September 15, 2023 Flashcards
what is gene expression
process by which information encoded in a gene is used to produce a functional gene product
how does a change in gene expression occur
often involves turning a gene on (increasing expression) or off (decreasing expression) in response to specific signals or environmental conditions
what are the products of the krebs cycle
1 NADH2
1 FADH2
2 CO2
1 ATP
where are triglycerides stored
within adipose tissue(body fat)
what do triglycerides break down into
fatty acids and glycerol.
what is a mono unsaturated fatty acid
a type of fatty acid that contains one double bond within its carbon chain.
what is a cis fatty acid
A cis fatty acid is a type of unsaturated fatty acid in which the hydrogen atoms attached to the carbon atoms adjacent to a double bond are positioned on the same side (or same face) of the carbon-carbon double bond.
what is a trans fatty acid
A trans fatty acid (trans fat) is a type of unsaturated fatty acid in which the hydrogen atoms attached to the carbon atoms adjacent to a double bond are positioned on opposite sides (or opposite faces) of the carbon-carbon double bond.
explain the Fatty acids B-oxidation cycles
a metabolic pathway within cells that breaks down fatty acids into acetyl-CoA molecules, which can then be used as a source of energy through the citric acid cycle (also known as the Krebs cycle) and the electron transport chain.
This process occurs primarily in the mitochondria
how many cycles does it take to get 9 Acetyl CoA from a C18 fatty acid
8 cycles
One less cycle than the number of Acetyl CoA
How many FADH2 and NADH does the B-oxidation cycles produce from fatty acid(C18)
8 cycles = 8 FADH2 and 8 NADH
where does Nadh enter in the electron transport chain
NADH (nicotinamide adenine dinucleotide, reduced form) enters the electron transport chain (ETC) at the first protein complex of the chain, which is known as Complex I (also called NADH dehydrogenase
where does FADH2 enter in the electron transport chain
FADH2 (flavin adenine dinucleotide, reduced form) enters the electron transport chain (ETC) at a later point than NADH. FADH2 donates its high-energy electrons to the ETC at Complex II (also known as succinate dehydrogenase).
explain the steps involved in the Electron Transport Chain
- Complex I (NADH Dehydrogenase):
The process begins when electrons are donated by NADH produced during previous stages of cellular respiration, such as glycolysis and the citric acid cycle. NADH donates its electrons to Complex I.
Proton Pumping: As electrons move through Complex I, the energy released is used to pump protons (H+ ions) across the inner mitochondrial membrane, creating a proton gradient with a higher concentration of protons in the intermembrane space.
2.Ubiquinone (Coenzyme Q):
Electron Transfer: Electrons from Complex I are transferred to ubiquinone (also known as coenzyme Q), a mobile electron carrier located within the inner mitochondrial membrane.
Proton Pumping: As electrons move through ubiquinone, some protons are pumped across the inner mitochondrial membrane.
3.Complex II (Succinate Dehydrogenase):
Electron Donation: In addition to NADH, electrons can also enter the ETC via FADH2 produced during the citric acid cycle. FADH2 donates its electrons to Complex II.
Electron Transfer: Complex II transfers these electrons to ubiquinone.
Proton Pumping: Like Complex I, Complex II also contributes to proton pumping.
4.Complex III (Cytochrome bc1 Complex):
Electron Transfer: Ubiquinone carries the electrons from both Complex I and Complex II to Complex III.
Proton Pumping: Complex III continues to pump protons into the intermembrane space.
5.Cytochrome c:
Electron Shuttle: Electrons from Complex III are transferred to a small protein called cytochrome c, which shuttles the electrons between Complex III and Complex IV.
6.Complex IV (Cytochrome c Oxidase):
Electron Transfer: Cytochrome c donates its electrons to Complex IV.
Final Electron Acceptor: In Complex IV, the electrons are ultimately transferred to molecular oxygen (O2), which serves as the final electron acceptor in the ETC. This results in the formation of water (H2O).
Proton Pumping: Complex IV also pumps protons across the inner mitochondrial membrane.
5.Proton Gradient and ATP Synthesis:
The protons pumped into the intermembrane space create a proton gradient or electrochemical gradient.
Protons flow back into the mitochondrial matrix through ATP synthase (Complex V), which harnesses the energy from this proton flow to convert adenosine diphosphate (ADP) and inorganic phosphate (Pi) into ATP, the cell’s primary energy molecule.
what regulates the movement of the ETC
regulated by the availability of free ADP
