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Homework 7 Due 11/12
What is ATP? What is ADP? Give similarities and differences between the two molecules.
Photosynthesis and Cellular Respiration
ALL CELLS REQUIRE ENERGY
Some chemical reactions release energy (what kind of rxn?) while others absorb energy
All chemical reactions consume activation energy
All cells require energy to perform processes
This is a requirement of life!
Two ways to get food
“troph” = food (nutrition)
Autotrophs– Auto = self– Autotrophs make their own food
Heterotrophs– Hetero = different– Heterotrophs get their food from something else (they
have to eat it)
Two ways to get food
Autotrophs– Producers– Plants, algae, some bacteria
Heterotrophs– Consumers– Animals, fungi, most protists most bacteria– (do you remember the vore terms?)
Cellular Respiration
Cells Breathing
Cellular Respiration
Happens in all cells. Yes both plant and animal cells
Overall Reaction:– C6H12O6 + 6O2 → 6CO2 + 6H2O + 36 ATP
Occurs in Cytoplasm and Mitochondria
Homework 7 Due 11/12
What is ATP? What is ADP? Give similarities and differences between the two molecules.
ATP – when a PO4 is removed, energy is released!
What kind of reaction is this?
Some energy is given off as heat.How would you get back to ATP?
Which comparison between ATP and ADP is correct
A. ATP stores less chemical energy than ADP and phosphate
B. ATP stores more chemical energy than ADP and phosphate
C. Less energy is used to form ATP than is released from ATP and hydrolysis
D. More energy is used to form ATP than is released from ATP and hydrolysis
Which comparison between ATP and ADP is correct
A. ATP stores less chemical energy than ADP and phosphate
B. ATP stores more chemical energy than ADP and phosphate – which is released! This is it!
C. Less energy is used to form ATP than is released from ATP and hydrolysis – NO, it would be the same
D. More energy is used to form ATP than is released from ATP and hydrolysis – see above
A protein in a cell membrane changed its shape to move sodium and potassium ions against their concentration gradients. Which molecule was most likely used by the protein as an energy source?
A. ATP
B. ADP
C. Catalase
D. Amylase
A protein in a cell membrane changed its shape to move sodium and potassium ions against their concentration gradients. Which molecule was most likely used by the protein as an energy source?
A. ATP – Ummm… yeah!
B. ADP – nope, no energy
C. Catalase – nope enzyme (peroxide)
D. Amylase – nope enzyme (digestion)
RESPIRATION
Process of taking ADP and making it ATP again. Involves breaking down
Complicated molecules into simple molecules
Cellular Respiration Overview
Depends on whether or not there is oxygen
Aero = oxygen Aerobic Respiration – makes energy IN O2
Anaerobic Respiration – Fermentation – makes energy WITHOUT O2
3 Stages of aerobic cellular respiration
1. Glycolysis
2. Krebs Cycle
3. Electron Transport System
For each glucose molecule, total ATP = 36
Only 39% efficient, rest is lost as heat.
HOMEWORK 8 – DUE 11/19
Describe the energy changes occurring in each process of photosynthesis.
Describe how energy transformations involved in photosynthesis are related to energy transformations involved in cellular respiration.
Step 1: Glycolysis
Glycolysis makes 2 molecules of ATP (energy) Glycolysis happens in the cytoplasm of the cell Glycolysis is anaerobic Glucose is broken down into smaller molecules
Step 1a: Check for Oxygen
If oxygen is present, two more steps occur in the mitochondria
If no oxygen is present, fermentation occurs Let’s go on as if there IS oxygen
Mitochondria
In ALL eukaryotic cells! (name some. What is NOT?)
Are not original to cells. Most likely a prokaryote of their own Have their own DNA and Ribosomes They take shelter in cells, and in return provide
ATP (cell currency) to their hosts.
Mitochondria Structure
The outer membrane to protect the organelle The intramembrane space (the space between
the inner and outer membranes) The inner membrane is folded into a series
cristae or long folds that greatly increase the surface area of the inner membrane allowing more area for energy production in electron transport.
The matrix – inside the inner membrane
Steps 2 with oxygen:Kreb’s Cycle
Kreb’s Cycle aka citric acid cycle Takes place in matrix Breaks down PRODUCTS from glucose Produces much CO2
Produces 2 ATP
Kreb’s Cycle (Citric Acid Cycle)
Steps 3 with oxygen: Electron Transport Chain
Electron Transport Chain – makes 32-34 ATP H+ ions, FADH2 and NADH are used here. These ions flow across the inner mitochondria
membrane As they flow, they power ATP synthase (sits on
inner membrane) This enzyme attaches PO4 to ADP, making ATP
Energy Tally AEROBIC
36 ATP for aerobic vs. 2 ATP for anaerobic
– Glycolysis 2 ATP
– Kreb’s 2 ATP
– Electron Transport 32 - 34 ATP 36 - 38 ATP
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon
Step 2 without oxygen: Fermentation
The cell must recycle the materials from glycolysis. DOES NOT GIVE AS MUCH ATP.
