Transcript Bio 1000 Human Biology for Non-Majors

Bio 1000
Human Biology for Non-Majors
Introduction to Biology and
Chemistry
• Biology is the study of life
Characteristics of Life
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Form and size
Chemical composition
Metabolism
Irritability
Homeostasis – Dynamic equilibrium
Growth and life cycle
Reproduction
Human Uniqueness
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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
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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
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 OHOn
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 714
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
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Fats and oils
Tremendous energy source
Structure of cell membranes
Making some hormones
Proteins
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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