Chapter 4 Photosynthesis and Cellular Respiration Worksheets
PHOTOSYNTHESIS & RESPIRATION. Photosynthesis & Respiration Modern Biology –Photosynthesis /...
-
Upload
mariah-chambers -
Category
Documents
-
view
247 -
download
5
Transcript of PHOTOSYNTHESIS & RESPIRATION. Photosynthesis & Respiration Modern Biology –Photosynthesis /...
PHOTOSYNTHESIS & RESPIRATION
Photosynthesis & Respiration
Modern Biology–Photosynthesis / Chapter
6 –Cellular Respiration /
Chapter 7
Energy for Life Processes
• All organisms need energy to survive– Primary source of energy is the sun.
• Energy is the ability to do work… • Work for a cell includes growth & repair,
active transport across cell membranes, reproduction, synthesis of cellular products, etc.
Most organisms need a constant supply of energy.
Energy can be found in many forms.
Energy from the sun is in the form of light energy.
Energy in food is in the form of chemical energy.
Energy for Life Processes
Humpback whales need a lot of energy to leap into the air.
Energy comes fromthe food that they eat.
How much food doyou think a humpbackwhale can eatin one day?
Energy for Life Processes
How do organisms get this energy from the sun?
–PHOTOSYNTHESIS-process used by plants to convert energy from the sun to food (glucose).–RESPIRATION-process that releases energy in food (glucose) to make energy (ATP).
Energy for Life Processes
Autotrophic – “self-feeding”
• Autotrophs or producers convert sunlight, CO2, and H2O into glucose (their food).– This process is called “PHOTOSYNTHESIS”
• Plants, algae, and blue-green bacteria, some prokaryotes, are producers or autotrophs .
Autotrophs
Plants
Algae & some bacteria
Energy for Life Processes
• Only 10% of the Earth’s 40 million species are autotrophs
• Some other autotrophs use inorganic compounds instead of sunlight to make food; process known as chemosynthesis
• Producers make food for themselves and for heterotrophs or consumers that cannot make food for themselves
Heterotrophic – “other-feeding”
• Animals (including humans) represent heterotrophic organisms.
• Since they cannot make their own food, humans and other heterotrophs must get their complex organic compounds by eating plants or other organisms.
Animals and Fungi
Once you eat something, the food gets broken down into ‘nutrients’, or smaller molecules the cells can use.
Some of these molecules are in the form of sugar (glucose). The bonds that hold these molecules together contain energy.
Photosynthesis & Respiration
Cells “absorb” broken food pieces (macromolecules such as protein, nucleic acid, carbohydrates, lipids). In the form of monomers ( building blocks, such as amino acids, glucose & fructose, nucleotides and some smaller pieces of lipids.).
• Cellular respiration is the process that turns food into ATP, a form of energy that our cells can use.
Photosynthesis & Respiration
Energy for Life Processes
Biochemical Pathways
• Photosynthesis and cellular respiration are biochemical pathways
• Biochemical pathways are a series of reactions where the product of one reaction is the reactant of the next
• Only autotrophs are capable of photosynthesis
• Both autotrophs & heterotrophs perform cellular respiration to release energy to do work
Biochemical Pathways
• In photosynthesis, CO2(carbon dioxide) and H2O (water) are combined to form C6H12O6 (glucose) & O2 (oxygen)6CO2+ 6H2O + energy --> 6O2 + C6H12O6
• In cellular respiration, O2 (oxygen) is used to burn C6H12O6 (glucose) & release CO2(carbon dioxide) , H2O (water) and energy
• Usable energy produced in cellular respiration is stored in the chemical bonds of the molecule adenosine triphosphate or ATP
Biochemical Pathways
Photosynthesis
Cellular Respiration
Biochemical Pathways
PHOTOSYNTHESIS
A series of chemical reactions (light & dark
reactions and the Calvin Cycle) where autotrophs capture light energy to make food (glucose).
Chemical Formula:6CO2 + 6H2O + sunlight C6H12O6 + 6O2•Carbon Dioxide water sunlight glucose and oxygen
Leaves: Photosynthetic Factories
• Photosynthesis requires the green pigment chlorophyll.
• The chemical reactions of photosynthesis occur within the chlorophyll-containing organelles called chloroplasts.
• These are found inside cells in plant leaves and stems.
