Standard 3Interdependence of Living

Systems and the Environment

6 CO2 + 6 H2O + energy (from sunlight)       C6H12O6 + 6 O2

Unit 3 - Photosynthesis & Respiration

Plants as Producers• Plants are producers. They make their own food

(autotrophs). Consumers obtain energy from other sources.

• They use the energy from light to make sugar molecules from the atoms of carbon dioxide and water.

• Plants use these sugars, along with minerals from the soil, to form fats, proteins, and carbohydrates. This food can be used immediately, incorporated into the cells of a plant as the plant grows, or stored for later use.

Producers and Consumers (03:34)

Obtaining Energy• Different organisms are classified based on how

they obtain energy for growth and development.• Autotroph = an organism capable of synthesizing its

own organic substances from inorganic compounds. Autotrophs produce their own sugars, lipids, and amino acids using carbon dioxide as a source of carbon, and ammonia or nitrates as a source of nitrogen. Photosynthetic autotrophs include the green plants, certain algae, and the pigmented sulfur bacteria

• Heterotroph = living organism that obtains its energy from carbohydrates and other organic material. All animals and most bacteria and fungi are heterotrophic.

• Decomposer = An organism that breaks down the bodies or parts of dead plant or animal matter into smaller inorganic pieces (decay). Decomposers, such as mushrooms, bacteria, and earthworms, are very important in food webs. They decompose dead organisms and wastes into elements that can be used by other organisms).

• PHOTOSYNTHESIS = The process by which plants use light energy trapped by chlorophyll to convert water and carbon dioxide into stored energy or food. (LEAF MAKES FOOD FOR THE PLANT)

Photosynthesis (11:57)

• Cells transform energy, obtained from the sun, from one form to another through the processes of photosynthesis and respiration.

• Photosynthesis = is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. Most of the time, the photosynthetic process uses water and releases the oxygen that we absolutely must have to stay alive. Oh yes, we need the food as well!

• Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar.

• Plants use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things.

• The primary source of energy for nearly all life is the Sun.• Photosynthesis is affected by temperature, light intensity, light

wavelength and carbon dioxide level.

→+ + O 2

H O2

Energy is transferred and transformed from the sun to energy-rich molecules during photosynthesis. Plants transfer and absorb the light energy during daylight hours and transform that energy to energy-rich glucose molecules. The plant then goes through respiration to obtain/break down that energy for growth. Respiration increase for plants during flowering and production stages of growth.

Plant Structure Related to Photosynthesis• Leaf - The leaf is the main site of photosynthesis and is well adapted for

this function. Most leaves are thin with a large flat surface. This gives them a large surface area for absorbing sunlight.– Stomata - The stomates are holes which occur primarily in the lower

epidermis and are for air exchange: they let CO2 in and O2 out, and control water loss. The carbon dioxide needed for photosynthesis enters the leaf through tiny pores which are mainly in the lower surface of the leaf. The leaves are thin so diffusion happens quickly because the distance through which the gases have to diffuse is short. The carbon dioxide in the air spaces of the leaf is quickly absorbed into the cells and used for photosynthesis. Oxygen which is produced as a by-product of photosynthesis is also released into the atmosphere through the open pores. The pores (stomata) are opened by guard cells.

– Photosynthesis is the source of the O2 we breathe, and thus, a significant factor in the concerns about deforestation.

Pea Leaf Stoma

Cross section of a leaf, showing the anatomical features important to the study of photosynthesis: stoma, guard cell, mesophyll cells, and vein.

Plant Structure Related to Photosynthesis• Leaf - The leaf is the main site of photosynthesis and is well adapted for

this function. Most leaves are thin with a large flat surface. This gives them a large surface area for absorbing sunlight.– Chloroplasts - Leaf cells contain many chloroplasts, which in turn

contain chlorophyll. Chlorophyll is a green pigment that absorbs light. Enzymes in the chloroplasts of the cells combine these two reactants (CO2 & Water) using light energy from the sun. The energy is absorbed by chlorophyll. Oxygen gas is a by-product of the process and is released into the atmosphere.

Photosynthesis takes place in the leaf. Leaves contain chloroplasts. Chloroplasts are a complex, discrete green structure, or organelle, contained in the cytoplasm of plant cells. Chloroplasts are responsible for the green color of almost all plants because they contain chlorophyll. The chloroplast is generally flattened and lens-shaped and consists of a body, or stroma, in which are embedded from a few to as many as 50 submicroscopic bodies–the grana–made up of stacked, disk-like plates. The chloroplast contains chlorophyll pigments, as well as yellow and orange carotenoid pigments. Chloroplasts are thus the central site of the photosynthetic process in plants.

