Exam 3 Flashcards
What do enzymes do?
speed up processes by lowering activation energy
How do enzymes do their job?
-positioning substrate for reaction
-stressing it out to be more reactive
-providing optimal environment for subtrate
What is competitive inhibtion?
beating the substrate to active site
What is noncompetitive inhibition?
binding somewhere other than the active site closing the active site, not allowing the substrate to bind to active site
What happens in allosteric regulation when it’s active?
they bind somewhere other than active site, keeping it on
What happens in allosteric regulation when it’s inactive?
bind somewhere other than active site keeping it off
what does positive feedback do?
speed up process
what does negative feedback do?
slow down/ turn off process (no more needed)
What is the effect of temperature and pH on enzymatic activity?
there is an optimal pH and temperature, cannot be too high or too low.
Name the principles of metabolic pathways
- Complex chemical reactions occur in a series of separate, intermidiate reactions that form a metabolic pathway
- Each pathway is catalyzed by a specific enzyme
- Most pathways are similar in all organisms
- In eukaryotes, most pathways are compartmentalized, making certain reactions occur in certain organelles
- key enzymes will either inhibit or activate which will determine the speed of the reaction
What are redox reactions?
transfer of electrons
What happens in reduction
electron is accepted/gained
what happens in oxidation?
electron is released
Which is in oxidized form:
NADH or NAD+
NAD+
Where does glycolysis take place?
cytoplasm
What are the products of glycolysis?
2 pyruvate
2ATP
2 NADH
Why is the process of glycolysis so long?
To not create too much energy
Why is energy released in glycolysis?
to restart the process
Where does pyruvate oxidation take place?
Mitochondrial matrix
What catalyzes pyruvate oxidation?
enzyme called pyruvate dehydrogenase
What are the products of pyruvate oxidation?
Co2
Acetyl CoA
NADH
What is Acetyl CoA used for?
Starting the citric acid cycle
Where does the citric acid cycle take place?
mitochondrial matrix
What is used to start the citric acid cycle?
Acetyl CoA
Oxaloacetate
How many times does the citric acid cycle occur?
2
What are the products of the citric acid cycle?
6 NADH
CO2
2 FADH2
Oxaloacetate
Why does the citric acid cycle produce oxaloacetate?
To keep the cycle going
Where does the CO2 go?
Used in photosynthesis
Where does the electron transport chain take place?
Mitochondrial matrix
What is the final electron acceptor?
Oxygen
Describe the order of transformations in the electron transport chain
NADH->NAD+ + H+
FADH2-> FAD
2H+ +1/2O2->H2O
What are the two ways that ATP gets synthesized?
Substrate level phosphorylation
Chemiosmosis
What happens in substrate level phosphorylation?
Phosphate + Substrate bind to active site of enzyme, turning ADP to ATP
What happens in chemiosmosis
Hydrogen gradient is used to phosphorylize ADP to ATP
Also uses proton gradient (low and high concentration) where proton moves through ATP synthase and catalyzes in reaction, allowing motor protein to move
During what process is the most ATP made?
electron transport
What is released in cellular respiration?
CO2
What process does CO2 go to?
photosynthesis
What is released in photosynthesis
O2
What process does O2 go to?
cellular respiration
Where does photosynthesis (light reactions) occur?
thylakoid
What is used in photo synthesis?
NADP+ and ADP
What is created in photosynthesis
NADPH (photosystem I)
ATP (photosystem II)
What happens in photosynthesis?
Photon with the correct wavelength brings energy which is passed to chlorophyll to chlorophyll until the center.
Specialized chlorophyll get the energy which turns the electrons to their excited state to become chemical energy
Where is the electron from in photosystem I?
photosystem II
Which pathway takes place in photosystem I?
cyclic pathway
What is in photosystem II?
Water
Oxygen
Reaction center chlorophyll
How is chemiosmosis related to light reactions?
chemiosmosis allows ADP to phosphorylize to ATP using proton gradient
Which pathway makes more ATP than NADPH?
Noncyclic or Cyclic
cyclic
What are the three procceses of the calven cycle
Fixation of CO2
Reduction of ATP and NADPH to form G3P
Regeneration of RuBP
How much CO2 is used in the calvin cycle?
3
What is a product of the calvin cycle?
Sugar
What enzyme is used in the calvin cycle?
rubisco
What is rubisco?
Slow enzyme (a lot of them to make up for it) that catalyzes CO2 to RuBP
Where and when does the calvin cycle take place
In stroma, can occur after daylight but not for long (needs ATP)
What is cAMP?
second messenger
made by adenyl cyclase
activates or inhibits enzymes noncovalently
regulates enzymes
Describe phosphorylation
catalyzed by protein kinase
can inhibit but not always activate
What does protein kinase do?
signals molecules
bind to receptors
uses ATP to activate relay proteins which makes cellular response
List the process of fission
signal from environment
DNA replication
Segregation
Cytokinesis- two new cells
How much NADH does pyruvate oxidation make?
2
How much FADH is made in the calvin cycle
2
How much NADH is made in the calvin cycle?
6
How much total ATP is made in the electron transport chain?
30-34
Where does fermentation occur?
cytoplasm
What does fermentation do?
oxidizes NADH to NAD+
When does fermentation occur?
after glycolysis
