Ch 5 Photosynthesis & Respiration

What is Photosynthesis? The process of photosynthesis is a chemical reaction. It is the most important chemical reaction on our planet.

Autotrophs/producers: self feeders, organisms capable of making own food –Photoautotrophs: use sun energy – Chemoautotrophs: use chemical energy e.g. bacteria chemosynthesis-makes compounds from chemical energy in methane

Describe Photosynthesis

Photosynthesis process of changing light energy to chemical energy Energy stored as sugar plants and some algae Plants need light energy, CO 2, and H 2 O Takes place in chloroplasts, using chlorophyll (green pigment)chloroplasts chlorophyll

What “Food” do Plants Make? The “food” plants make is a sugar called glucose (C 6 H 12 O 6 ). Glucose and oxygen (O 2 ) are made during photosynthesis.

What is the Equation for the Chemical Reaction of Photosynthesis?

What is the equation for the chemical reaction of photosynthesis? Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

What happens during photosynthesis?

Plants capture light energy and make glucose Sunlight provides energy needed by chlorophyll to change molecules of CO 2 and H 2 O into glucose Oxygen is released

What happens during photosynthesis? CO 2 enters leaf through holes called stomata stomata CO 2 combines with energy in chloroplasts to make glucose sugar is moved through tubes to roots, stems and fruits of plant Some sugar is used right away by plant for energy; some is stored as starch; and some is built into plant tissue

Why is this important to us?

important We cant make own food (glucose, energy), we must get it from plants. Plants are the first step in the food chain. oxygen released during photosynthesis is necessary for all living things.

Learn more about photosynthesis at:

What is Cellular Respiration?

Cellular Respiration release of chemical energy for use by cells. All cells require energy for life

How Do Organisms Get Energy From Food? Animals cannot make their own food like plants can. But, BOTH plants and animals must break down (digest) food in order to get energy from it (so they can live, grow, & develop) Cells do this 2 ways: cellular respiration and fermentation

Types 1.Aerobic (with Oxygen) - inside mitochondria by plants and animals - Prokaryotes- takes place in cell membrane

2. Anaerobic (without Oxygen) Bacteria and yeast don’t need oxygen to carry out cellular respiration different waste products (bread to rise, pop fizz) C 6 H 12 O 6 --> 2C 2 H 5 OH + 2CO 2 + energy GlucoseEthanol

What is Cellular Respiration? Once the energy from sunlight is changed to chemical energy by photosynthesis, an organism has to transform chemical energy into a form that can be used by the organism.photosynthesis This process is cellular respiration.

Describe Cellular Respiration

The breakdown of glucose molecules to release energy Takes place in all living things step by step process

What is the chemical equation for cellular respiration?

Energy stored in cells as ATP ATP -form of energy “currency” goes where needed power chemical reactions. ATP (adenine triphosphate) -phosphate groups store energy, released when bonds broken ATP  ADP + P + energy

Read how photosynthesis & respiration are related: er00/8th/energy/sciber/photosyn.htm

Homework Pg Restate

Begins with the SUN Photosynthesis 6CO 2 + 6H 2 O + sunlight & chlorophyll  C6H 12 O 6 + 6O 2

Chemical reaction green plants use H 2 O, CO 2 and sunlight to make glucose. ENERGY stored in glucose; glucose stored as starch.

PRODUCERS/Autotrophs- make own food (glucose)

Autotroph/producer: An organism that makes its own food. Plants and some other organisms make food from sunlight energy (photosynthesis)

- use most for themselves.

- use cellular respiration to supply energy needed to live.

CELLULAR RESPIRATION - chemical reaction that releases energy in glucose. 6O 2 + C 6 H 12 O 6 --> 6H 2 O + 6CO 2 + energy

Energy not used by producers passed on to organisms that can’t make own.

