Bio 131 chapter 4
What is a possible reason for oxygen to be so low by the end of the night?
1.Algae produce oxygen as a by-product of photosynthesis mostly during the day, and not at night. 2.Fish consume oxygen during the night, and oxygen starts to run out by dawn. Both of these explain the low level of oxygen
For what purpose does a plant use the sugars produced during photosynthesis?
1.For cellular respiration to produce ATP 2.For storage 3.For making cellulose, which makes the bulk of a plant
Predict how many molecules of carbon dioxide are produced from the mitochondrial "burning" of one molecule of glucose?
6
Why can't an aerobic bacterium produce as much energy as an animal cell can produce from a gram of sugar?
A bacteria cell is prokaryotic and therefore does not have any mitochondria. Without the inner membrane of the mitochondrion, the bacterium cannot complete the final step of aerobic respiration. The majority of the ATP is not produced until the final step (electron transport chain).
Which of the following is a common energy currency in living cells that powers most living organisms?
ATP
Organize the following steps of the light reaction in order.
Absorb sunlight, split water to release electron, produce oxygen as a by-product, capture energy in ATP and NADPH
Choose the best explanation as to why both consumers and producers perform cellular respiration.
Although they may obtain their sugars in different ways, both consumers and producers rely on cellular respiration to make ATP.
Which processes can be carried out by producers?
Both photosynthesis and cellular respiration
How does ATP release energy that can be used by living cells?
By breaking a bond(phosphate bond) within an ATP molecule
What is the chemical equation for glucose?
C6H12O6
Which process produces glyceraldehyde 3-phosphate (3GP)?
Calvin cycle
What does it mean to "fix" carbon, and during which stage of photosynthesis is carbon fixed?
Carbon is fixed during photosynthesis when it is converted from gaseous carbon dioxide into solid glucose.
Plastids are storage organelles. A chloroplast is a type of plastid. What does a chloroplast store?
Chlorophyll
The chemical reactions of photosynthesis occur in which cellular organelle?
Chloroplasts
What is a photosystem?
Clusters of pigments and proteins that capture light energy
We use energy in many ways. What is one thing we cannot do to energy?
Destroy it
During which stage of cellular respiration is the majority of the ATP produced?
Electron transport chain
Which stage of cellular respiration requires oxygen that you breathe?
Electron transport chain
Identify the stage (or stages) of cellular respiration that occurs entirely outside of the mitochondria.
Glycolysis
Identify the stage of cellular respiration when glucose is split into two molecules of pyruvic acid.
Glycolysis
What color of light is not used for photosynthesis? How could you know this just by looking at a leaf?
Green light is not used for photosynthesis. Green light is the color of light that is reflected instead of absorbed, which is why the leaf appears green. The colors that are absorbed, and therefore not reflected and not seen, are the ones most likely used for photosynthesis.
How do we know green light is not absorbed by chlorophyll?
Green light is the wavelength of light that is reflected instead of absorbed by the chloroplasts.
What is the role of light in photosynthesis?
It energizes electrons
Which of the following statements about heat is false?
It increases the amount of entropy of the system.
Identify the role of oxygen in photosynthesis.
It is a waste product in the light reactions.
Identify the role of carbon dioxide in photosynthesis.
It is split to become incorporated into sugars.
Identify the role of water in photosynthesis.
It is the initial electron releaser when split
What happens to the ATP molecule after it has been used to do work?
It loses a phosphate group and is converted to ADP.
Respiration is called aerobic because ________.
It requires oxygen
Explain why mitochondria are often called "the powerhouse of the cell."
Mitochondria are often called the powerhouse of the cell because they provide energy to the cell in a form the cell can use. The process is similar to how coal burning or hydroelectric or nuclear power plants convert energy from one form into electricity that can be used to power your toaster.
What is the role of chloroplasts in animals?
None, as animals do not have chloroplasts
Alcohol is a waste product produced by yeast in the presence of sugar and the absence of ________.
O2
Which of the following is a waste product of photosynthesis?
O2
Which processes can be carried out by consumers?
Only cellular respiration
Water behind a dam has a certain amount of stored energy that can be released as the water falls over the top of the dam. It may be enough energy to turn a mill wheel or an electricity-generating turbine. Choose the term that best describes the type of energy stored in the water at the top of the dam.
Potential
Predict what would happen as the entropy of a system approaches 100%.
Randomness would become maximized.
Which of the following can carry out photosynthesis?
Seaweeds Bacteria Plants
Which stage of photosynthesis, if any, can function in the dark?
Stage 2 (the Calvin cycle)
The purpose of the Calvin cycle is to produce ________.
Sugar
What is the definition of energy?
The capacity to do work
Why do some leaves change color (red, yellow, orange, etc.) in the fall?
The chlorophyll molecule breaks down and other pigments now become visible.
What molecule(s) link the light reactions (stage 1 of photosynthesis) to the Calvin cycle (stage 2 of photosynthesis)?
The electron shuttles (ATP and NADPH)
Yeast is used to produce beer and wine but can also make bread rise. All of these processes involve the production of alcohol. Explain why you can eat bread and not get drunk.
The heat of cooking bakes out the alcohol.
Select the ultimate source of energy for nearly every organism on this planet.
The sun
Why does yogurt taste sharp?
The taste is from the lactic acid it contains, and acids taste sharp.
Explain how molecules other than glucose can be used as energy sources.
They are modified first and then enter the same metabolic pathway as glucose.
Where do the molecules used as the inputs of the Calvin cycles (ATP and NADPH) come from?
They come from the light reactions.
Identify the principal role of photosynthesis.
To convert solar energy into the chemical energy of sugars
Identify the principal role of cellular respiration.
To convert the chemical energy of sugars into the chemical energy that fuels life's processes
What is the main by-product of cellular respiration?
Water
Which of the following best describes the chemical equation for photosynthesis?
Water + Carbon dioxide + Energy = Sugar + Oxygen
Can energy be harvested by the cells from glucose without oxygen?
Yes, but much less than with oxygen.
Choose the pencil that has the lowest potential energy.
a pencil laying on the ground
Where does cellular respiration occur?
mitochondria
What is the main purpose of cellular respiration?
produce ATP
What is the role of mitochondria in plants?
produce ATP
Name the fluid-filled interior of the chloroplast.
stroma
The bulk of a plant is made from ________.
the sugars made in photosynthesis, which were made from carbon dioxide
How does CO2 enter a plant?
through the stomata
Where do the electrons that are excited by the energy in sunlight first come from?
water