This recycling process is called fermentation. The product of fermentation is alcohol (ethanol)
and carbon dioxide (prokaryotes) OR lactic acid (for us).
Which types of respiration are useful in increasing the amount of gas in a food product?
A. Fermentation producing lactic acid only
B. Fermentation producing carbon dioxide and ethanol only
C. Aerobic respiration and fermentation producing lactic acid
D. Aerobic respiration and fermentation producing carbon dioxide and ethanol
Which types of respiration are useful in increasing the amount of gas in a food product?
A. Fermentation producing lactic acid only – need CO2
B. Fermentation producing carbon dioxide and ethanol only YES THIS IS IT
C. Aerobic respiration and fermentation producing lactic acid
D. Aerobic respiration and fermentation producing carbon dioxide and ethanol
All of the following are correct about respiration except
A. All plants and animals carry out respiration all the time
B. It consists of glycolysis, Krebs cycle, and the electron transport chain
C. Oxygen molecules are pumped across the inner membrane of the mitochondria
D. Most ATP is produced in the electron transport chain
All of the following are correct about respiration except
A. All plants and animals carry out respiration all the time
B. It consists of glycolysis, Krebs cycle, and the electron transport chain
C. Oxygen molecules are pumped across the inner membrane of the mitochondria – nope, it’s H+
D. Most ATP is produced in the electron transport chain
Glycolysis
A. Produces water
B. Produces oxygen
C. Involves an electron transport chain
D. Is the breakdown of glucose to produce smaller organic compounds
E. Produces carbon dioxide
Glycolysis
A. Produces water
B. Produces oxygen
C. Involves an electron transport chain
D. Is the breakdown of glucose to produce smaller organic compounds
E. Produces carbon dioxide
Photosynthesis
HOMEWORK 8
Describe the energy changes occurring in each process f\of photosynthesis.
Describe how energy transformations involved in photosynthesis are related to energy transformations involved in cellular respiration.
Used by producers to create glucose
Reactants are 6 carbon dioxide and 6 waterCreates 1 glucose moleculeGlucose can be stored (?), used as
structure (?), or directly in respirationSome ATP is also directly produced
Though respiration occurs, more O2 is generated than used
Which of the following best explains the relationship between photosynthesis and cellular respiration?
A. Both produce CO2 and O2
B. Both require energy from sunlight to occur
C. The products of one are the reactants of the other
D. A plant can carry out one or the other process
Photosynthesis
Takes place in specialized structures inside plant cells called chloroplasts
Chloroplasts surround the central vacuole (water storage) of the plant cell. Why?
Photosynthesis
Chloroplasts are one of the special structures in plants.
Chloroplasts are almost certainly cyanobacteria that have hopped into plant cells for a symbiotic ride.
They get a home, the plant gets sugar. What relationship is this?
Chloroplast –vs- Mitochondria
• Both are surrounded by a double membrane with an intermembrane space.
• Both have their own DNA . • Both are involved in energy metabolism. • Both have membrane reticulations filling
their inner space to increase the surface area on which reactions with membrane-bound proteins can take place.
Structures of chloroplasts
Double membrane surrounds stroma – inner fluid Stacks of disks called thylakoids Thylakoids contain chlorophyll – a pigment that
absorbs light energy.
Light is absorbed by pigments
The primary pigment for photosynthesis is chlorophyll a
It absorbs blue and red light, not green (green light is reflected back!)
Absorption spectrumof chlorophyll a
Chlorophyll a is the primary photosynthetic pigment that drives photosynthesis.
Accessory pigments absorb at different wavelengths, extending the range of light useful for photosynthesis.
Leaves are where most photosynthesis occurs
Leaves need direct access to CO2 and H2O They take these in from atmosphere through
stomata Plants can open stomata to take in CO2 and
release O2 (plural is stoma) Plants also take in water through roots which
travels to leaves through vascular tissue called xylem.
Chloroplast Structure & Function
The chloroplast has different spaces: stroma and thylakoid
These compartments and the membranes that separate them serve to isolate different aspects of photosynthesis. Light reactions take place on the thylakoid
membranes. “Dark” reactions take place in the stroma.
Inside a Chloroplast
• Remember: Structure correlates to function!
Homework 9 Due 11/25
• When temperature becomes too warm, leaves close their stoma to conserve water. How will high temperature most likely affect rate of photosynthesis?
• In the autumn, the amount of daily sunlight decreases in time and strength. Additionally, the amount of water in the air decreases with temperature. Explain how deciduous trees cope with the winter season.
