Transcript PLANTS - Weebly

Standard 3
Interdependence of Living
Systems and the Environment
Unit 3 - Photosynthesis & Respiration
6 CO2 + 6 H2O + energy (from sunlight)
C6H12O6 + 6 O2
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.
H2O
+
→
+
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.
Plant Structure Related to Photosynthesis
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
• 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.
Plant Structure Related to Photosynthesis
• 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.
• 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.
Oak (Quercus robur) branch sectioned to show
xylem tubules arranged in growth rings.
The picture of magnified spruce wood above
clearly shows the staw-like fibers of xylem.
• 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.
Light Reaction
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
• Water
• Products =
• Oxygen
• NADP+
• High Energy ATP
• ADP
• High Energy
NADPH
• Reactants =
• Phosphorus
http://www.youtube.com/watch?v=hj_WKgnL6MI&noredirect=1
Light Reaction
H2O + light + NADP+ + ADP + P
http://www.johnkyrk.com/photosynthesis.html
O2 + NADPH + ATP
Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)
CO2 + NADPH + ATP
C6H12O6 + NADP+ + ADP + P
• 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
Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)
CO2 + NADPH + ATP
C6H12O6 + NADP+ + ADP + P
• Key Terms
• Dark reaction / Calvin Cycle / Calvin-Benson Cycle
• ATP / ADP
• NADPH / NADP+
• Carbohydrate production / organic molecule production
Dark Reaction (aka Calvin Cycle, Calvin-Benson Cycle)
CO2 + NADPH + ATP
• Reactants =
• Carbon Dioxide
• NADPH
• ATP
C6H12O6 NADP+ + ADP + P
• Products =
• Glucose
• ADP
• NADP+
• Phosphorus
Light + Dark Reaction
6 CO2 + 6 H2O + energy (from sunlight)
C6H12O6 + 6 O2
• Carbon Dioxide (low
energy compound)
• Products =
• Glucose (high
energy compound)
• Water
• Oxygen
• Reactants =
• 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.
Photosynthesis (03:45)
6 CO2 + 6 H2O + energy (from sunlight)
C6H12O6 + 6 O2
6 CO2 + 6 H2O + energy (from sunlight)
C6H12O6 + 6 O2
• 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
• 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.
C6 H12 O6
Plant Structure Related to Photosynthesis
• 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.
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
• 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.
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
• 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 TriPhosphate 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
(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
ATP: Adenosine triphosphate,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.
Glucose + Oxygen = Carbon Dioxide + Water + Energy
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.
Plant Respiration
• 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.
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 Compared to Respiration
• 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
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
Photosynthesis
Carbon Dioxide + Water + Energy = Glucose + Oxygen
Glucose + Oxygen = Carbon Dioxide + Water + Energy
Respiration