Chloroplasts - membrane bound organelles found in plant and algae cells that absorb light during photosynthesis
They contain:1. the light absorbing pigments2. enzymes for photosynthesis
Light Absorption in Chloroplasts
Light Absorption in Chloroplasts
• Photosynthetic cells may have thousands of chloroplasts
• Chloroplasts are double membrane organelles with the an inner membrane folded into disc-shaped sacs called thylakoids
Light Absorption in Chloroplasts
• Thylakoids, containing chlorophyll and other accessory pigments, are in stacks called granum (grana, plural)
• Grana are connected to each other & surrounded by a gel-like material called stroma
• Light-capturing pigments are found in the grana.
Light Absorption in Chloroplasts
Light Absorption in Chloroplasts
How do chloroplasts absorb light??
LIGHT:
Light travels as waves & packets called photons Wavelength of light is the distance between 2 consecutive
peaks ortroughs
Light Absorption in Chloroplasts
Sunlight or white light is made of different wavelengths or colors carrying different amounts of energy
A prism separates white light into 7 colors (red, orange, yellow, green, blue, indigo, & violet)
ROY G BIV
These colors are called the visible spectrum
Light Absorption in Chloroplasts
The visible spectrum
Each color in a rainbow corresponds to a different wavelength of electromagnetic spectrum.
Light Absorption in Chloroplasts
When light strikes an object, it is absorbed, transmitted, or reflected
When all colors are absorbed, the object appears black
When all colors are reflected, the object appears white
If only one color is reflected (green), the object appears that color (e.g. Chlorophyll)
Thylakoids contain a variety of pigments –molecules that absorbs light - (green, red, orange, yellow...)
Chlorophyll is themost commonpigment in plants & algae
Chlorophyll absorbsonly red, blue, & violet light
Light Absorption and Pigments
Accessory pigments trap wavelengths of light that can not be absorbed by chlorophyll - help capture more light energy
• Carotenoids – reflect orange, yellow, and brown and absorbs green and blue
• Phycobilins – reflect violet & blue and absorb orange, brown and green
Light Absorption and Pigments
Photosynthesis is not a simple one step reaction but a biochemical pathway involving many steps.
This complex reaction can be broken down into two reactions:
1. light dependent (Photosystem I & II, Electron Transport Chain)2. light independent or dark reactions (The Calvin Cycle)
Overview of Photosynthesis
Overview of Photosynthesis
Overview of Photosynthesis
Plants in hot, dry climates use alternate pathways to fix carbon.
Stomata are small openings on the underside of leaves for gas exchange (O2 & CO2)
Plants also lose H2O through stoma so they are closed during the hottest part of the day
Alternate Pathways
The Calvin cycle is the most common pathway used by autotrophs, called C3 Plants.
C4 plants have a clever way of fixing CO 2 during the hottest part of the day when their stomata are partially closed. C4 plants include corn, sugar cane and crabgrass CAM plants include cactus & pineapples
CAM plants open their stomata at night and close during the day so CO2 is fixed at night. During the day, the CO2
is released from these compounds and enters the Calvin Cycle.
Alternate Pathways
Sunlight
CarbonDioxide CO2
Water H2O
Oxygen O2
Leaves: Photosynthetic Factories
PHOTOSYNTHESIS
REMEMBER:This all-important photosynthetic reaction can be summarized by the following chemical equation:
6CO2 + 6H2O + energy (sun) C6H12O6 + 6O2
Factors Affecting Photosynthesis• As with any chemical
reaction, the reactions of photosynthesis can occur at different rates.
• The factors that affect the rate at which photosynthesis occurs are temperature, light intensity, CO2 concentration, availability of water, and the presence of certain minerals.
Factors Affecting PhotosynthesisFor example:Light and CO2: eventually the rate of photosynthesis levels off at a maximum and will not increase any more.
Factors Affecting PhotosynthesisFor example:Temperature: reaches a maximum rate and then decrease until there is NO more photosynthesis.•Why? Enzymes begin to become unstable and ineffective.•Stomata close and limit water loss and CO2 entry.
• Some scientists consider this process of photosynthesis the single most important chemical reaction that occurs on Earth.
• Why?
Science Fact
•Some scientists have a theory about the first cells that appeared on earth about 3.5 billion years ago.
•Early cells had to survive in a harsh environment. ..
•Why do you think photosynthesis might have helped different life forms to appear on Earth?
•In most organisms, two things are needed for cells to get energy: food and oxygen.
•The process by which cells release energy from food is called cellular respiration.
•Cellular respiration is carried out by every cell in both plants and animals and is essential for life.
CELLULAR RESPIRATION
After you eat an apple, your cells are ready to use that stored chemical energy, but
how does this happen?
The release of energy occurs in a series ofenzyme-controlled small steps:
• The energy stored in glucose is convertedinto a usable form, the energy source of all cells, adenosine triphosphate, or ATP. • Cells use the energy from to perform
many functions, such as obtaining materials and eliminating wastes.