Photosynthesis
• 2 different reactions– Light Reactions
• Capture light energy for photosynthesis
– Calvin Cycle• Produces glucose
sugar
The first stage – Light Dependent
1. Occur in Thylakoid – why?
2. Uses chlorophyll to split H2O
3. Captures sun energy
4. Produces ATP and other energy rich molecules
5. Splits water (H needed for next stage and O2)
6. Release O2 from leaf
Using a microscope, a student observes a small, green organelle in a plant cell. Which energy transformation most likely occurs first within the organelle
A. ATP to light
B. Light to Chemical
C. Heat to electrical
D. Chemical to chemical
Using a microscope, a student observes a small, green organelle in a plant cell. Which energy transformation most likely occurs first within the organelle
A. ATP to light
B. Light to Chemical of course. Come on.
C. Heat to electrical
D. Chemical to chemical
The second stage – Light Independent
1. The “Dark” or Carbon Reactions
2. Also called Calvin Cycle
3. Light independent (can occur in light or dark; some enzymes require activation by light)
4. Occurs in stroma
5. Uses the energy from stage 1 (ATP; NADPH) to “fix” carbon in sugar
Photosynthesis and cellular respiration are two major processes of carbon cycling in living organisms. Which statement correctly describes one similarity between photosynthesis and cellular respiration?
A. Both occur in animal and plant cells
B. Both include reactions that transform energy
C. Both convert light energy into chemical energy
D. Both synthesize organic molecules as end products
Efficiency & Photosynthesis
Photosynthesis is not perfect. Depending upon the plant type, it ranges
from being only 1 - 4 % efficient to having 7% efficiency
Without photosynthesis, virtually all plants and animals would become extinct.
Photosynthesis Respiration
• Reaction: CO2+H2O+sunC6H12O6+O2+H2O C6H12O6+O2CO2+H2O+36ATP
• Reactants: Carbon dioxide, water, sun Glucose, oxygen
• Products: Glucose Energy• By-products: Oxygen Carbon dioxide,
water• Cellular location: Chloroplasts Cytoplasm, mitochondria
• Energetics: Requires energy Releases energy
• Chemical paths: Light reactions & Glycolysis, Krebs cycle Calvin cycle & Electron Transport
Syst.
• Summary: Sugar synthesized using Energy released from energy from the sun sugar breakdown
The oxygen that plants give off
A. Comes from the light dependent reactions
B. Comes from the dark reactions
C. Is a by-product of respiration
D. Comes from CO2 that plants absorb
E. Is carried from the Calvin cycle to the light reactions.
The oxygen that plants give off
A. Comes from the light dependent reactions
B. Comes from the dark reactions
C. Is a by-product of respiration
D. Comes from CO2 that plants absorb
E. Is carried from the Calvin cycle to the light reactions.
Name as Light Dependent or Independent
A. Oxygen released - DEPENDENT
B. Carbon fixation occurs - INDEPENDENT
C. Calvin Cycle occurs - INDEPENDENT
D. ATP produced - DEPENDENT
Which is produced by both respiration and photosynthesis?A. Glucose
B. ATP
C. CO2
D. O2
Which is produced by both respiration and photosynthesis?A. Glucose
B. ATP
C. CO2
D. O2
Respiration, Energy & Carbon Cycle
• Energy• Virtually all organisms require energy of
food for:• Making chemicals
(proteins, carbs, etc.)• Movement• Cell division• Heat, electricity and light production
• The way living organisms obtain energy is throughCell respiration
ENERGY: ability to do workNewton’s First Law of Thermodynamics:
“Energy cannot be created or destroyed, it can only be transformed
from one form to another”
• Once a cell has used energy to do work, it cannot be used again by any organism.
(1701)
ENERGYENERGY FLOW IS LINEARSun Earth Producers 1o consumers 2o consum
heat resp, heat resp, heat resp, heat
Energy flows into ecosystem from the sun
Energy travels in a straight line by way of
food chains.
ENERGYHowever, much energy is lost as heat along
the way – as a result of respiration.
Approximately 90% energy is lost on each step!
• Newton’s Second Law of
Thermodynamics:
“In any transfer of energy there is always a loss of useful energy to the system,
usually in the form of heat”
Food ChainsFood chains demonstrate linear nature of
energy• Producers are the base of the food chain,
they include photosynthetic organisms like:• Plants• Algae• Certain bacteria
Food chains• Primary
consumers – all plant eaters (herbivores).
Secondary consumers – Eat primary consumers, (carnivores)
Food chains
• Decomposers – aka detritivores - obtain energy by breaking down remaining organic material of the other members of the food chain.
• Fungi and bacteria.
Matter• All important elements move in cycles;
Environment Organisms
Cycles called biogeochemical cycles:
Water cycle
Carbon cycle
Nitrogen cycle
The Carbon Cycle• Carbon from the atmosphere (CO2) enters the
biosphere by way of plants!– CO2 used in photosynthesis
– Carbon moves into food chain • Carbon is released to the physical
environment by respiration – Release CO2 during respiration
– Amount CO2 fixed in photosynthesis = the amount released by respiration
Carbon Cycle• Carbon moves from atmosphere to
plants to animals and back to atmosphere.
Venus doesn’t have a carbon cycle. It’s hell.
“Look deep into nature, and then you will understand everything better.” Albert Einstein
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