Cycle 4 BMP Workshop Flashcards
State the relation between:
Growth rate and Enzyme activity
Growth rate = Enzyme activity
State the relation between:
Temperature and Enzyme
Temperature increases, enzyme gains kinetic energy (bumping into one another, bind substrates)
What happens to an enzyme when there is too much thermal energy?
Enzyme denatures
True or False:
The tertiary structure is dependent on primary structure
True
State the relation between:
Primary structure and Temperature
COLD = MORE RIGID = WEAK ARRANGEMENT
HOT = LESS RIGID = STRONG ARRANGEMENT
What is photosynthesis?
- Process performed by autotrophs
- Endergonic (+ΔG): Need light energy
- Redox reaction
Describe:
The redox reaction of photosynthesis
- CO2 is reduced to G3P (used in respiration and other essential processes)
- Water is oxidized to O2 (oxygenetic photosynthesis)
State:
The 2 phases of photosynthesis
- Light-dependent reactions (membrane of thylakoid)
- Calvin cycle (stroma)
What is in the genome of chlorophyll?
Complete transcriptional and translational apparatus (e.x. D1 protein)
What does bacteriorhodopsin do?
Captures light energy to move H+ against its concentration (proton gradient)
This proton gradient is used to produce ATP using ATP synthase
What is bacteriorhodopsin evolutionary similar to?
Channelrhodopsin
How is bacteriorhodopsin processes different from photosynthesis?
- Bacteriorhodopsin directly pumps protons outside cell
- Photosynthesis’ end goal is to produce organic molecules (glucose)
State:
The 8 steps of the Photosynthetic Electron Transport
- Light excites pigment in PSII (P680 to P680 excited)
- P680 excited gets oxidized by donating electron to electron carrier (P680 excited to P680+)
- Movement of electron carrier causing H+ movement across stroma to lumen (proton gradient)
- Electron transferred to PSI and excited by another photon (P700 to P700 excited)
- P700 excited donates electron to electron carrier
- Electron reduces NADP+ into NADPH
- Proton gradient formed creates proton-motive force
- ATP-synthase uses gradient to synthesize ATP
What are Light Dependent Reactions?
A series of redox reactions where electrons are excited by light in the photosystems
The excited state pigment harnesses enough energy to donate electron to electron carrier
State the trend of:
Subsequent electron acceptors and Redox potentials
Each subsequent electron acceptor has an increasing redox potential
State the relation between:
Redox potential and Ability to be oxidized
Negative redox potential = More easily oxidized
What is the purpose of having 2 photosystems?
To bridge the gap between the redox potential
What protein is P680 bound to?
D1
How does P680 pass electrons?
Undergoes redox reactions to pass electrons on to PS1
What would happen to P680 under high intensity light?
P680 excited state accumulates
* Usually steals electrons from water
* Under high intensity, steals electrons from D1
True or False:
Under normal conditions, D1 rate of repair is higher than rate of damage
True, so that D1 levels aren’t full on declining
State:
Location and purpose of Calvin Cycle
Happens in the stroma
Converts CO2 into sugar
What are the 3 important components of the Calvin Cycle?
- Fixation: CO2 fixation onto RuBP by Rubisco which produces PGA
- Reduction: ATP and NADPH reduces PGA to produce G3P (6 G3P)
- Regeneration: RuBP is regenerated from remaining 5 G3P
How much G3P is made from the Calvin Cycle? How much is needed for glucose formation?
Every three turns, produces one G3P
2 G3P = 1 molecule of glucose
How is oxygenic photosynthesis different from anoxygenic photosynthesis?
Oxygenic photosynthesis uses WATER instead of H2S to donate electrons
True or False:
Water requires 1 photosystem to be fully oxidized
False, water needs 2 photosystem to be fully oxidized
Define:
Anabolic reaction
Energy is required to build larger molecules from smaller ones (e.x. Amino acid to protein synthesis)
Endergonic (+ΔG)
Define:
Catabolic reaction
Energy is released from energy rich molecules to obtain smaller molecules from larger ones (e.x. cellular respiration)
Exergonic (-ΔG)
True or False:
Endergonic reactions can occur in the cell
False, endergonic reactions DO NOT occur in the cell
Describe:
Energy Coupling
Exergonic pathway is spontaneous
Endergonic reactions require ATP to occur
Can couple “endergonic” reactions with ATP hydrolysis reaction
What happens in substrate level phosphorylation? When does it occur?