Plant Structure Related to Photosynthesis

Plant Structure Related to Photosynthesis

• Roots - The water needed for photosynthesis enters the plant via its roots. Plant roots are covered in millions of microscopic root hairs. The water and dissolved minerals then travel from the root hair cells, through the root cells to the xylem.

• For most plants, there is as much growth above the soil surface as there is below as roots.

• In ideal conditions, roots can grow up to 1cm/day.

• The two major functions of roots are 1) absorption of water and inorganic nutrients and 2) anchoring the plant body to the ground.

• They often function in storage of food.

• TAP ROOT = A single, relatively large central root which gives rise to smaller, lateral branches; usually found in dicots. A tap root usually grows strait downward.

THE WILD CARROT

Plant Structure Related to Photosynthesis

• FIBROUS ROOT = Root system consisting of many small roots, often forming a mat which spreads out vertically and laterally in the soil. Fibrous roots do not usually penetrate very deeply in the soil. This type of system is often characteristic of monocots.

• RADICLE• An immature root.

This picture shows the fibrous root system of the

rice plant.

Viola spp

Plant Structure Related to Photosynthesis

• VASCULAR BUNDLES = Vascular bundles are clusters of xylem and phloem conducting elements that conduct food, water, and minerals throughout the plant. – Xylem - Xylem is a specialized tissue adapted to transport water and

dissolved minerals up the stem to the leaves. – Phloem - Soluble products of photosynthesis like glucose are

transported from the leaves around the plant in phloem tubes. Xylem vessels and phloem tubes are grouped together in vascular bundles and can be seen as veins in the plant. The water and dissolved minerals then travel from the root hair cells through the root cells to the xylem.

Plant Structure Related to Photosynthesis

• XYLEM = The tube-shaped, “dead” portion of the vascular system in plants that carries water and minerals from the roots to the rest of the plant.

The picture of magnified spruce wood above clearly shows the staw-like fibers of xylem.

Oak (Quercus robur) branch sectioned to

show xylem tubules arranged in growth rings.

• PHLOEM = a layer of tree tissue just inside the bark that conducts food from the leaves to the stem and roots.

 Fern Rhizome Cross Section  Three-year Tilia Stem Cross Section

Sugar Maple – internal and external structures needed for sap production, text page 560-561.

H2O + light + NADP+ + ADP + P O2 + NADPH + ATP

• Occurs in the Thylakoid memberane

• Pigments such as chlorophyll absorb light energy

• The absorbed energy is used to produce high energy molecules (ATP and NADPH) that can be used in the next phase of photosynthesis

• During the reaction water is split and O2 is produced as a waste product (aka by-product)

Light Reaction

• Key terms to remember:

• Light Reaction

• Thylakoid / Thylakoid membrane

• Grana / Granum

• Pigments / Chlorophyll

• ADP / ATP

• NADP+ / NADPH

• Electron Transport Chain

Light Reaction

H2O + light + NADP+ + ADP + P O2 + NADPH + ATP

• Reactants =• Water

• NADP+

• ADP

• Phosphorus

Light Reaction

• Products =• Oxygen

• High Energy ATP

• High Energy NADPH

http://www.youtube.com/watch?v=hj_WKgnL6MI&noredirect=1

H2O + light + NADP+ + ADP + P O2 + NADPH + ATP

Light Reaction

http://www.johnkyrk.com/photosynthesis.html

CO2 + NADPH + ATP C6H12O6 + NADP+ + ADP + P

Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)

• Occurs in the Stroma

• Enzymes use the energy stored in ATP and NADPH molecules to capture CO2 to produce carbohydrates

• The ATP and NADPH are coverted back into ADT and NADP+. These are then recycled back to the light reaction where they are used to make more ATP and NADPH

• YouTube- The Calvin Cycle or Dark Reactions (Photosynthesis).wmv

CO2 + NADPH + ATP C6H12O6 + NADP+ + ADP + P

Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)

• Key Terms

• Dark reaction / Calvin Cycle / Calvin-Benson Cycle

• ATP / ADP

• NADPH / NADP+

• Carbohydrate production / organic molecule production

CO2 + NADPH + ATP C6H12O6 NADP+ + ADP + P

• Reactants =

• Carbon Dioxide

• NADPH

• ATP

Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)

• Products =• Glucose

• ADP

• NADP+

• Phosphorus

6 CO2 + 6 H2O + energy (from sunlight)       C6H12O6 + 6 O2

• Reactants =• Carbon Dioxide (low

energy compound)

• Water

Light + Dark Reaction

• Products =• Glucose (high

energy compound)

• Oxygen

• ADP/ATP and NADP and NADPH are not included in the total equation because there is no net gain or loss!

• Cells transform energy, obtained from the sun, from one form to another through the processes of photosynthesis and respiration.

