Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


Each round of the Krebs cycle liberates
two carbon dioxide molecules.
At the end of the cycle all carbon atoms
from thdegraded in glycolysise original glucose m are alroleculeeady
liberated incorporated into carbon
dioxide molecfor each glucose two pules. That occuyruvic acidrs because
molecules were made by glycolysis.


Each of these two pconverted into acetyl CoA with libyruvic acids then iseration (^)
of one carbon dioxide molecule (two in
total). Since acetyl CoA cycles the Krebs cycle onceach of the two producede, (^)
from ththe Krebs cycle ise initial glucose two r generated and so fourounds of (^)
other carbon dioxide molecules are
made.
All of the six carbons of the glucose
molecule are then incorporated carbon dioxide molecules (two mainto sixde
during acetyl CoA formation and four
during the two cycles ocycle). f the Krebs



  1. Where in mitochondria
    does the process called
    respiratory chain occur?
    Which are the products of the
    Krebs cycle used in that final
    phase of the aerobic
    respiration?


Respiratory ctransport chain, is phain, or erformed by proteinthe electron (^)
systemsof the mitocho located indria. En the inner membranenergized electrons (^)
of hydrogen atoms transported by
NADHthe preceding phases us 2 and FADH 2 are the products ofed in the
respiratory chain.



  1. What are cytochromes?
    Cytochromes are proteins of the internal


mitochospecialized indrial mn electron transfembrane that areer and (^)
participate in the respiratory chain.
Energized electrons lihydrogen donors NADHberated by the
(then reconverted into NAD and FAD)^2 and FADH^2
pass through a sequence ofcytochromes losing energy in each (^)
passage. Tsynthesis of ATP.he energy is then used in the



  1. How in the respiratory
    chain do electrons from FADH 2
    and NADH 2 passing through
    cytochromes liberate energy
    for the ATP synthesis? What is
    this ATP synthesis called?


FADHNAD and liberate 2 and NADH (^2) hydrogen ions an oxidate into FAD dand
highly energized electronsbeginning of the respiratory chain. in the
The energy lostthrough the cytochrom by electrons that pes is used toass
pump protons (the inner mitochonhydrogen ions) out ofdrial membrane (to (^)
the region between the inner and the
outer mmitochoembranes ondrion). Hydrogen concentrationf the (^)
gradient between the inner and the
outer spaces delimited bmembrane forces protons (y the innerhydrogen (^)
ions) to return to the mitochondrial
matrix (thmembrane) however that return is onlye region inside the inner (^)
possible if hydrogen ions pass through
an enzymaticsynthetase em complex callebedded in the innerd ATP (^)
membrane. In that passage the ATP
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