1. Ecosystems: Life & Energy

2. Ecosystems Everything is connected. Ecosystem
All the organisms living in an area together with their physical environment
Examples: coral reef, oak forest 2

3. Components of an Ecosystem
Biotic factors
Living and once living parts of an ecosystem
Plants
Animals
Dead plants and animals
Waste products from plants and animals
Abiotic factors
Nonliving parts of an ecosystem
Air
Water
Rocks
Sand
Light
Temperature 3

4. Components of an Ecosystem
Organism
An individual living thing
2 types of organisms
Prokaryotic
Simple, smaller
Has cytoplasm and cell membrane, but no nucleus
Eukaryotic
More complex, larger
Has cytoplasm, cell membrane and nucleus
Cell membrane
Function – to allow things in and out of the cell 4

5. 7 Characteristics of Life
Must have all 7 characteristics to classify as a prokaryote or eukaryote
1. Reproduction
2. Growth
3. Definite Form/Limited Size (cells)
4. Respond to Stimuli
5. Change over time
6. Use energy
7. Limited lifespan

6. Homeostasis “inner balance” Controls conditions inside the body
Maintained by using feedback loops
Ex. How a body responds to a stress

7. Structure of Organisms
Monomers
Small building blocks
Ex. Legos
Polymers
Large molecules with repeating parts
Ex. Creation build from legos

8. Organic Compounds Contain carbon Associated to life 4 types
1. Carbohydrates (polymer)
Monosaccharides (monomers)
Examples - Sugars, starches
2. Proteins (polymer)
Amino acids (monomers)
Example - Enzymes
Make reactions happen in the body
Life wouldn’t exist without them

9. Organic Compounds, cont.
3. Lipids (polymer)
Fatty acids (monomers)
Examples - Fats, oils
4. Nucleic Acids (polymer)
Nucleotides (monomers)
Examples – DNA, RNA

10. Components of an Ecosystem
Species
A group of organisms that are closely related
Population
All the members of the same species that live in the same place at the same time
Organisms in a population breed with each other usually not with other populations

11. Components of an Ecosystem
Community
A group of various species (populations) that live in the same place and interact with each other
Example: Pond
Ecosystem
All groups of communities
Biosphere
All ecosystems 11

12. Homework
Page 96
Section 1 Review
#1, 4-6

13. Energy Flow in Ecosystems
The ultimate source of energy for all organisms is the sun.
Photosynthesis
When plants use sunlight to make food (sugar)
CO H2O →→ C6H12O O2
Sunlight

14. Photosynthesis Occurs in leaves of plants Chloroplast
Specific place in leaf where photosynthesis occurs
Looks like a little green football

15. Energy Flow Plants make food (sugar) which are carbohydrates.
Animals eat the plants, obtaining the energy from the plants.
Animals use this energy to….
Move
Grow
Reproduce

16. Transfer of Energy Producer Consumer
An organism that makes its own food
Also called autotrophs (self-feeders)
Consumer
An organism that gets its energy by eating other organisms.
Also called heterotrophs (other-feeders)

17. Exception to the Rule
Ecosystem deep in the ocean where no sunlight reaches
Worms, clams, crabs, mussels live here
Consumers
Bacteria living here used hydrogen sulfide to make its own food
Producers

18. What Eats What Producer Consumer Herbivore Carnivore Omnivore
Cows, sheep, deer, grasshoppers
Carnivore
Lions, hawks, snakes
Omnivore
Bears, pigs, cockroaches
Decomposer
Eats dead organisms (fungi, bacteria)

19. Cellular Respiration Breaking down food into energy
Cells absorb oxygen
Helps to release energy from food
The energy is used for daily activities in the organism’s body.
C6H12O6 + O2 →→
CO2 +
H2O +
energy

20. Cellular Respiration Occurs in mitochondria Exception to the rule
Organelle in each cell
Exception to the rule
Cellular respiration does not occur in the mitochondria in organisms that go through fermentation
Outcome of the process
ATP
Molecules of energy

21. Energy Transfer Food Chain Food Web
Transferring energy when one organism eats another and so on
Food Web
Many food chains linked together

22. Energy Transfer, cont. Trophic Levels
Every step when energy is transferred in a food chain or food web
Only 10% of energy is available to next trophic level
Energy affects the ecosystem in two ways
Fewer organisms at higher trophic levels
Limits the number of trophic levels in an ecosystem

23. Assignment
Page 123
Section 1 Review
#1-5

24. Review Questions Pages 109-110 #6, 10, 12-13, 18-19 Pages 135-136
#6, 9-15, 19-20, 24-26