• The first phase of photosynthesis requires direct light. The green pigment in plants, chlorophyll, absorbs the light and causes chemical changes in the chlorophyll that breaks down water into hydrogen and oxygen. A complicated process follows, the hydrogen and the carbon and oxygen of the carbon dioxide are then converted into compounds that finally result in the stable organic compounds glucose and water. The oxygen is given off as a by-product. Without producers we could not survive, the oxygen they give us is what we breath. We depend on each other to live.

6 CO2 + 6 H2O + energy (from sunlight)       C6H12O6 + 6 O2

Photosynthesis (03:45)

• Reactants = In chemistry, the reactants are the substances that exist at the start of a chemical reaction. During the course of a reaction, the reactants form one or more products. In a chemical equation, the reactant is placed to the left of the arrow:

• Reactant(s) → Product(s) • Carbon Dioxide, Water, & Sun

6 CO2 + 6 H2O + energy (from sunlight)       C6H12O6 + 6 O2

• Products = The substances produced in a chemical reaction.

• Glucose & Oxygen

Photosynthesis (01:42)

• Glucose = A simple sugar that is a major energy source for all cellular and bodily functions.

• Glucose is one of the main products of photosynthesis and starts respiration. The natural form (D-glucose) is also referred to as dextrose, especially in the food industry. The glucose is then converted to starch.

• Glucose is obtained through the breakdown, or metabolism, of food in the digestive system.

• Glucose is the primary fuel used by the brain. • It can also be stored in the liver and muscles in

a polymer form known as glycogen.• A naturally occurring sugar found in fruits and

honey.• Glucose, a simple monosaccharide sugar, is

one of the most important carbohydrates and is used as a source of energy in animals and plants.

C H O6 12 6

• CHLOROPHYLL = The pigment in green plants that absorbs solar energy that is used for photosynthesis.

Plant Structure Related to Photosynthesis

• Chlorophyll looks green because it absorbs red and blue light, making these colors unavailable to be seen by our eyes. It is the green light which is NOT absorbed that finally reaches our eyes, making chlorophyll appear green. However, it is the energy from the red and blue light that are absorbed that is, thereby, able to be used to do photosynthesis. The green light we can see is not/cannot be absorbed by the plant, and thus cannot be used to do photosynthesis.

Plant Structure Related to Photosynthesis

Plants & Minerals• Plants and Minerals• Plants need more than carbon dioxide

and water to thrive. • For healthy growth, plants need

several mineral elements as well. • These elements are dissolved in soil

water and are taken into the roots. For example, nitrogen is taken in through plant roots as nitrate ions, phosphorus as phosphate ions and potassium as potassium ions.

• Fertilizer bags usually carry a code of three numbers such as 10:10:27. These numbers show the amount of the three main nutrients that plants need to survive and grow well. These three nutrients are known as the NPK content.

Mass Of A Plant• In the 17th century a Flemish physician, chemist, and physicist named

Jan Baptista van Helmont performed a 5 year study in which he massed the soil of a willow tree in a pot and after 5 years found that the willow had gained a tremendous amount of mass and soil had lost very little. Van Helmont believed that water was the source of the plant mass.

• John Woodward, a professor and physician at Cambridge University in the late 17th century, tried to design an experiment to test the hypothesis that water was the source of the extra mass. In a series of experiments over 77 days, Woodward had seen the same results as this study and he also rejected the hypothesis that plant growth comes from water.

• It wasn't until 1771 that an English chemist, Joseph Priestly, began to experiment with plants and the air. He made a major breakthrough which led us to the understanding that the plant mass actually does come from the air in the form of carbon dioxide. This fact was not confirmed until 1940 when Martin Kamen discovered carbon-14 which could be used to trace the carbon in carbon dioxide through photosynthesis.

• The answer is actually really simple: Carbon.  Photosynthesis is the act of converting CO2 from the air into O2 and a bit of H2O. 

• Here is a summary of the most important information on photosynthesis:

• Photosynthesis requires: – carbon dioxide – water – light energy– chlorophyll

• Photosynthesis produces: – glucose – waste oxygen

• Photosynthesis is the conversion of: – light energy into chemical energy

• Photosynthesis is essential for: – growth

• Photosynthesis takes place in: Leaves !!!

Low Carbon Dioxide• What would happen to a plant growing in a low carbon

dioxide atmosphere?• Why do greenhouses require a carbon dioxide

generator?

• Please discuss and respond to these questions using scientific data to support your answers.

• RESPIRATION = The process by which oxygen is taken in and used by tissues in the body and carbon dioxide is released.This process produces 38 moles of ATP are derived from the oxidation of 1 mole of glucose, yielding 380,000 cal.

