Bio 1000 Human Biology for Non-Majors

Introduction to Biology and Chemistry Biology is the study of life

Characteristics of Life Form and size Chemical composition Metabolism Irritability Homeostasis – Dynamic equilibrium Growth and life cycle Reproduction

Human Uniqueness Environmental alterations Speech Tools Social organization Cultural heritage Reasoning & abstract thoughts

Biology as a Science Dynamic Scientific Method

The success and credibility of science is based on the willingness of scientists to follow two "rules:"

*1. Expose new ideas and results to independent testing and replication by other scientists. *2. Abandon or modify accepted facts or theories in the light of more complete or reliable experimental evidence. *from Voodoo Science: The Road from Foolishness to Fraud. By Robert L. Park Scientific

Scientific Method An informal process used by scientists to gather and analyze data.

1. Observe some aspect of the universe. 2. Develop a model that is consistent with what you have observed. 3. Use the model to make predictions (hypotheses). 4. Test those predictions by experiments or further observations. 5. Modify the theory in the light of your results. 6. Go to step 3.

Experiment! An experiment is done to test the hypothesis, not to prove that it is correct. A control experiment is done to make sure that the methods used do not create an effect that masks what you are looking for.

Data The facts gathered during the experiment. These can be numeric data or observations.

Conclusion Do the data support the original hypothesis? If not the hypothesis is rejected. If so the hypothesis is provisionally supported. Stays supported unless new data is found that is inconsistent with the original hypothesis. A new hypothesis is formulated.

Theory A collection of many conclusions and observations combined into a model of how a particular process works. A theory in science is not a guess or hypothesis. Einstein’s Theory of Relativity Darwin’s Theory of Evolution

Laws and Principles After many years, theories evolve into Laws or Principles. e.g. Newton’s Law of Gravity.

Levels of organization Chemical/Molecular Examples - water, proteins Cellular; Cytology Smallest living units, example - muscle cell Tissue; Histology Cells combining for a common function, example - muscle tissue

Organ Tissues combining for a common function, heart System – e.g. Cardiovascular system Organism – Human Being

Chemistry Atom The smallest part of matter that still retains its chemical and physical properties. An element is a substance made of all the same atoms. There are 92 naturally occurring elements. The most common in the human body are...

Subatomic Particles Neutrons – Particles with no electric charge Protons - Particles with a positive charge Electrons – Particles with a negative charge

Ion Atoms have no overall charge; they are neutral. But we know that they have protons (positively charged particles) in the nucleus. Electrons are negative particles which cancel the protons charge. So in an atom there are equal numbers of electrons and protons. An ion is an atom which has lost or gained an electron.

Element Chemicals containing only one kind of atom

Compound Different elements combined together

Molecule Chemical structure containing more than one atom Atoms may be the same or different

Water

2/3 of our body Single most important constituent of the body

pH scale is a measure of the hydrogen ion content of a solution; it measures how acidic or basic a solution is

Acid In an acid there are more H+ than OH- On a pH scale any value below 7 is considered acidic

Bases have fewer hydrogen ions and more hydroxide ions Readings on the pH scale for bases are 7- 14

Organic Compounds Based on CARBON Predominate in the human body

Carbohydrates Sugars and starches Energy source E.g. Glucose is a simple sugar

Glycogen is stored glucose

Lipids Fats and oils Tremendous energy source Structure of cell membranes Making some hormones

Proteins Body structure Fighting disease Enzymes Made of amino acids

Nucleic Acids DNA Makes up genes

Nucleic Acids RNA – Follows instructions on the DNA ATP – Cellular energy