Unit 3 AP Biology Review Flashcards
Simplified Equation of Photosynthesis
6CO2 + 6H2O + Light energy -> C6H12O6 + 6O2
Proteins that act as organic catalysts
Enzymes
Speed up reactions by lowering the energy (activation energy) needed for the reaction to take place
Catalysts
Substances that enzymes act on
Substrates
Part of the enzyme that interacts with the substrate
Active site
Suggests that the enzyme and the substrate possess specific complementary geometric shapes that fit perfectly
Lock and key model
Describes the active site of an enzyme as specific for a particular substrate that fits its shape
Induced-fit model
When the enzyme and substrate bind together the enzyme is _______ to alter its shape for a _______ active-site substrate attachment
induced, tighter
This tight for places the substrate in a favorable position to react ________ up (____________) the rate of reaction
speeding, accelerating
If those values stray too far from “_______”, the effectiveness of the enzyme will suffer and the enzyme could ________
optimal, denature
The effectiveness of an enzyme can be affected by four things:
- Temperature
- pH level
- Concentration of the substrate involved
- Concentration of the enzyme involved
An inhibitor molecule resembling the substrate binds to the active site and physically blocks the substrate from attaching
Competitive Inhibition
An inhibitor molecule binds to a different part of the enzyme, causing a change in the shape of the active site so that it can no longer interact with the substrate
Noncompetitive Inhibitor
Energy cannot be created or destroyed; it can only change form, and it must be obtained through its environment
First law of Thermodynamics
Life is in a constant movement toward entropy or a “gradual decline of order” in a system and requires a constant input of energy from its environment that can be used to overcome this decline of order
Second law of Thermodynamics
Without the ________ input of energy, the organism will ___
constant, die
Reactions in which energy is absorbed from the surroundings
Endergonic reactions
Reactions in which free energy is released
Exergonic reactions
In an __________ reaction, the products of the reaction contain ____ energy than the reactants, and the extra energy must be _______ for the reactions to proceed
endergonic, more, supplied
In an _________ reaction, the products contain ____ energy than the reactants, and the excess energy is ________
exergonic, less, released
Energy currency of life
ATP
Constructed from an adenosine diphosphate and an inorganic phosphate group (Pi) through phosphorylation
ATP
A chemical process in which a phosphate group is added using free energy
Phosphorylation
Occurs in the cytoplasm of cells
Glycolysis
Beginning pathway for both anaerobic and aerobic respiration
Glycolysis
Starting Materials of Glycolysis
2 ATP
Glucose
6 Carbon
End Products of Glycolysis
2 pyruvate
2 ATP
2 NADH
Also known as the Citric Acid Cycle
Krebs Cycle
Occurs in the matrix of the mitocondria
Krebs Cycle
For each _______ dropped into glycolysis, the Krebs cycle occurs _____
glucose, twice
Starting Materials for the Krebs Cycle
2 oxaloacetate
2 acetyl Co-A
End Products for the Citric Acid Cycle
6 NADH
2 FADH2
2 ATP
2 CO2
(If the cycle were to happen twice)
One molecule of glucose has produced
10 NADH
2 FADH2
4 ATP
Aerobic process in which NADH and FADH2 pass their electrons down the electron transport chain to produce ATP
Oxidative Phosphorylation
The largest energy producing step
Oxidative Phosphorylation
Location is the Mitochondrial Cristae
Oxidative Phosphorylation
Starting Material
NADH
FADH2 (electrons)
End Products of Oxidative Phosphorylation
ATP
The two parts to Oxidative Phosphorylation
Electron Transport Chain and Chemiosmosis
Occurs in the Mitochondrial Inner Membrane
Electron Transport Chain
Starting Materials for Electron Transport Chain
NADH
FADH2
End Products for Electron Transport Chain
H2O
32-34 ATP
- Protons pumped into Inner Membrane space
- Generate proton gradient
Electron Transport Chain
What is the final electron acceptor in the Electron Transport Chain?