CONSUMERS- can’t make own food

Heterotrophs/consumers: Why do we say that they get energy directly or indirectly from plants

Types of Consumers Primary consumers Are herbivores (plant-eaters)

Most of the energy the primary consumer gets from the producer is used by the consumer.

Types of heterotrophs: 1.Herbivore: organisms which feed only on autotrophs (plants). Examples: deer, rabbits, horses

Some of the energy moves into the atmosphere as heat.

Most of the energy is lost or used. What is left is available for another consumer.

Secondary Consumer A consumer that eats another consumer for energy Can be Predator Scavenger Omnivore or Carnivore

2. Carnivores Organisms which feed only on other heterotrophs (animals). Examples: wolves, hawks, anteaters

Most of the energy the secondary consumer gets from primary consumer is used

Some of the energy is lost as heat, but some energy is stored and can passed on to another consumer.

Tertiary consumer A consumer that eats a consumer that already ate a consumer: carnivore predator scavenger

Omnivores eat plants and animals (producers and consumers)

3. Omnivores Organisms which feed on both plants and animals Examples: humans, bears, robins, raccoons Black rats are omnivores. They will eat grain, fruit, corn, insects and eggs.

Predators- hunt and kill prey Prey- are hunted

Scavengers- eat dead consumers

5. Scavengers Animals which feed on other animals which are already dead (scavengers don’t kill their own prey). Examples: hyena, crows, vultures, ants.

Decomposers- breakdown dead animals remains and return to soil. Ex. Fungi (mushrooms & mold), some bacteria

4. Decomposers Animals which feed on decaying organic matter (rotting plants and animals). Examples: earthworms, fungus, some bacteria Mushrooms (right) and earthworms are decomposers

FOOD CHAIN.- sequence of organisms through which nutrients are passed

Examples of food chains Leaf caterpillar robin mosquito Clover deer wolf Minnow salmon bear Grass cow human Fly frog snake alligator

Energy pyramids show Amount of available energy decreases up the food chain It takes a large number of producers to support a small number of primary consumers It takes a large number of primary consumers to support a small number of secondary consumers

Trophic Levels Each link in a food chain is a trophic level. –Autotroph (beginning of the chain) - first trophic level. –Herbivore (eats the autotroph) - second trophic level. –Carnivore (eats the herbivore) - third trophic level.

How many trophic levels? Rotting fruit Fly frog snake Which organism is at the second trophic level? Name the carnivores: What kind of organism is a fly? At which trophic level is the snake? Can anyone in this chain be an omnivore? Who is the highest order consumer in this chain?

How many trophic levels? Clover deer wolf How many carnivores? How many autotrophs? Which is at the third trophic level? At which trophic level is the herbivore? Name the next link in the chain if the wolf dies and decomposes.

Energy Pyramid: Shows the movement of energy through an ecosystem Bottom of the pyramid: 1 st trophic level: Autotrophs/producers: the most energy is here. Second trophic level: herbivores (first order consumers) are here. Some energy is lost. Third trophic level: omnivores, small carnivores. More energy is lost. Fourth trophic level: top carnivores and omnivores. The least amount of energy is here. Source of energy for the energy pyramid is The Sun!

Energy is lost as it moves up the pyramid. The pyramid is like climbing steps: Energy is lost as you move up the stairs You have the most energy at the bottom You have the least energy at the top

Because less energy is available to for the consumers at the top, there are less carnivores than plants.

Food Webs: interconnected food chains show the feeding relationships

Food Web A food web shows all the different food chains in an ecosystem. How many different food chains are in this web?

How many food chains is the mosquito in? What is getting energy from the worm? How many autotrophs are in this web? Is the energy flowing from the alder to the deer, or from the deer to the alder?

What kind of ecosystem would have a food web like this one? Which predators have the most sources of food in this web? What is at the beginning of each food chain in this web? Is the Herring a herbivore, an omnivore or a carnivore? How many food chains do you see here? What would happen if the snails were eliminated from this web?

Homework