Bio Unit 3 Test Flashcards
Exergonic reaction
A reaction that has a net release of free energy and is spontaneous
(Ex. Cellular respiration)
Endergonic reaction
A reaction that absorbs free energy from its surroundings and is non spontaneous
(Ex. Photosybthesis)
First law of thermodynamics
-Energy of the universe is constant,
-energy cannot be created or destroyed, but can be transformed and transferred
-Energy flows, matter is recycled
The second law of thermodynamics
-Every energy transfer or transformation increases the entropy of the universe
-Entropy is a measure of molecular disorder
Biological order and disorder
-Organisms create ordered structures from less organized forms of energy and matter
-basically it takes energy to clean your room
Glycolysis
- anaerobic (does not require oxygen)
-takes place in cytoplasm of the cell
-results in 2ATP, 2 Pyruvate, 2 NADH
Link
-aerobic
-takes place in the matrix
-converts pyruvate to Acetyl Co-A
-results in 2 CO2, 2 NADH
Krebs Cycle
-aerobic
-takes place in the matrix
-results in 4 CO2, 2 ATP, 2 NADH, 2 FADH
ETC (electron transport chain)
- aerobic
-takes place across the folded membrane of the matrix called the cristae
-results in 28 ATP
What is the final electron accepter in ETC in cellular respiration?
-Oxygen
What is the final electron accepter in ETC in photosynthesis?
-NADP+, which becomes NADPH once its accepted that electron
What is the difference between NAD+ and NADP+
NAD+ is used in cellular respiration, while NADP+ is used in photosynthesis
How are protons pumped in cellular respiration vrs. photosynthesis?
-In PHOTOSYNTHESIS, protons are pumped INTO the thylakoid, and flow OUT of the ATP synthase
-In CELLULAR RESPIRATION, protons are pumped OUT of the matrix and flow INTO the ATP Synthase
What makes up ATP?
Adenosine Triphosphate, its made of the purine base Adenine, ribose (sugar), and three phosphate groups linked together making the triphosphate
How does ATP supply energy to power metabolic reactions?
ATP powers cellular processes by transferring a phosphate group to another molecule (phosphorylation)
Does the increase of protons lead to a more acidic or basic solution?
More protons result in pH levels below 7, which are more acidic, while more OH- will result in pH levels above 7, making it more basic
What is feedback inhibition in enzymes?
Feedback inhibition is when the reaction’s end product inhibits or controls the enzyme’s function that helped make it
What is an example of feedback inhibition in enzymes?
When an enzymes product becomes an allostatic inhibitor–binding to a non-active sight of the enzyme and rendering it unable to bind to substrates
How does feedback inhibition help achieve efficiency?
When too much or too little of a product is made, the enzyme can tell through feedback inhibition about wether to make more or stop making products
(ex. Krebs cycle is regulated with feedback inhibition in regards to concentration of ATP and NADH)
What does metabolic efficiency mean?
-To prevent energy from being wasted, metabolic pathways are tightly controlled, so if a product isn’t needed, the pathway will shut down to conserve energy
-Metabolic pathways are also localized in specific organelles so that the collected components of the pathway are more easily regulated
What is the difference between cyclic phosphorylation and non-cyclic phosphorylation?
cyclic phosphorylation doesn’t use electrons, and instead cycles the electrons through a pathway
What does the rate of the light independent reaction rely on?
Availability of carbon dioxide
What are the three phases of the Calvin cycle?
Carbon Fixation, Reduction, and Regeneration
What occurs in the Carbon fixation phase of the Calvin cycle?
The enzyme RuBisCo joins 3 CO2 from the atmosphere with 3 RuBP (Ribulose Bisphosphate) to make 6 3-PGA
What occurs during the Reduction phase of the Calvin cycle?
-6 ATP and 6 NADPH (the energy generated from the light dependent reaction) is used to make the 6 molecules of 3-PGA to into 6 molecules of G3P (glycerate 3-phosphate)
-1 of those G3P molecules leaves cycle to make other organic molecules
What occurs during the Regeneration phase of the Calvin cycle
-5 G3Ps combine with 3 ATP to form 3RuBP, regenerating the RuBP used up earlier, and starting the cycle over again
G3P (glyceraldehyde 3-phosphate) can be used by plants to make:
Sucrose and Starch
What are photo stems 1 and 2 responsible for?
-are embedded in the thylakoid membranes
-a part of photophosphorylation
-pass electrons through an electron transport chain
In photophosphorylation, what happens as a result of electrons passing through an electron transport chain?
-hydrogen ions (protons) allowed across membrane
-forms a proton gradient that powers process of ATP synthesis
