BIO UNIT Photosynthesis-Cellular Respiration shortversion.ppt

Photosynthesis-Cellular Respiration

1. PHOTOSYNTHESIS
and
RESPIRATION

2. SECTION SECTION 11
PhotosynthesisPhotosynthesis

3. Energy and Living ThingsEnergy and Living Things

PhotosynthesisPhotosynthesis is the process in is the process in
which light energy is converted which light energy is converted
into chemical energy (Glucose). into chemical energy (Glucose).

AutotrophsAutotrophs (plants and some (plants and some
bacteria) use the sun’s energy to bacteria) use the sun’s energy to
carry out carry out photosynthesisphotosynthesis, and are , and are
therefore the foundation of all therefore the foundation of all
living systems.living systems.

6. Breaking Down Food For EnergyBreaking Down Food For Energy

AutotrophsAutotrophs are are
organisms organisms that use that use
energy from energy from sunlight sunlight
or from chemical or from chemical
bonds in inorganic bonds in inorganic
substances to make substances to make
organic compoundsorganic compounds ..

HeterotrophsHeterotrophs are are
organisms that must organisms that must
consume other consume other
organisms as food to organisms as food to
get their energy.get their energy.

7. 
PhotosynthesisPhotosynthesis is the process by which plants, algae, is the process by which plants, algae,
and some bacteria use sunlight, carbon dioxide, and and some bacteria use sunlight, carbon dioxide, and
water to produce carbohydrates and oxygen.water to produce carbohydrates and oxygen.

PhotosynthesisPhotosynthesis has has 3 stages3 stages::
Stage 1Stage 1: : absorptionabsorption of light energy of light energy
Stage 2Stage 2: : conversionconversion of light energy into chemical of light energy into chemical
energy, temporarily stored in energy, temporarily stored in ATP (ATP (adenosine tri phosphate))
and and NADPH (NADPH (nicotinamide adenine di nucleotide phosphate
hydrogen))
Stage 3Stage 3: : storagestorage of chemical energy in of chemical energy in ATPATP and and
NADPH NADPH powers the powers the formationformation of organic molecules of organic molecules

8. 2 stages of photosynthesis2 stages of photosynthesis

Stage 1 Stage 1 –– the Light the Light
ReactionsReactions

Reactants: Light and Reactants: Light and
waterwater

Products: oxygen Products: oxygen
(O(O
22), energy ), energy
molecules molecules ATPATP and and
NADPHNADPH

Location: Location: thylakoid thylakoid
membranesmembranes inside inside
the chloroplastthe chloroplast

9. 2 Stages of Photosynthesis2 Stages of Photosynthesis

Stage 2 Stage 2 –– the the Calvin Calvin
Cycle Cycle (or light-(or light-
independent reactions)independent reactions)

Reactants: carbon Reactants: carbon
dioxide (COdioxide (CO
22))

Products: glucose, Products: glucose,
ADP, NADPADP, NADP
++

Location: Location: stromastroma
inside the chloroplastinside the chloroplast

10. PhotosynthesisPhotosynthesis

PigmentsPigments are light-absorbing substances are light-absorbing substances
that absorb only certain wavelengths of that absorb only certain wavelengths of
light and reflect all others.light and reflect all others.

ChlorophyllChlorophyll is the primary pigment is the primary pigment
involved in photosynthesis. Chlorophyll involved in photosynthesis. Chlorophyll
absorbsabsorbs mostly mostly blueblue and and redred light and light and
reflectsreflects greengreen and and yellowyellow light. light.

This reflection of green and yellow light This reflection of green and yellow light
makes many plants, especially their makes many plants, especially their
leaves, look green.leaves, look green.

11. 
Photosynthesis Photosynthesis
occurs in the occurs in the
chloroplastschloroplasts and and
uses the uses the
pigment pigment
chlorophyllchlorophyll..

12. PhotosynthesisPhotosynthesis

The following chemical equation The following chemical equation
summarizes photosynthesis:summarizes photosynthesis:
66HH
22OO + + 66COCO
2 2 + + light light  CC
66HH
1212OO
66 + + 66OO
22

REACTANTS: REACTANTS: water, carbon dioxide, water, carbon dioxide,
light energylight energy

PRODUCTS: PRODUCTS: glucose, oxygenglucose, oxygen

13. Photosynthesis: Photosynthesis:
Where Does it Occur?Where Does it Occur?
Thylakoid membrane

14. Photosynthesis: Photosynthesis: ThylakoidsThylakoids

ThylakoidsThylakoids are disk-shaped structures found in are disk-shaped structures found in
the the chloroplastschloroplasts of leaf cells that contain of leaf cells that contain
clusters of embedded pigments.clusters of embedded pigments.

These pigment molecules in the thylakoids of These pigment molecules in the thylakoids of
chloroplasts absorb light energy.chloroplasts absorb light energy.

