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, CO2, and H2O

• Takes place in chloroplasts, using chlorophyll (green pigment)

What “Food” do Plants Make?

The “food” plants make is a sugar called glucose (C6H12O6).

Glucose and oxygen (O2) 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 CO2 and H2O into glucose

• Oxygen is released

What happens during photosynthesis?

• CO2 enters leaf through holes called stomata

• CO2 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:

http://www.ftexploring.com/me/photosyn1.html

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

Types1. 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 6H12O6 --> 2C2H5OH + 2CO2 + energy

• Glucose Ethanol

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.

This process is cellular respiration.

Describe 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?

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:

http://www.usoe.k12.ut.us/curr/science/sciber00/8th/energy/sciber/photosyn.htm

Homework

• Pg 96 1-5 Restate

•Begins with the SUN

•Photosynthesis

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

• Chemical reaction green plants use H2O, CO2 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.

6O2 + C6H12O6 -->  6H2O + 6CO2 + 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: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.

Carnivores2.

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. Omnivores3. 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

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. Decomposers4. 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 LevelsTrophic LevelsEach 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?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: 1st 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 WebFood WebA 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