Transcript Chemistry Of Living Organisms

Characteristics of
Life
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What is alive
• Organisms include:
bacteria, plants,
animals, fungi, &
protists
• Does not include
viruses.
– Viruses are not
cells.
– Viruses are
proteins and
nucleic acids
Ebola virus: Referred to as a
hemorrhagic virus because it causes
hemorrhages in its victims.
All organisms are composed of cells
– Cells are the basic
unit of structure
and function of all
living things
– Organisms are:
Unicellular
Multicellular
Organization
• Living things are
all highly
organized.
– Organisms take
substances from
environment and
organize them in
complex ways.
Cross section of a root showing root hairs
on the outer surface.
Energy use
•
Energy is used to
maintain organization.
• Metabolism: Sum of
all chemistry/ energy
in a living thing.
Think: what does this bird use
energy for?
Cardinal
Homeostasis
• Maintaining a steady
internal environment.
– External environment
is always changing.
Think: what does your body do to
maintain homeostasis?
Baby Sea Lion
Growth
• All living
organisms grow.
– Growth occurs
by cell division
and cell
enlargement
Bacteria dividing after growth stage.
Reproduction
• All species of
organisms are capable
of reproducing.
– Reproduction is
essential to the
species but not the
individual.
– Reproduction is the
transfer of genetic
material from
generation to the next
Think: What happens to a species
if they do not reproduce?
Answer these questions in your
summary
1. List all the characteristics of living things.
2. Entropy is the natural tendency towards
disorder. What do living things do that counters
entropy?
3. What is the chemistry/ energy use of living
things called?
4. Why are viruses not alive?
5. Name 2 ways organisms maintain
homeostasis (other than those mentioned in
this lecture).