Bio 1000Human 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 ofscience is based on thewillingness of scientists tofollow two "rules:"

*1. Expose new ideas and results toindependent testing and replication byother scientists.*2. Abandon or modify acceptedfacts or theories in the light ofmore complete or reliableexperimental evidence.*from Voodoo Science: The Road from Foolishness toFraud. By Robert L. ParkScientific

Scientific MethodAn informal process used by scientists to gather andanalyze data.

1. Observe some aspect of the universe.2. Develop a model that is consistent with whatyou have observed.3. Use the model to make predictions(hypotheses).4. Test those predictions by experiments orfurther 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, notto prove that it is correct.A control experiment is done to make sure that themethods used do not create an effect that maskswhat you are looking for.

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

ConclusionDo 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 isinconsistent with the original hypothesis.A new hypothesis is formulated.

TheoryA collection of many conclusions andobservations combined into a model of howa particular process works.A theory in science is not a guess or hypothesis.Einstein’s Theory of RelativityDarwin’s Theory of Evolution

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

Levels of organization

• Chemical/MolecularExamples - water, proteins

• Cellular; CytologySmallest living units, example - muscle cell

• Tissue; HistologyCells 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

IonAtoms have no overall charge; they are neutral.But we know that they have protons (positivelycharged particles) in the nucleus.Electrons are negative particles which cancel theprotons charge.So in an atom there are equal numbers of electronsand protons.An ion is an atom which has lost or gained anelectron.

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

Water

• 2/3 of our body

• Single most important constituent of the body

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

AcidIn an acid there are more H+ than OH-

Ona 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