Energy & Enzymes
Cellular Respiration
Photosynthesis
Light reactions and Calvin Cycle
Random
100
What is energy?
The ability to do work
100
What are the 4 steps of cellular respiration in order?
Glycolysis, breakdown of pyruvate, CAC, oxidative phosphorylation
100
Where does the energy to power photosynthesis come from?
Light/solar energy
100
What are photons?
Particles of energy that moves in waves at the speed of light
100
How do enzymes increase reaction rates?
They lower the activation energy of a reaction by stabilizing the transition state
200
An exergonic reaction ______ energy while an endergonic reaction ______ energy.
Releases, requires
200
What step of cellular respiration can occur with or without oxygen?
Glycolysis
200
What is a photoautotroph? Provide an example of one.
An organism that uses sunlight photons' energy to create sugars Ex: Plants, algae, some bacteria
200
How is light energy captured for photosynthesis?
Pigments (chlorophyll and carotenoids)
200
What is the chemical reaction for cellular respiration? Label the redox reactions.
300
Why is ATP high in potential energy?
Repulsion between the negative charges in the phosphate groups
300
Identify the inputs and outputs of the citric acid cycle.
In: 2 Acetyl-CoA, 2 oxaloacetate, 6 NAD+, 2 FADH, 2 ADP + P
Out: 6 NADH, 2 FADH2, 4CO2, 2 ATP, 2 oxaloacetate
300
What is the chemical reaction for photosynthesis? Label the redox reactions.
300
What happens to the electrons of an atom when light is absorbed?
The photons excite the electron and bumps it 2 energy levels, passes energy on (punches neighbor)
300
Identify the inputs and products of oxidative phosphorylation.
In: 10 NADH, 2 FADH2, 6 O2
Out: 30-34 ATP, 6 H2O
400
Explain how allosteric feedback inhibition works.
The final product of the metabolic pathway binds to enzyme 1 and inactivates it by making it undergo a conformation change so substrate 1 can no longer attach to it.
400
What is the purpose of electron carriers throughout cellular respiration?
Electrons get passed through the ETC and fuel active transport of hydrogen ions (low to high) from matrix to intermembrane space
400
Explain how photosynthesis and cellular respiration are connected.
Photosynthesis captures solar energy and stores it in glucose molecules
In cellular respiration, stored energy in glucose is transferred to ATP
ATP is used to power cellular work
400
Explain how ATP is produced during the light reactions (start with pigments absorbing light!)
Pigments in PSII absorb and transfer photon energy to the reaction center
Electrons in P680 chlorophyll a are ejected
Electrons are replaced by water oxidation (water becomes O2)
Ejected electrons enter ETC, pumps H+ low to high into lumen → creates H+ gradient
ATP synthase uses the gradient to make ATP in the stroma
400
Where do the excited electrons from the light reactions ultimately end up?
NADPH
500
What is phosphorylation? How does it work?
Phosphorylation makes endergonic reactions spontaneous by attaching a phosphate group (from the hydrolysis of ATP) to a reactant. This raises the potential energy of the reactants, allowing it to occur spontaneously
500
How is ATP produced through oxidative phosphorylation?
Hydrogen ions flow high to low (facilitated diffusion) through ATP synthase (membrane bound protein), rotates to put P on ADP to make ATP
500
Where does the Calvin cycle occur? What are the inputs and outputs of the step?
Calvin cycle
-Occurs in stroma
6CO2+RUBP→C6H12O6 + RuBP
18 ATP →18 ADP +P
12 NADPH → 12 NADP+
500
What are the 3 steps of the Calvin Cycle? Explain what occurs in each.
Carbon Fixation: 6CO2 are fixed to RuBP by rubisco enzyme
Reduction/sugar production: 12 ATP and 12 NADPH are used to make one glucose
RuBP Regeneration: Left over carbon and 6 ATP used to make RuBP
500
Throughout cellular respiration, how many ATP, NADH, FADH2, CO2, and H2O are produced total?
ATP: 34-38 (2 glycolysis, 2 CAC, 30-34 oxidative phosphorylation)
NADH: 10 (2 glycolysis, 2 breakdown of pyruvate, 6 CAC)
FADH2: 2 from CAC
CO2: 6 (2 breakdown of pyruvate, 4 CAC)
H2O: 6 from oxidative phosphorylation