• Cellular respiration is basically the opposite of the process of photosynthesis.
• Instead of being produced in the cells, the energy-rich glucose molecules are taken apart to release their stored energy.
• Cellular respiration can be summarized by the following chemical equation:
C6H12O6 + O2 ATP (energy) + H2O +CO2
Sugar + Oxygen ATP (energy) + Water + Carbon dioxide
ATP P P P ADP P P
P
+Energy
ATP --> ADP + P + Energy
Bond is Broken
Partiallychargedbattery
Fullychargedbattery
How do you get energy from ATP?
AEROBIC vs. ANAEROBIC RESPIRATION
In most cells, each molecule of glucose enters into a series of reactions that produce 38 ATP molecules.This process is referred to as aerobic respiration because oxygen is used to help produce the ATP molecules.
AEROBIC vs. ANAEROBIC RESPIRATION
Glycolysis: •the splitting of the glucose molecule; this process yields a small amount of energy as ATP
During anaerobic respiration, energy is released without the use of oxygen. Both Aerobic respiration and Anaerobic respiration begin with glycolysis:
Aerobic respiration continues after glycolysis, through a complex series of chemical reactions called the Krebs Cycle, & Electron Transport Chain. Both of these
reactions take place in the mitochondria of the cell.
The “Mighty” Mitochondria
Anaerobic respiration, also called FERMENTATION, continues after glycolysis, but does not take place in the mitochondria as with aerobic respiration, but in the cytsol.Fermentation occurs when there no oxygen present.
Two types of Fermentation:1.) Lactic Acid-lactic acid is by-product2.) Alcoholic- ethyl alcohol and carbon dioxide are by-products.
Lactic Acid Fermentation Used By:• Some Microorganisms - make yogurt
and cheese• Animals - happens in muscles during
exercise when need more oxygen, but can’t get it. Cause muscle soreness.– Lactic acid transported to liver where
converted to glucose.
Alcoholic Fermentation Used By:• Yeast Cells
– Alcohol in wine and beer is produced this way (carbon dioxide allowed to escape-alcohol stays).
– Bread is also made this way-carbon dioxide produced make bread rise…alcohol evaporate during baking.
800 × 600 - biochemaholic.wordpress.com
AEROBIC vs. ANAEROBIC RESPIRATION
Science Fact
An active cell requires about two million molecules of ATP per second to perform its life functions.
Science Fact
A steady supply of ATP is so critical for life that a poison which attacks any of the proteins used in ATP production kills the organism in minutes. Certain cyanide compounds, for example, are poisonous because they bind to certain atoms which block the system in the mitochondria where ATP manufacturing occurs.
BREATHING vs. Cellular Respiration
Animals move O2 and CO2 into and out of their
bodies by mean of a respiratory system.
The process of breathing, also known as respiration, is controlled by the muscles of the ribs and the diaphragm.
RespirationIn multicellular animals, it is necessary to have breathing or respiration that involves a respiratory system in order to allow the life-sustaining activities of cellular respiration.
• All mammals, including humans, move air into their lungs by lowering the air pressure within them.
• Two sets of structures are involved: the ribs and the muscles between them.
Inhalation ~ FYI ~ Exhalation
When the muscles move the ribs upward and outward, the rib cage expands. At the same time, the diaphragm, a large flat muscle that lies across the bottom of the chest cavity, contracts and moves down. This movement increases the size of the chest cavity and decreases the air pressure in the lungs, so they fill with air.
To move air out, the diaphragm and the muscles between the ribs relax. This movement decreases the size of the chest cavity and increases the air pressure in the lungs, so air moves out.
FYI ~ Gas Exchange Surfaces
• Respiration in all organisms involves the diffusion of gases across cell membranes.• This occurs for plants in the spongy layer of cells within the plants' leaves.• Although gas exchange in animals may involve a complex respiratory system, the actual process of taking in and releasing gases is identical to that of a single-celled organism, such as the ameba.• In other words, gases must cross a barrier to be moved into or out of the animal.
FYI ~ Respiratory Surface
This barrier, a part of the animal's body, is known as the respiratory surface.
• The respiratory surface must remain moist at all times so that gases can diffuse across the cell membranes.• The respiratory surface must be very thin so that gases are able to pass through it.• There must be a source of oxygen, either in the air or dissolved in the water.• The respiratory surface must be closely connected to the transport system that delivers gases to and from cells.
The lining of the alveoli acts as our respiratory surface-it is where gas
exchange occurs in our bodies.
PHOTOSYNTHESIS
CELLULAR RESPIRATION