Ecosystems: Life & Energy

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

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

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

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

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

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

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

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

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

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

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

Energy Flow in Ecosystems The ultimate source of energy for all organisms is the sun. Photosynthesis When plants use sunlight to make food (sugar) CO2 + H2O →→ C6H12O6 + O2 Sunlight

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

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

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)

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

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)

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

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

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

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

Assignment Page 123 Section 1 Review #1-5

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