Electrons in the pigments are “excited” by light, Electrons in the pigments are “excited” by light,
and jump from the chlorophyll molecules to other and jump from the chlorophyll molecules to other
nearby molecules in the thylakoid membrane. nearby molecules in the thylakoid membrane.

The series of molecules along the thylakoid The series of molecules along the thylakoid
membrane that excited electrons pass through membrane that excited electrons pass through
as they jump along the chlorophyll molecules is as they jump along the chlorophyll molecules is
called the called the electron transport chainelectron transport chain..

16. Three Factors That Affect Three Factors That Affect
PhotosynthesisPhotosynthesis

1.) amount of light 1.) amount of light – – The rate of photosynthesis The rate of photosynthesis
increases as light intensity increases until all the increases as light intensity increases until all the
pigments are being used. At this saturation point, the pigments are being used. At this saturation point, the
reactions of the Calvin cycle cannot proceed any reactions of the Calvin cycle cannot proceed any
faster.faster.

2.) concentration of carbon dioxide 2.) concentration of carbon dioxide – – Once a Once a
certain concentration of carbon dioxide is present, certain concentration of carbon dioxide is present,
photosynthesis cannot proceed any faster.photosynthesis cannot proceed any faster.

3.) range of temperature 3.) range of temperature – – Like all metabolic Like all metabolic
processes, photosynthesis involves many enzyme-processes, photosynthesis involves many enzyme-
assisted chemical reactions. Unfavorable assisted chemical reactions. Unfavorable
temperatures may inactivate certain enzymes.temperatures may inactivate certain enzymes.

17. SECTION SECTION 22
Cellular RespirationCellular Respiration

18. Cellular RespirationCellular Respiration

Before energy from food can be utilized, it must Before energy from food can be utilized, it must
be transferred to be transferred to ATPATP in a process called in a process called
cellular respirationcellular respiration..

Cellular respiration Cellular respiration is the set of metabolic is the set of metabolic
reactions and processes that take place in the reactions and processes that take place in the
cells of organisms to convert biochemical energy cells of organisms to convert biochemical energy
from nutrients into adenosine triphosphate from nutrients into adenosine triphosphate
(ATP), and then release waste products.(ATP), and then release waste products.

To put it simply, To put it simply, cellular respiration cellular respiration is the is the
process where cells produce energy from process where cells produce energy from
carbohydrates.carbohydrates.

19. Cellular RespirationCellular Respiration

Cellular respiration is the opposite of photosynthesis.Cellular respiration is the opposite of photosynthesis.

The reactants of photosynthesis – carbon dioxide The reactants of photosynthesis – carbon dioxide
and water – are the products of cellular respiration.and water – are the products of cellular respiration.

The products of photosynthesis – glucose and The products of photosynthesis – glucose and
oxygen – are the reactants of cellular respiration. oxygen – are the reactants of cellular respiration.

Cellular respiration releases much of the energy in Cellular respiration releases much of the energy in
food to make food to make ATPATP. .

ATP provides cells with energy they need to carry ATP provides cells with energy they need to carry
out the activities of life.out the activities of life.

20. Cells Transfer Energy Cells Transfer Energy
From Food To ATPFrom Food To ATP

When cells break down food molecules, When cells break down food molecules,
some of the energy is released into the some of the energy is released into the
atmosphere as atmosphere as heatheat, while the rest is , while the rest is
stored temporarily in molecules of stored temporarily in molecules of ATPATP..

Adenosine triphosphate Adenosine triphosphate ((ATPATP) is a ) is a
nucleotidenucleotide with two extra energy-storing with two extra energy-storing
phosphate groups. phosphate groups.

ATPATP molecules are often called the “ molecules are often called the “energy energy
currencycurrency”” of a cell. of a cell.

21. REDRED = = riboseribose (a 5-carbon sugar) (a 5-carbon sugar)
BLUEBLUE = = adenineadenine (a nitrogenous base) (a nitrogenous base)
GREEN = phosphate groupsGREEN = phosphate groups
Adenosine TriphosphateAdenosine Triphosphate

22. ATP Stores and ATP Stores and
Releases EnergyReleases Energy

The energy from The energy from ATPATP is released when the is released when the
bonds that hold the phosphate groups bonds that hold the phosphate groups
together are broken.together are broken.

The removal of a phosphate group from The removal of a phosphate group from
ATPATP (3 phosphates) produces (3 phosphates) produces ADPADP
(adenosine diphosphate -- 2 phosphates), (adenosine diphosphate -- 2 phosphates),
which releases energy in a way that which releases energy in a way that
enables cells to use the energy. enables cells to use the energy.

Cells use energy released by this reaction Cells use energy released by this reaction
to power metabolism.to power metabolism.

23. ATP FYI:ATP FYI:

The human body uses about 1 million The human body uses about 1 million
molecules of ATP per second per cell.molecules of ATP per second per cell.

There are more than 100 trillion cells in There are more than 100 trillion cells in
the human body.the human body.

