Cellular Respiration pt 1
What are the 4 metabolic reactions in aerobic cellular respiration? Where does each reaction occur spatially in the cell?
Glycolysis- cytoplasm
Break down of pyruvate- mitochondrial matrix
KREBS cycle- mitochondrial matrix
ETC- mitochondrial matrix, inner membrane and intermembrane space
What is photosynthesis? Give a brief description of its purpose and what types of organisms use it directly.
Photosynthesis is the process by which chloroplasts turn light energy into sugar, to be used for energy production in the cell. Plants and cyanobacteria, and algae primarily utilize photosynthesis
Glucose
2NADH
2ATP
2 pyruvate
What is a pigment? What is the name of the pigment that primarily gives plants their green color?
pigments are molecules that absorb light energy.
Chloraphyll
What is the major biological macromolecule responsible for cell cell communication at the plasma membrane?
protein
Hexokinase
What are the two main stages of photosynthesis?
Light reaction and Calvin cycle
What is the first 3 carbon molecule generated during glycolysis, and how many are made?
Glyceroladehyde-3-phosphate, 2 are made
Which organelles is important for photosynthesis? Please describe the detailed structure of the organelle. (you may draw and label if you prefer!)
Chloroplast!
outer membrane, intermembrane space, inner membrane, stroma, thylakoid discs (have lumen inside), stakes of thylakoid discs make up a granum
List 3 of the 5 types of cell cell communication discussed in lecture and explain them.
1. Direct intercellular signaling
2. Contact Dependent signaling
3. Autocrine
4. Paracrine
5. Endocrine
What two molecules combine to start the Citric acid cycle, and what product do they create?
Acetyl-CoA and Oxaloacetate combine to form citrate/citric acid
What is the name of the pigment in PSII and PSI respectfully?
P680
P700
Describe differences between aerobic and anaerobic respiration.
Aerobic requires oxygen. All 4 metabolic reactions can occur in an aerobic condition. Anaerobic conditions are without oxygen. Only glycolysis can persist in making ATP when the cells are in anaerobic conditions.
What is the name of the product generated during the calvin cycle that will be used to generate sugar/carbohydrates, and revive ribulose bisphosphate levels?
Glyceraldehyde-3-phosphate
What are the 4 types of receptors discussed in lecture?
Enzyme linked
GPCR
ligand gated ion channels
intracellular receptors (ex. transcription factors)
Explain how ATP synthase works (generally) through chemiosmosis and the importance of the ETC.
The ETC uses the energy in the transfering electrons to pump H+ions against their concentration gradient from the matrix (H+low) to the inner membrane space (H+high). This concentration gradient stores a lot of potential energy. When the H+ions are allowed to flow down their concentration gradient, they move through ATP synthase. This transforms the potential energy into kinetic. ATP synthase uses this energy to rotate and physically put a iP on ADP to make ATP!
What is the first substrate and product of the calvin cycle? What enzyme catalyzes this reaction?
CO2 molecules are used by the enzyme Rubisco with Ribulose Bisphosphate to form a temporary 6 carbon intermediate, that then turns into 3-phosphoglycerate
Describe the importance and mechanisms of fermentation in relation to oxygen and ATP generation.
Fermentation is an anaerobic reaction that allows for glycolysis and small ATP generation to persist without the presence of oxygen. Fermentation in animal cells turns Pyruvate into lactate/lactic acid through reduction reactions using NADH. This is important to oxidize NADH to NAD+, because NAD+ is needed to accept electrons during glycolysis. If there was no regeneration of NAD+, glycolysis could not persist, the cell would then have no energy being made in anaerobic conditions
What is the importance of water in photosynthesis in terms of electrons and the photosystems?
Water is important because it is oxidized, removing the hydrogens and their electrons and freeing the oxygen. The electrons from the hydrogens are used to replace the excited electrons that left P680 is PSII. This also creates more H+ ions, creating a high concentration in the thylakoid lumen. Additionally, the oxygen forms O2 and is a waste product.
What is apoptosis? Describe one of the two forms of activation.
Apoptosis is programmed cell death
Extrinsic- Death inducing signaling complex (DISC) gets activated by extracellular signaling binding receptors. DISC complex cleaves initiator procaspase to activate it. initiator caspase cleaved executioner procasapse to degrade proteins and kill cell
Intrinsic- response to intracellular stress (ie DNA damage). cytochrome C leaks out of mitochondria and binds the apoptosome. This leads to similar caspase activation as extrinsic pathway
Name all the inner membrane bound components of the ETC in the mitochondria (more than just their complex #!) in order of electron flow and ATP generation.
NADH Dehydrogenase (complex I)
ubiquinone
Succinate Reductase (Complex II)
Cytochrome b-c (Complex III)
Cytochrome C
Cytochrome oxidase (complex IV)
ATP Synthase
Explain the difference between linear electron flow and cyclic electron flow during photosynthesis.
In linear electron flow, the excited electrons from PSII get passed through Pq, cytochrome complex, Pc, PSI, Ferredoxin, then NADP+ Reductase to NADPH
Cyclic flow uses electrons for PSI, to Ferredoxin, to Pq, cytochrome complex, Pc, and then back to PSI to replace the electron used in P700.
How is the flow of electrons different between NADH and FADH2 in the ETC? Also describe the difference in each coenzymes ability to pump hydrogen ions out of the mitochondrial matrix.
NADH is oxidized by NADH Dehydrogenase (Complex I) in the ETC. This complex is the first H+ pump. The electrons from NADH then move through all components of the ETC. FADH2 skips complex I and ubiquinone, and starts at complex II which does not pump H+ ions. NADH leads to more H+ ion movement than FADH2 due to where is starts the oxidation reaction in the ETC.
Describe major differences between C3, C4 and CAM plants.
C3 plants only use Rubisco during carbon fixation, and can incorporate oxygen (photorespiration) in CO2 low environments.
C4 and CAM plants can use PEP carboxylase instead to avoid photorespiration. C4 plants make a lot oxaloacetate in the mesophyl, to be used in the bundle sheath cells (spatial separation). CAM plants also use PEP carboxylase to make oxaloacetate, but separate its generation temporally
Draw and explain the PKA signal transduction pathway in response to epinephrine! Also be sure to explain what is a secondary messenger and its importance!
Ch. 9 slide 37