This document provides an overview of key concepts in biology, including: 1. It defines four characteristics of life - all forms contain DNA, extract and use energy, respond to stimuli, and reproduce. 2. It describes the levels of complexity in organism organization from atoms to cells to tissues to organs to organ systems. 3. It explains how organisms use and transport energy through cellular respiration and metabolism to power growth, development, and chemical reactions.

1. EXPLORING CREATION
WITH BIOLOGY
Modules 1A and 5

2. Characteristics of Life




1. All life forms contain DNA
2. All life forms have a method by which they
extract energy from the surroundings and
convert it into energy that sustains them
3. All life forms can sense changes in their
surroundings and respond to those changes
4. All life forms reproduce

3. 1. All life forms contain DNA
Organization
(The level of
complexity)
•
•
•
•
•
•
•
Organism
Organ System
Organs
Tissues
Cells
Molecules
Atoms/Elements

4. 2. Energy Use

Energy Use
a.
b.
c.
d.
Organisms need energy
constantly to build molecules
(synthesis) and cells and to
break down substances (such as
food for nutrition or invading
bacteria cells).
Organisms must transport
nutrients to be used in cellular
respiration to produce energy.
An organisms’ chemical reactions
(all of which use or store energy)
are called its metabolism
Used for growth and
development

5. 3. Respond to Stimuli
Respond to Stimuli
a.
b.

A quick, non-permanent change
Stimulus – any condition that causes an organism to react.
Example – A loud noise (stimulus) causes
your dog to run under the bed (response).
Adjust to Environment
a.


Homeostasis - the regulation of an organism’s internal
environment to maintain conditions suitable for life
Ex: Sweating when you get hot to cool down
Ex: Getting rid of wastes by excretion

6. 4. All Life Forms Can
Reproduce

Reproduction
a.
b.
c.
Important at the specie level (organisms must replace
themselves so the entire species will survive.)
May occur only at a cellular level.
May be asexual (only one individual contributes genetic
material) or sexual (two individuals contribute genes).

7. Scientific Method

8. Atoms, Molecules, Compounds

9. Majority of an atom’s properties are
determined by the number of
electrons

10. Physical Change Vs Chemical
Change

11. Phases of Matter

12. Diffusion vs. Osmosis

13. Organic Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids

14. Carbohydrates

15. Carbohydrates - Functions
Functions of carbohydrates
Energy is released when carbohydrates are
digested. This is because glucose is used for
cellular respiration.
a.
i.
ii.
Monosaccharides (simple sugars) provide short
term energy.
Starch and glycogen are considered longer term
energy sources because they can be broken down
over a period of minutes, hours or days to provide
glucose for energy.

16. Lipids
Functions of lipids
a.
Because of the numerous bonds and the way the
body stores lipids, they can be used as very longterm (weeks, months) energy sources.
Ex. Bears accumulate a layer of fat before winter
(when food will be less available)
b.
Fats stored in the body act as insulation and
protection for internal organs.
c.
Some hormones are composed of lipids (steroids).

17. Proteins
Functions of proteins
a. Some proteins absorb light to maintain
homeostasis. These are called pigments. They
create color by reflecting certain wavelengths of
light.
 Ex. Chlorophyll absorbs light to gather energy
for photosynthesis.
b. Some proteins are constructed by cells to bind
with and inactivate foreign particles in the body.
These are called antibodies.
c. Proteins may form structural parts in an
organism – such as keratin in hair and nails.

18. Proteins - Continued
d.
e.
f.
Some proteins are used for
transport through the cell
membrane or in the bloodstream
(ex. hemoglobin)
Some proteins are used for
communication between cells.
These may be hormones (insulin)
or neurotransmitters.
Enzymes (a special class of protein)
act to speed up chemical reactions.

19. Enzymes
A.
Enzymes help maintain homeostasis
1.
2.
All organisms have metabolism. Metabolism includes all of
the chemical reactions that occur in that organism.
Metabolism includes digestion and production. Metabolism
(chemical reactions) requires certain conditions to occur.
Enzymes regulate metabolism, allowing life to continue.
Metabolism (each reaction) has a small range of
temperature and pH at which it can proceed. Each
reaction also needs some energy to begin. This is called
activation energy. Enzymes allow reactions to occur at
lower activation energy (body temperature). This means
enzymes act as biological catalysts (speeds reactions).

20. Graph With and Without
Enzyme

21. Enzymes - Continued
2.
Enzymes mediate (help) chemical reactions using a
specific chemical pathway (series of steps).
a.
b.
c.
d.
The enzyme collides with the substrate.
The enzyme and substrate fit together at the active site
like a lock and key.
The enzyme changes the substrate in some way
i.
It may help break the substrate apart.
ii.
It may hold two (or more) substrates together
closely so the two parts interact.
The enzyme and the substrate separate. The substrate
(now changed) is called the product.
Mr. Wanamaker's Enzyme Animations

22. Enzyme Visual

23. Enzyme Characteristics
1.
2.
3.
Enzymes are biological catalysts. This means they speed
up chemical reactions in living things.
Enzymes are specific. This means enzymes will catalyze
only one specific reaction because only certain substrates
fit due to the shape of the active site.
Enzymes are reusable. Notice in the diagram above that
the enzyme did not change shape or split. This means it
can now fit with another substrate or set of substrates and
repeat its role in speeding up the reaction.
Reversible Enzyme Reactions Animation

24. Nucleic Acids
A.
Nucleic Acids
1.
Carbon, hydrogen, oxygen, nitrogen, and
phosphorus make up subunits called nucleotides.
Many nucleotides bond together to make up a
long chain – a nucleic acid.
a. DNA is a double chain of nucleotides found in
all living cells.
b. RNA is a single chain of nucleotides that
provides the structures needed for the cell to
make proteins.

25. DNA Visual

26. DNA vs. RNA

27. Nucleic Acid Function

28. pH

29. Acids vs Bases

30. Acids and Bases

31. Acids vs. Bases - Properties