Oxygen
The coupling of the movement of electrons down the electron transport chain with the formation of ATP using the driving force provided by a proton gradient
Chemiosmosis
A reaction that uses the product of one reaction as part of another reaction
Coupled reaction
- ATP Synthase uses proton gradient
- Synthesizes ATP
Chemiosmosis
As some of the molecules in the chain accept and then pass on electrons, they ____ ________ ions into the space between the _____ and ____ membranes of the ____________. This creates a ______ ________ that drives the production of ATP
pump hydrogen, inner, outer, mitochondria, proton gradient
The __________ in hydrogen concentration on the two sides of the membrane causes the protons to flow back into the _____ of the ____________ through ATP ________ channels
difference, matrix, mitochondria, synthase
An enzyme that uses the flow of hydrogens to drive the phosphorylation of an ADP molecule to produce ATP
ATP Synthase
____________ is not oxidative phosphorylation but it is a major ____ of oxidative phosphorylation
Chemiosmosis, part
Chemiosmosis is the same process is that occurs in the ____________ during the ATP-creating steps of Photosynthesis
Chloroplasts
- Each NADH -> 3 ATP
- Each FADH2 -> 2 ATP
- 1/2 O2 is the final electron acceptor of the electron transport chain, and the chain will not function in the absence of oxygen
Important things to remember about Oxidative Phosphorylation
Occurs when oxygen is unavailable or cannot be used by the organism
Anaerobic respiration/Fermentation
The process that begins with glycolysis and ends when NAD+ is regenerated
Fermentation
Occurs in fungi, yeast, and some bacteria
Alcohol Fermentation
Occurs in human and animal muscle cells when oxygen is not available
Lactic Acid Fermentation
The host organelle for photosynthesis is the ___________
Chloroplast
Inner fluid portion, surrounded by two outer membranes
Stroma
Flattened channels and disks arranged in stacks
Grana
The stacks in a grana
Thylakoid
An organism that is self-nourishing. It obtains carbon and energy without ingesting other organisms
Autotroph
Cells that are tighty wrapped around the veins of a leaf
Bundle sheath cells
Plant that has adapted its photsynthetic process to more efficiently handle hot and dry conditions
C4 plant
Organisms that must consume other organisms to obtain nourishment
Heterotroph
Interior tissue of a leaf
Mesophyll
Cells that contain many chloroplasts and host the majority of photosynthesis
Mesophyll cells
Process by which water is broken up by an enzyme into hydrogen ions and oxygen atoms
Photolysis
Process by which ATP is produced during the light-dependent reactions of photosynthesis
Photophosphorylation
Process by which oxygen competes with carbon dioxide and attaches to RuBP
Photorespiration
A cluster of light-trpping pigments involved in the process of photosynthesis
Photosystem
A molecule that absorbs light of a particular wavelength. These include chlorophyll, carotenoids, and phycobilins
Pigment
An enzyme that catalyzes the first step of the Calvin Cycle in C3 plants
Rubisco
Structure through which CO2 enters a plant and water vapor & O2 leaves
Stomata
Natural process by which plants lose H2O via evaporation through their leaves
Transpiration
Two set of reactions in Photosynthesis
Light depend reactions
Light independent reactions
Which occurs first?
Light dependent reactions
Input for Light Dependent Reaction
Water and Light
Products for Light Dependent Reaction
Oxygen
NADPH
ATP
Input for Light Independent Reaction
CO2
NADPH
ATP
Products for Light Independent Reaction
Sugar
NADP+
ADP
(The last two for the next light-dependent reactions)
Light reactions occur in the _________ ________
Thylakoid membrane
The oxygen produced in the light reactions comes from ___, not ___
H2O, CO2
Main chlorophyll of Photosystem II absorbs light with a wavelength of ___ nm
680
Main chlorophyll of Photosystem I absorbs light with a wavelength of ___ nm
700
The P in NAPH will remind you of
Photosynthesis
As the electrons are passing from the primary electron acceptor to the next photosystem, ________ ions are picked up from outside the membrane and brought back into the _________ ___________, creating an __ ________ similar to what we saw in oxidative phosphorylation
hydrogen, thylakoid compartment, H+ gradient
The Calvin Cycle occurs in the ______ of the chloroplast
stroma
The Calvin Cycle begins with a step called ______ ________
carbon fixation
The binding of the carbon from CO2 to a molecule that is able to enter the Calvin Cycle
Carbon Fixation
The Calvin Cycle uses more ___ than it does _____. This creates the need for cyclic ____________________ to create enough ATP for the reactions
ATP, NADPH, photophosphorylation
The carbon of the sugar produced in photosynthesis comes from the ___ of the Calvin Cycle
CO2
Consists of pores through which oxygen exits and caron dioxide enters the leaf to be used in photosynthesis
Stomata
The natural process by which plants lose water by evaporation from their leaves
Transpiration
Plants close their stomata during the day, collect CO2 at night, and store the CO2 in the form of acids until it is needed during the day for photosynthesis
CAM photosynthesis
Plants that have adapted their photosynthetic process to more efficiently handle hot and dry conditions
C4 plants
Which of the following molecules can give rise to the most ATP?
A. NADH
B. FADH2
C. Pyruvate
D. Glucose
D
This is because glucose can net 36 ATP
Which of the following is a proper representation of the products of a single glucose molecule after it has completed the Krebs cycle?
A. 10 ATP, 4 NADH, 2 FADH2
B. 10 NADH, 4 FADH2, 2 ATP
C. 10 ATP, 4 FADH2, 2 NADH
D. 10 NADH, 4 ATP, 2 FADH2
D
This also includes glycolysis
Which of the following is an advantage held by a C4 plant?
A. More efficient light absoprtion
B. More efficient photolysis
C. More efficient carbon fixation
D. More efficient uptake of carbon dioxide into the stomata
C
C4 plants are able to successfull perform photosynthesis in these hot areas because of the presence of an enzyme called PEP carboxylase. This enzyme wants to bind to CO2 and is not tricked by the devious oxygen into using it instead of the necessary CO2
Can you continue photosynthesis without a proton gradient?
No, ATP synthase would not be able to work which means ATP would not be formed
