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69 terms

bio exam 3 farr

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What type of reaction breaks down the bonds that join the phosphate groups in an ATP molecule?
hydrolysis (involves breaking bonds with the addition of water)
The most common energy carrier molecule in living organisms is:
ATP
A "high energy" bond in an ATP molecule is located between:
two phosphate groups
Which molecule functions in the short term storage of energy?
adenosine triphosphate
most enzymes are ______.
proteins
enzymes work by ______.
reducing EA (energy of activation)
an enzyme ______.
is an organic catalyst (enzymes are proteins that behave as catalysts)
What name is given to the reactants in an enzymatically catalyzed reaction?
substrate
As a result of its involvement in a reaction
an enzyme ______.,is unchanged
Which of the following lowers the activation energy of a biochemical reaction?
catalysts
Which of the following functions as a biological catalyst?
enzyme
animals have enzymes that break apart starch molecules but not cellulose
despite the fact that both are made up of glucose subunits. Which enzyme characteristic BEST explains this?,Enzymes are highly specific
What is the ultimate source of energy for almost all forms of life on earth?
solar energy
Most enzymes do not work if the temperature is raised too much. Why is this?
enzymes denature at higher temperatures (incorrect temperature, pH, and salt concentrations cause an enzyme to change shape)
The metabolism of a cell is the sum of all its chemical reactions. True or False?
True
energy that is not converted to useful energy is usually given off as:
heat
Which of these equations best summarizes photosynthesis?
6 CO2+6 H20 --> C6H12O6+6 O2
The light reactions of photosynthesis use ____ and produce ____.
water....NADPH (during the light reactions, water is split to produce oxygen. Excited electrons from water join with NADP+ to produce NADPH
What is the purpose of a cuticle on a leaf?
to prevent water loss (the was cuticle makes the leaf waterproof, to preven water from leaving by evaporation. The oil on your skin performs a similar function)
How is O2 involved in photosynthesis?
O2 is a product of the light reactions. (O2 is produced when water is consumed in the light reactions.)
Before photosynthesis evolved
_____ was rare in the earths atmosphere.,O2
The products of photosynthesis are:
glucose and oxygen
All of the following compounds are necessary constituents for photosynthesis EXCEPT:
NADP
The cellular organelle that is responsible for photosynthetic activity is the:
chloroplast
_____ has a longer wavelength than ______.
Red....green
You place a plant in a transparent box made of greenish-yellow plastic. How does this affect photosynthesis for the plant?
None of the plant pigments will be able to absorb the light. Photosynthesis will stop. (none of the major pigments absorb at this wavelength)
Why do plants leaves appear green?
the chlorophyll in leaves reflects green light
Why do plants produce O2?
because O2 is produced as a by-product when the plant creates H+ ions and free electrons from water
Where are the electrons used in a photosystem II found at the very end of the light reactions?
in NADPH (the electrons and a few of the hydrogen ions released from water in photosystem II are bound to NADP+ to form molecules of NADPH)
The energy source in photosynthesis is:
visible light
Suppose that you are experimenting with different types of lighting for your indoor green plants. Which of the following colors of light will be most effective?
red-blue
Light reactions produce:
ATP, NADPH, and O2
Where does the O2 released during photosynthesis come from?
H2O
During the process of photosynthesis
solar energy is converted to:,chemical energy
The light reactions of photosynthesis result in which of the following?
synthesis of ATP
The energy of the movement of electrons down a concentration gradient via electron transport within chloroplasts and mitochondria is used to generate molecules of:
ATP
Suppose you are studying photosynthesis in a research lab. You grow your plants in a chamber with a source of water that has a radioactively labeled oxygen atom. What photosynthetic product will be radioactive?
O2 gas
The NADPH required for carbon dioxide fixation is formed:
during the light reactions
The primary function of the light reactions of photosynthesis is to:
produce energy-rich ATP and NADPH
Which of the following provides O2 as an end product?
light reaction
why do chloroplasts make energy carriers during the light reactions?
to provide energy for the synthesis of sugar. (sugar synthesis is endergonic and requires the energy in ATP and NADPH to proceed)
What structural feature of a leaf enables it to obtain CO2 from the air?
stomata
All of the following factors influence the rate of photosynthesis EXCEPT:
atmosperic N2 levels
All of the following compounds are necessary constituents for photosynthesis EXCEPT:
oxygen
The pigment(s) that absorb light energy to drive photosynthesis is/are:
chlorophyll and carotenoids
The ATP and NADPH synthesized during the light reactions are:
dissolved in the stomata
Carbon fixation involves the addition of carbon dioxide to _____.
RuBP (in the calvin cycle, carbon dioxide is added to RuBP)
after 3-PGA is phosphorylated
it is reduced by _____.,NADPH
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?
6 (6 carbon dioxide molecules are required to produce two G3P molecules, which can be combined to make one glucose molecule)
in the calvin cycle
how many ATP molecules are required to regenerate RuBP from five G3P molecules?,3
In which of the following organelles does photosynthesis take place?
chloroplast
What connects the two photosystems in the light reactions?
an electron transport chain
What two molecules are produced by the light reactions and used to power the calvin cycle?
ATP and NADPH
What provides electrons for the light reactions?
H20
What provides the carbon atoms that are incorporated into sugar molecules in the calvin cycle?
Carbon dioxide (CO2)
what transports electrons from the light reactions to the calvin cycle?
NADPH
The light reactions take place in the _______ and the calvin cycle takes place in the ______.
Thylakoids; stroma
The term "cycle" is used to describe the calvin cycle because:
the process begins and ends with RuBP
Which of the following occurs during the calvin cycle of photosynthesis?
carbon dioxide is converted to chemicals that can be used to make sugars.
In the C3 pathway
where does the carbon come from to form glucose?,atmospheric CO2
Which of the following is NOT true of chlorophyll?
it is found in mitochondria
The role of water in photosynthesis is to:
provide electrons
The energy of the movement of electrons down a concentration gradient via electron transport within the thylakoid membrane is used to generate:
ATP
Many plants have evolved leaves that have adjustable pores
called ______, which allow for gas exchange and water loss.,stomata
Carbon dioxide is required in the light reactions of photosynthesis. True or False?
False
Which of the following is a source of electrons that green plants use for reduction reactions?
H2O
Glucose synthesis during photosynthesis requires that:
the products of energy-capturing reactions must be available
All of the following are part of the Calvin cycle EXCEPT:
generation of ATP
ATP is required during which of the following reactions?
The calvin cycle only