/nucelic acid

Amino (NH2-R) & Carboxyl Groups (carboxylic acid)

attract or drop a proton

Carbonyl (aldehyde/ketones)

link molecules into more comlex molecules

Hydroxyl (R-OH)

weak acids

Phosphate

2 neg charges & stores ATP

Sulfhydryl (R-SH)

link together to make protein structure via disulfide bonds

Electron-Sharing Continum

degree to which electrons are shared in chemical bonds (ionic, nonpolar, & polar)