Respiration

Cellular Respiration: Releasing Stored Energy By Breaking Down Glucose (01:29)

Respiration • Respiration is the opposite of photosynthesis. It consumes oxygen

(oxidation of sugars) and releases carbon dioxide (CO2) and water.• Respiration is common to all living organisms, whether plants, animals or

micro-organisms. Respiration enables both autotrophs and heterotrophs to obtain energy from carbohydrates. This energy is necessary for growth, movement and all vital functions.

• Respiration is the metabolic processes whereby certain organisms obtain energy from organic molecules; processes that take place in the cells and tissues during which energy is released and carbon dioxide is produced and absorbed by the blood to be transported to the lungs

ATP

• Respiration transforms energy and matter into usable forms for the organism. (ATP)

• This transformation of energy can be aerobic or anaerobic.• Aerobic = Requires oxygen It occurs in the mitochondrion.

Aerobic respiration is the release of energy from glucose or another organic substrate in the presence of Oxygen. – In our tissues glucose can be broken down to release energy. – The energy is used to make a substance called Adenosine Tri-

Phosphate or ATP as it is usually called. ATP can provide energy for other processes such as muscle contractions.

– ATP is a nucleotide with three phosphate groups instead of one phosphate group. The point of cellular respiration is to harvest chemical energy from food and store it in the chemical bond of ATP.

• Anaerobic = Does not require oxygen, produces less ATP, and produce a by-product of lactic acid or alcohol.

Respiration

Respiration

(Anaerobic)

Respiration • Respiration summary:

– is the release of energy from food – takes place in animal and plant cells.

• Aerobic Respiration requires: – Glucose – Oxygen

• Anaerobic Respiration requires: – Glucose

• Aerobic Respiration produces: – Energy (ATP)– Carbon Dioxide – Water

• Anaerobic Respiration produces: – Energy (not as much) – Carbon Dioxide– Lactic Acid or Alcohol

Glucose + Oxygen = Carbon Dioxide + Water + Energy

ATP: Adenosine tri-phosphate,ATP is a nucleotide with three phosphate groups. The point of cellular respiration is to harvest chemical energy from food and store it in the chemical bonds of ATP.

Plant Respiration • Plants also go through respiration. Plants respire

aerobically.• Photosynthesis feeds respiration. We have

been studying photosynthesis up to now, and you will now find that the products of photosynthesis feed back into a process that releases energy for doing the work within the plant cell, particularly if that cell is not in light or is not one which carries out its own photosynthesis.

• The following are factors that affect respiration in plants:– temperature: respiration falls to a minimum

at temperatures below 0°C, and is at a maximum at 45-50°C;

– the plant's developmental stage : respiration increases during the flowering stage of trees;

– the type of plant: respiration is less significant in woody than herbaceous plants.

• Plants respire both during the day and night. However, photosynthesis takes place during the day only, in the presence of light.

• The main gas exchange surfaces in plants are the spongy mesophyll cells in the leaves. Leaves of course have a huge surface area, and the irregular-shaped, loosely-packed spongy cells increase the area for gas exchange still further.

Plant Respiration

Photosynthesis Compared to Respiration

• Respiration happens 24 hours a day / 7 days a week … Photosynthesis happens only during the daylight.

• Photosynthesis makes food … Respiration uses food.• Photosynthesis makes oxygen from carbon dioxide … Respiration

makes carbon dioxide from oxygen.• Photosynthesis in plants only.

• Photosynthesis uses the energy of sunlight to produce sugars and other organic molecules.

• These molecules in turn serve as food for other organisms. Many of these organisms carry out respiration, a process that uses O2 to form CO2 from the same carbon atoms that had been taken up as CO2 and converted into sugars by photosynthesis. In the process, the organisms that respire obtain the chemical bond energy that they need to survive. However, photosynthesis must have preceded respiration on the earth, since there is strong evidence that billions of years of photosynthesis were required before O2 had been released in sufficient quantity to create an atmosphere rich in this gas to support respiration. (The earth's atmosphere presently contains 20% O2.)

Photosynthesis Compared to Respiration

Photosynthesis Compared to Respiration

Photosynthesis Compared to Respiration

In a nutshell, the comparison is that they both produce chemical energy in the form of ATP (adenosine tri-phosphate), the difference is that in cellular respiration glucose and oxygen are used up and carbon dioxide and water are produced, and in photosynthesis, light and water and carbon dioxide are used and oxygen and glucose are produced.

Cellular respiration - occurs in the mitochondria Photosynthesis - occurs in the chloroplast

Respiration

Photosynthesis

Glucose + Oxygen = Carbon Dioxide + Water + Energy

Carbon Dioxide + Water + Energy = Glucose + Oxygen