- ADP receives phosphate group from high-energy molecule/substrate, forming ATP
- Occurs during the glycolysis (2 ATP net produced) and citric acid cycle (1 ATP produced from GTP)
State:
The reactants and products of glycolysis
- Reactants: Glucose, ATP, ADP, NAD+
- Products: ATP, NADH, Pyruvate
Amounts: 1 Glucose produces 2 ATP + 2 NADH + 2 Pyruvate
(Requires 2 ATP per glucose molecule, produces 4 ATP, thus net production is 2 ATP)
State:
The reactants and products of Pyruvate oxidation
- Reactants: Pyruvate, NAD+, Coenzyme A (CoA SH)
- Products: CO2, NADH, Acetyl Coenzyme A (Acetyle CoA)
1 Pyruvate = 1 CO2 + 1 NADH + 1 Acetyl CoA
State:
The reactants and products of the Citric Acid Cycle
- Reactants: Acetyl CoA, NAD+, GDP, Phosphate, FAD
- Products: CoA, NADH, CO2, GTP, FADH2
1 Acetyl CoA = 3 NADH + 1 FADH2 + 2 CO2 + 1 GTP + 1 CoA
What happens in oxidative phosphorylation?
Converts free energy from NADH and FADH2 into ATP
State:
The 2 components of oxidative phosphorylation
- Electron Tranport Chain
- Chemiosmosis
For the electron transport chain, state:
- Type of process
- Where electrons come from
- How cofactors are organized
- Oxidative process
- Received from NADH and FADH2
- Organized from most negative to most positive redox potential (most easy to oxidize to most easy to reduce)
How many cofactors/complexes are involved in the electron transport chain?
4
What is the terminal electron acceptor in the electron transport chain? Why?
Oxygen, it has the highest affinity for electrons out of all cofactors
What is the purpose of the electron transport chain?
The energy released from the electrons is used to drive proton pumping (proton gradient)
What is chemiosmosis?
- A phosphorylation process
- ATP synthase uses proton gradient to synthesize ATP
True or False:
In the electron transport chain, the protein complexes are being reduced
False, the protein cofactors are being reduced NOT the protein complexes themselves
True or False:
ATP is a product of the electron transport chain
False, ATP is a product of chemiosmosis NOT a product of the electron transport chain
What is the product of the electron transport chain?
Water
(Protons are pumped out at each protein complex to form a proton gradient)
State the relation between:
Electron Transport Chain and Chemiosmosis
Electron transport chain helps build the proton gradient to drive the proton motive force required during chemiosmosis
What is the only place that protons can pass through to return to the matrix?
ATP synthase
Why are protons used in oxidative phosphorylation?
There is a concentration difference and electric charge difference, which means a TON OF ENERGY
What do uncouplers do?
Produce holes in the membrane, allow H+ protons to pass back through the membrane
State:
The consequences of uncoupling
- Free energy not conserved
- Energy lost as heat
- Disrupts ATP synthesis
Babies and hibernating bears have higher expression of protein uncoupler
What forms of uncouplers are there?
Protein uncouplers
Chemical uncouplers
State:
Function of Pyruvate dehydrogenase complex
Brings pyruvate into the mitochondria under normal O2 conditions (sufficient oxygen)
State:
Function of Pyruvate dehydrogenase kinase
Blocks pyruvate dehydrogenase complex at low levels of O2
What results from pyruvate dehydrogenase kinase activation?
- Upregulation of glycolysis and fermentation to maximize ATP production
What happens to pyruvate when pyruvate dehydrogenase kinase is activated?
Instead of pyruvate oxidation (aerobic respiration), it undergoes lactate or ethanol fermentation to generate ATP (anaerobic respiration)
What is the difference in ATP production for aerobic and anaerobic respiration?
- Aerobic respiration uses oxidative phosphorylation, creating around 36 ATP/1 glucose
- Anaerobic respiration relies on glycolysis and fermentation, creating only 2 ATP/1 glucose
What is the Citric Acid Cycle also known as?
Kreb’s Cycle
What is the Warburg effect?
Aerobic glycolysis
* Expressed in cancer cells
* Active pyruvate dehydrogenase kinase no matter how much O2
What are the effects of the Warburg effect?
- Increased activity of glucose transporters
- Increased activity of hexokinase
- Less ATP produced (4 ATP/1 glucose)
Where does anaerobic respiration occur?
In the cytosol
Where does the citric acid cycle and oxidative phosphorylation occur?
In the mitochondria
What enzyme converts glucose to pyruvate?
Hexokinase