That is about 1 X 10That is about 1 X 10
2020
, or , or
100,000,000,000,000,000,000 ATP 100,000,000,000,000,000,000 ATP
molecules used in the body each molecules used in the body each
second.second.

24. 
Cellular respiration can Cellular respiration can
be be aerobicaerobic respirationrespiration
(with oxygen) or (with oxygen) or
anaerobic respiration anaerobic respiration
(without oxygen).(without oxygen).

Cellular respiration Cellular respiration
begins in the begins in the cytoplasmcytoplasm, ,
and ends in the and ends in the
mitochondriamitochondria..

25. Aerobic RespirationAerobic Respiration

Respiration that requires oxygen to form Respiration that requires oxygen to form
energy.energy.

Cardio exercises, which involve maintaining a
steady heart rate at 60-80% of one’s maximum,
use aerobic respiration because there is enough
oxygen to sustain muscle power. Sports
activities that use aerobic metabolism include
distance running, swimming, biking, and
jogging.

26. Anaerobic RespirationAnaerobic Respiration

Respiration that does not require oxygen to Respiration that does not require oxygen to
produce energy. produce energy.

Intense workouts and sports activities that use much
energy within short bursts of activity usually require
anaerobic respiration, which provides an immediate
source of power. This process is needed especially
in activities that increase the heart rate beyond 80%
of its maximum. Examples of anaerobic sports
include football, sprinting and wrestling

27. Cellular RespirationCellular Respiration
The chemical formula for The chemical formula for cellular respiration cellular respiration is:is:
CC
66HH
1212OO
66 + 6 + 6OO
22 + + ADPADP + + P P  6 6COCO
22 + 6 + 6HH
22OO + ATP + ATP

REACTANTS: REACTANTS: glucose glucose, , oxygen, oxygen, ADPADP,, extra extra
phosphatephosphate

PRODUCTS: PRODUCTS: carbon dioxide, carbon dioxide, waterwater, , ATPATP

The process summarized by the equation begins in The process summarized by the equation begins in
the the cytoplasm cytoplasm of a cell and ends in the of a cell and ends in the
mitochondriamitochondria..

28. Cellular Respiration: Cellular Respiration: Stage 1 Stage 1
GlycolysisGlycolysis

Stage 1 Stage 1 of cellular respiration isof cellular respiration is called called
glycolysisglycolysis..

GlycolysisGlycolysis is the stage of cellular is the stage of cellular
respiration where glucose is broken down in respiration where glucose is broken down in
the the cytoplasmcytoplasm, converted to pyruvate, and , converted to pyruvate, and
produces a small amount of produces a small amount of ATPATP and and
NADPHNADPH..

GlycolysisGlycolysis – uses – uses 2 ATP2 ATP,, but produces but produces 4 ATP4 ATP
– net gain = – net gain = 2 ATP2 ATP

29. Cellular Respiration: Cellular Respiration: Stage 2Stage 2
The Krebs CycleThe Krebs Cycle

Stage 2 Stage 2 of cellular respiration isof cellular respiration is known as the known as the
Krebs cycle Krebs cycle and is also called and is also called aerobic aerobic
respirationrespiration..

Cellular respiration is called an aerobic Cellular respiration is called an aerobic
process because it requires oxygen.process because it requires oxygen.
CC
66HH
1212OO
66 + 6 + 6OO
22 + + ADPADP + + P P  6 6COCO
22 + 6 + 6HH
22OO + ATP + ATP

A two-carbon molecule combines with a four-A two-carbon molecule combines with a four-
carbon molecule during the Krebs cycle.carbon molecule during the Krebs cycle.

30. Fermentation:Fermentation:
Occurs in the Absence of Occurs in the Absence of
OxygenOxygen

If oxygen (If oxygen (OO
22) is not present in sufficient ) is not present in sufficient
amounts, the mitochondrial membrane cannot amounts, the mitochondrial membrane cannot
function. function.

Energy molecules (Energy molecules (ATPATP and and NADHNADH) cannot be ) cannot be
created in abundance.created in abundance.

So, what does the cell do to continue to break So, what does the cell do to continue to break
down organic compounds and release energy if down organic compounds and release energy if
not enough oxygen is present?not enough oxygen is present?

FERMENTATIONFERMENTATION

31. Production of ATPProduction of ATP
The total amount of The total amount of ATPATP a cell is able to a cell is able to
harvest from each glucose molecule that harvest from each glucose molecule that
enters enters glycolysis glycolysis depends on the depends on the
presence or absence of oxygenpresence or absence of oxygen..
When oxygen is present, When oxygen is present, aerobic respiration aerobic respiration occurs.occurs.
When oxygen is not present, When oxygen is not present, anaerobic respirationanaerobic respiration, or , or
fermentationfermentation,, occurs instead.occurs instead.
FermentationFermentation is the is the anaerobic process anaerobic process that continues the that continues the
breakdown of carbohydrates when there is not enough breakdown of carbohydrates when there is not enough
oxygen for aerobic respiration. oxygen for aerobic respiration.