EXAM 2 Review Flashcards
(29 cards)
Describe membrane synthesis steps
- Membrane is formed by the ER
- Membranes get transported to the cytosolic half of the ER membrane
- Scramblase will evenly distributed the ER membrane
- Unused membrane get transported to the golgi
- Flippase will remove specific phospholipids from the exterior space and flip them into the cytosolic side.
- Phospholipids get transported via vessicles to the bilayer
ER - > Scramblase -> GA -> Flippase -> Cellular Membrane
How do cells restrict protein movement?
Proteins are restricted via protein domain.
Some proteins such as cell cortex and tight junction restrict protein
What are the different types of membrane transport?
Simple diffusion: diffusion that does not require the help of transport protein - passive
Facilitated Diffusion: Diffusion of solute with the assistance of protein. There are two types: Ion channels (only passive) and transporter (passive or active)
Active Transport: Using energy to diffuse solute against its concentration gradient
Can a transport have both active and passive transport occuring?
Yes
In the case of the Glucose-Na+ symport, glucose is moving against its concentration gradient (active) while Na+ is moving with its concentration gradient (passive)
Describe the Na/K ATPase cycle
- 3 sodium ions bind with the carrier protein, leading to conformational change
- Carrier Protein is phosphorylated
- Sodium is released from the conformation change of the phosphorylation
- Potassium ion binds to the carrier protein
- Protein carrier dephosphorylate, leading to conformational change
- Conformational change release potassium into the cell
Why is it important to create ion gradient across the membrane?
To create energy to power transport across the membrane; cell use gradient to move along
What is Nernst Equation?
V = 62 log (Co /Ci)
What is Nernst Equation?
V = 62 log (Co /Ci)
Describe the 7 steps of an action potential
- Na channel open from a stimulus (change in voltage)
- If the threshold is achieved, Na channels will further opening, causing action potential to occur
- Rapid depolarization from Na+ flooding into the cell
- Na channel become inactivated by closing once the equilibrium potential is +50
- K channel opens
- K+ leave the cell, repolarizing the cell back to the negative potentials
- K channel close
What happen when action potential reaches the end of an axon?
- The action potential will cause Ca channel to open, releasing Ca2+ in
- Ca trigger fusion of vesicle containing neurotransmitter to the synaptic cleft
- Neurotransmitter will bind to ligand gated channel receptors of the post synaptic cleft, propagating signal forward
What can be the results of information being passed between neurons?
Excitatory or inhibitory response may occur
Describe the process of how glucose is processed in the presence of oxygen.
- Glycolysis: 2 pyruvates are made in cytosol.
- Pyruvate is converted into acetyl CoA and carbon dioxide by the dehydrogenase complex in the mitochondrial matrix.
- acetyl coA goes into the citric acid cycle, bonds into oxaloacetate, release Co2 as waste, and produce NADH in the mitochondrial matrix.
4.NADH produced by the citric acid cycle is used as an electron donor for the ETC
- Electron makes its way in the ETC, releasing protons that produces a gradient for ATPase to produce ATP
- Oxygen accepts electron at the end of the ETC, forming water as a biproduct
Why is oxygen important as an electron donor in the mitochondrial ETC?
If oxygen does not accept, then the electrons will be backed up and oxidative phosphorylation cannot happen; no ATP can be produced.
Describe the (condensed) steps of glycolysis
- Glucose is phosphorylated (First ATP invested) by hexokinase to form glucose 6-phosphate
- Glucose 6 phosphate rearrange into fructose- 6-phosphate
- Fructose-6-phosphate is phosphorylated (Second ATP invested) to form fructose 6-biphosphate
- Fructose-6-biphosphate is cleaved by aldolase into 2 3-carbon molecule. The other 2 3-carbon molecule will rearrange itself into an aldehyde.
- The 3-carbon aldehyde will oxidized into carboxylic acid, releasing an ATP
- The carboxylic acid will undergo further rearrangement
- The finalized compound will be catalyzed by pyruvate kinase to form pyruvate and ATP.
Describe the (condensed) steps of the citric acid cycle
- Citrate Synthase (step1)
- Two carbons from acetyl CoA to oxaloacetate to form citrate. - Release of Carbon Dioxide
- Two molecules of CO2 are released; acetyl CoA oxidized into CO2 - Malate Dehydrogenase (step8); Oxaloacetate is regenerated
- Malate molecule is oxidized into oxaloacetate and the produced oxaloacete will enter into the next cycle with the next acetyl coA
Describe the flow of electron in the mitochondrial ETC
Electron flow from
NADH -> NADH Dehydrogenase Complex -> Ubiquinone
-> Cytochrome B-c1 complex -> Cytochrome C -> Cytochrome Oxidase Complex
What are the roles of all the components of the mitochondrial ETC?
NADH: donate electron to NADH Dehydrogenase complex
NADH Dehydrogenase Complex: Convert H- into H+ and 2 electrons
Ubiquinone: Transport electron from NADH Dehydrogenase complex to Cytochrome B-c1 complex
Cytochrome B-c1 (reductase) complex: Pump a hydrogen ion out and deliver electron to Cytochrome C
Cytochrome C: Transport electron from Cytochrome B-c1 complex to Cytochrome Oxidase complex
Cytochrome oxidase complex: Remove electron from cytochrome c, oxidizing cytochrome c and deliver electron to oxygen reducing it to water.
What happens to the redox potential as an electron move along the ETC?
Redox potential increase
What are the components to the chloroplast ETC
- Photosystem II
Special Pair (Water splitting enzyme) -> Plastoquinone -> Cytochrome b6-f complex - Photosystem I
-> Plastocyanin -> Ferredoxin -> Ferredoxin-NADPH reductase -> NADPH terminal electron acceptor
What are the roles of all the components of the chloroplast ETC?
Special Pair: Remove electron from water molecule, releasing oxygen (the one we breath) in to the air
Plastoquinone: Take electron from special pair and transport it to cytochrome b6-f complex
Cytochrome b6-f complex: Mediate the transfer of electron from photosystem II to photosystem I
Plastocyanin: Transfer electron from cytochrome b6-f complex to ferredoxin
Ferredoxin: Takes electron from plastocyanin to ferredoxin NADPH reductase
NADPH Reductase: Use the electron to reduce NADP+ to NADPH; NADPH is regenerated
NADPH is used for the calvin cycle
Why is NADPH so important after it’s produced by the light dependent reaction?
NADPH is used in the calvin cycle
Why is light so important for photosystem II and I?
Light produce charge separation, allowing for electrons to be excited to transport itself from one molecule to another
What is the purpose of the calvin cycle?
Use the ATP and NADPH produced from the light dependent reaction stage to synthesize carbohydrate
Describe the calvin cycle
- Carbon Fixation
- 3 CO2 combines with 3 Rubisco to make 6 3-phosphoglycerate. - Sugar Formation
-ATP and NADPH are consumed to convert 3-phosphoglycerate to glyceraldehyde 3-phosphate. - Regeneration of Rubisco
- 5 of the 6 glyceraldehyde 3-phosphate and 3 ATP are used to regenerate 3 Rubisco that is used for the next cycle
