Chapter 7 Flashcards
what is cellular respiration?
a series of oxidation reduction reactions
what is needed to move electrons from one molecule to the next?
electron transporters
is NAD+ oxidized or reduced and why?
oxidized, it lost an electron
is NADH oxidized or reduced and why?
reduced, it gained an electron
what is the energy currency of the cell and the ultimate goal of cellular respiration?
ATP
what do you get by oxidizing glucose?
ATP
what are the 4 major steps of cellular respiration?
glycolysis, pyruvate oxidation, krebs cycle, electron transport chain and chemiosmosis
where do MOST cellular respiration reactions take place in eukaryotes?
mitochondria
do any cellular respiration reactions take place in the mitochondria in prokaryotes? why or why not?
no, they don’t have membrane-bound organelles, which is what mitochondria is
who makes more ATP from one molecule of glucose?
eukaryotes
what is the highly folded inner membrane of mitochondria called?
cristae
why are the folds of cristae important?
lots of surface area for enzymatic reactions
what is the gel in between the cristae of the mitochondria?
the matrix
what does the matrix house?
reactants
what is the outermost layer of the mitochondria called?
outer membrane
what is the space between the cristae and the outer membrane of the mitochondria called?
intermembrane space
where does glycolysis take place?
cytoplasm
how many reactions are in glycolysis from start to finish?
10
what are the reactants for glycolysis?
glucose (1), ATP (2), NAD+ (2), ADP (2)
what are the produtcs of glycolysis?
pyruvate (2), H20 (2), NADH (2), ATP (4)
are there any cofactors or coenzymes used in glycolysis?
no
how much ATP is made in glycolysis?
4 total, but only 2 net that the body can use, because it needs 2 ATP to start glycolysis
how is ATP made in glycolysis?
substrate level phosphorylation
where does pyruvate oxidation take place?
in the mitochondria’s inner membrane
what happens to all of the products and reactants starting with pyruvate oxidation and why?
everything happens twice because there are two pyruvate molecules going through the following reactions and steps
what are the reactants for both molecules of pyruvate for pyruvate oxidation?
pyruvate (2), CoA (2), NAD+ (2)
would be 1, 1, 1 for one molecule
what are the products for both molecules of pyruvate for pyruvate oxidation?
Acetyl CoA (2), CO2 (2), NADH (2) would be 1, 1, 1 for one molecule
are the any cofactors/coenzymes used in pyruvate oxidation?
yes, CoA, one molecule is used for each molecule of pyruvate
how much ATP is made during pyruvate oxidation?
none
how much net ATP is made after pyruvate oxidation?
2 molecules
how is ATP made during pyruvate oxidation?
it’s not
how is the CO2 released during pyruvate oxidation?
as waste
what is the third step of cellular respiration?
the Kreb’s cycle
where does the krebs cycle take place?
in the mitochondrial matrix
what are the reactants for both molecules of pyruvate in the krebs cycle?
Acetyl CoA (2), oxaloacetate (2), NAD+ (6) FAD (2), ADP + P (2) would be 1, 1, 3, 1,1 for one molecule
what are the products for both molecules of pyruvate from the krebs cycle?
CoA (2), oxaloacetate (2), NADH (6), FAHD2 (2), ATP (2), CO2 (4)
would be 1, 1, 3, 1, 1 for one molecule
are there any cofactors/coenzymes used in the krebs cycle?
yes CoA, one CoA is released from each molecule of Acetyl CoA
how much ATP is made in the krebs cycle?
2 molecules
how much net ATP is made by cellular respiration at the end of the krebs cycle?
4 molecules
how is ATP made in the krebs cycle?
substrate level phosphorylation
where does the electron transport chain (ETC) and chemiosmosis take place?
in the mitochondrial matrix and intermembrane space
what are the reactants for the ETC and chemiosmosis?
NADH (10), FADH2 (2), OXYGEN, and H+ ions
what are the products of the ETC and chemiosmosis?
ATP (30-38ish), H20
are there any cofactors/coenzymes for the ETC ad chemiosmosis?
no
how much ATP is made by the ETC and chemiosmosis?
approximately 30-38ish
how is ATP made by the ETC and chemiosmosis?
chemiosmosis
what makes up the ETC?
a series of enzymes and proteins
what is the final electron acceptor?
oxygen
what happens to the NADH molecules as electrons are bounced down the ETC?
they are oxidized to NAD+
where do the H+ ions move in the ETC, and why is this important?
from the matrix to the intermembrance space, building up a concentration gradient inside the intermembrane space
how it ATP synthase powered?
the concentration gradient of the buildup of H+ ions
what does ATP synthase do?
rotates and twists, transferring enough energy to squeeze an ADP + P together to make ATP (chemiosmosis) and shoots that ATP out of the mitochondria
what is needed to begin cellular respiration?
1 molecule of glucose and 2 molecules of ATP
what is the overall chemical formula for cellular respiration?
C6H12O6 + 6O2 —–> 6CO2 + 6H2O + ATP (30-38)
where is CO2 exhaled as waste during cellular respiration?
pyruvate oxidation and krebs cycle
what is anaerobic respiration?
happens in the absence of oxygen
list the 2 main forms of anaerobic respiration?
lactic acid and alcohol fermentation
what step of cellular respiration is anaerobic?
glycolysis
what happens to pyruvate after glycolysis in lactic acid fermentation?
NADH is oxidized to NAD+ and produces lactate and no additional ATP
what happens to pyruvate after glycolysis in alcohol fermentation?
pyruvate produces CO2 as waste to make acetaldehyde, which makes ethanol by oxidizing NADH to NAD+ and no more additional ATP is made
what is oxidative phosphorylation?
chemiosmosis
where can some carbohydrates, amino acids, and glycerol enter cellular respiration?
glycolysis
where can fatty acids and some amino acids enter cellular respiration?
pyruvate oxidation
where can come amino acids enter cellular respiration?
Krebs cycle/citric acid cycle
how is cellular respiration regulated?
negative feedback
how does negative feedback regulate cellular respiration?
some of the products inhibit some of the enzymes required for cellular respiration
what does ADP activate?
an enzyme for glycolysis
why is it important that ADP activates an enzyme for glycolysis?
because if there is only ADP detected, and not ATP, glycolysis will start again to produce more ATP for the cell to use
what does ATP inhibit?
an enzyme for glycolysis (phosphofructokinase)
why is it important that ATP inhibits an enzyme for glycolysis?
if too much ATP (or an adequate amount) is detected, the cell does not have to waste energy to make more energy
how many enzymes does NADH inhibit?
2
define phosphorylation
the addition of the phosphate (P) to ADP
define substrate level phosphorylation
when ATP is regenerated from ADP through the removal of a phosphate group from an intermediate reactant in the pathway, and the free energy of that reaction is used to add the phosphate to an available ADP molecule
what is the first half of glycolysis called?
energy requiring steps
what is the second half of glycolysis called?
energy releasing steps
what is the only part of cellular respiration that uses atmospheric oxygen?
electron transport chain