Answer:
4) Each cytochrome has an iron‑containing heme group that accepts electrons and then donates the electrons to a more electronegative substance.
Explanation:
The cytochromes are <u>proteins that contain heme prosthetic groups</u>. Cytochromes <u>undergo oxidation and reduction through loss or gain of a single electron by the iron atom in the heme of the cytochrome</u>:

The reduced form of ubiquinone (QH₂), an extraordinarily mobile transporter, transfers electrons to cytochrome reductase, a complex that contains cytochromes <em>b</em> and <em>c₁</em>, and a Fe-S center. This second complex reduces cytochrome <em>c</em>, a water-soluble membrane peripheral protein. Cytochrome <em>c</em>, like ubiquinone (Q), is a mobile electron transporter, which is transferred to cytochrome oxidase. This third complex contains the cytochromes <em>a</em>, <em>a₃</em> and two copper ions. Heme iron and a copper ion of this oxidase transfer electrons to O₂, as the last acceptor, to form water.
Each transporter "downstream" is <u>more electronegative</u><u> than its neighbor </u>"upstream"; oxygen is located in the inferior part of the chain. Thus, the <u>electrons fall in an energetic gradient</u> in the electron chain transport to a more stable localization in the <u>electronegative oxygen atom</u>.
Answer:
100,000 N
Explanation:
Force, F = mass, m × acceleration, a
⇒F = ma
m= 20, 000kg
a = 5m/s²
∴ F = 5 × 20,000 = 100,000N
Answer: The answer is the second one
very cold temperatures
Explanation:
A superconductor performs best at very cold temperatures.
A superconductor is a perfect conductor that is able to allow the passage of electricity and heat without resistance.
- In superconductors, under certain conditions, resistance ceases to exist.
- Examples are aluminium, niobium e.t.c
- A conductor allows heat and current to pass through but with little resistance.
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Metals brainly.com/question/2474874
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