Final Exam Flashcards
What is the products of the Krebs Cycle? Rank them lowest energy to highest.
ATP, CO2 and Electrons and Protons in NADH and FADH2.
ATP –> FADH2 –> NADH
Why does NADH have a lot of energy?
It creates 3 ATP molecules.
How do the carbons go in Krebs/Citric acid cycle?
2 Carbon –> 6 Carbon –> 5 carbon –> 4 carbon –> 2 carbon.
How does the total cycle go to make ATP?
Glycolysis breaks down glucose (creates 2 pyruvate, 3 carbon) –> Pyruvate turns into 2 carbon molecules Acetyl CoA goes through membrane —> Krebs cycle –> Oxidative Phosphorylation. Moves e’ to create gradient.
What are NADH and FADH2?
They are coenzymes that ferry electrons into ETC.
What does beta oxidation do, where does it happen?
Breaks down fatty acids, happens in mitochrondria.
Where does Krebs cycle happen?
Lumen of mitochondria.
Why are carbon and nitrogen not available in gaseous forms?
They are chemically inert and don’t react with anything so they need to be fixed to another molecule, this is why carbon and nitrogen fixation are important.
What do plants do in photosynthesis?
They turn CO2 and H2O into sugar.
What does N2 get turned into?
NH3 (ammonia)
Can eukaryotes fix carbon and nitrogen?
No. They are heterotrophs.
What are autotrophs?
Plants.
Why can plants fix sugars even though they are eukaryotes?
They have prokaryotes inside them, came from cyanobacteria.
Why does NH3 get excreted?
When amino acids are broken down the methyl side group gets excreted as NH3.
What is carbon fixation?
When CO2 get fixed into another molecule.
What does oxygenic photosynthesis produce?
O2
What bacteria gave plants the ability to photosynthesize?
Cyanobacteria
What is a pigment?
A pigment is any colored molecule.
What pigments are in photosynthesis?
Chloryphyll A, B and carotenoids.
What helps in photosynthesis to get light waves?
Carotenoids, xanthopylls capture all lights, except green.
Why are plants green?
Because green does not get absorbed, whatever is not absorbed is the color you see.
What is a chloroplast made of?
-double layer clear outer membrane.
-Stacks of thylakoids, like coins, called granum.
-Stroma is fluid.
-photosynthetic part is inside chloroplast.
What is the antenna complex where is it located?
Located in PS2 and PS1, captures enough energy to knock electrons from pigments into ETC.
Which comes first in the Photosystems?
PS2 then PS1 knocks electrons off water.
What is linear electron flow?
Linear electron flow pumps out NADPH and ATP.
What does cyclical electron flow do?
Cyclical electron flow only makes ATP, electron goes from PS1 out of PS1 and back to it.
What is the purpose of the Calvin Cycle?
CO2 + NADPH + ATP = G3P sugar
What happens in Calvin Cycle?
1) Carbon Fixation - Add one CO2 to a 5 carbon molecule, as carboxyl.
2) Reduction - Add electrons and protons to 3 carbon molecule.
3) Regeneration - Recreate original 5 carbon molecule.
What is G3P?
3 carbon sugar molecule called Glyceraldehyde 3-phosphate.
Where are the light reactions?
In Thylakoids, splits H2O.
Where does the Calvin cycle take place?
In the Stroma.
What is Rubisco?
Rubisco (= ribulose bisphosphate carboxylase)
Takes carbon out of CO2 and fixes to organic compound.
What are 3 types of cell communication?
1) neural signaling
2) Paracrine signaling
3) Endocrine signaling
What is neural signaling?
Nerve cells have contact with each other and relay from nerve cell to nerve cell.
What is paracrine signaling?
Some signal molecules diffuse over a short distance in tissue for nearby cells.
What is endocrine signaling?
Signal molecules go into bloodstream and circulate to target cells throughout the body.
What are cell junctions?
Gap between touching cells, membrane proteins line up to make channels.
What is cell to cell recognition?
Lock and key fit, protein receptors outside cell receive signal molecules.
What does cell signaling do?
It can activate or deactivate genes in nucleus, or another cellular process.
What are hormones?
Signal molecules that go through bloodstream, can be thyroid or steroid hormones.
What are steroid hormones made from? Where are they made?
Cholesterol, they can go through cell membrane easily, made in gonads and adrenal glands. Affect physiological things.
What are thyroid hormones? What do they do? What are they made of?
They control metabolic functions such as energy output, made of Thyroxine (T4) and triiodothyronine (T3), made of amino acid tyrosine with iodine attached.
Do steroids and hormones pass through cell membranes?
Yes and bind to a receptor protein in cytoplasm which then can go into nucleus and activate/deactivate gene.
Can most signal molecules go through membrane?
No.
What is a transduction pathway?
Signaling molecule binds to protein in membrane starting a cascade of protein kinases.
What are protein kinases?
An enzyme that phosphorylates a target protein with ATP, cascades and each keep changing another until signal is reached.
What is a GPCR? How many are there?
G protein couple receptor, ~800 in humans.
What is the structure of GPCR?
7 Alpha helixes, with a hydrophobic middle part, they are transmembrane protein. N terminal outside cell, C terminal inside cell.
How do GPCRs work?
They are bound to GDP (guanosine diphosphate). When signal molecule binds to outside cell, it activates G-Protein inside cell. Binds to GTP then g protein leaves GCPR goes and activates some other molecule. GTP ends as GDP again.
In general, describe the journey taken by proteins, lipids, and carbohydrates as they move and change to become usable energy.
They move from their original form, to then become an amino acid, a fatty acid or a sugar, which then becomes aecytl coA, which then enters to Krebs cycle, which then enters the Electron transport chain in oxidative phosphorylation all to make ATP.